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Sample records for food spoilage bacterium

  1. Genome Sequence of a Food Spoilage Lactic Acid Bacterium, Leuconostoc gasicomitatum LMG 18811T, in Association with Specific Spoilage Reactions ▿ †

    Science.gov (United States)

    Johansson, Per; Paulin, Lars; Säde, Elina; Salovuori, Noora; Alatalo, Edward R.; Björkroth, K. Johanna; Auvinen, Petri

    2011-01-01

    Leuconostoc gasicomitatum is a psychrotrophic lactic acid bacterium causing spoilage of cold-stored, modified-atmosphere-packaged (MAP), nutrient-rich foods. Its role has been verified by challenge tests in gas and slime formation, development of pungent acidic and buttery off odors, and greening of beef. MAP meats have especially been prone to L. gasicomitatum spoilage. In addition, spoilage of vacuum-packaged vegetable sausages and marinated herring has been reported. The genomic sequencing project of L. gasicomitatum LMG 18811T was prompted by a need to understand the growth and spoilage potentials of L. gasicomitatum, to study its phylogeny, and to be able to knock out and overexpress the genes. Comparative genomic analysis was done within L. gasicomitatum LMG 18811T and the three fully assembled Leuconostoc genomes (those of Leuconostoc mesenteroides, Leuconostoc citreum, and Leuconostoc kimchii) available. The genome of L. gasicomitatum LMG 18811T is plasmid-free and contains a 1,954,080-bp circular chromosome with an average GC content of 36.7%. It includes genes for the phosphoketolase pathway and alternative pathways for pyruvate utilization. As interesting features associated with the growth and spoilage potential, LMG 18811T possesses utilization strategies for ribose, external nucleotides, nucleosides, and nucleobases and it has a functional electron transport chain requiring only externally supplied heme for respiration. In respect of the documented specific spoilage reactions, the pathways/genes associated with a buttery off odor, meat greening, and slime formation were recognized. Unexpectedly, genes associated with platelet binding and collagen adhesion were detected, but their functionality and role in food spoilage and processing environment contamination need further study. PMID:21571876

  2. Food spoilage - interactions between food spoilage bacteria

    DEFF Research Database (Denmark)

    Gram, Lone; Flodgaard, Lars; Rasch, Maria

    2002-01-01

    Food spoilage is a complex process and excessive amounts of foods are lost due to microbial spoilage even with modem day preservation techniques. Despite the heterogeneity in raw materials and processing conditions, the microflora that develops during storage and in spoiling foods can be predicted...... based on knowledge of the origin of the food, the substrate base and a few central preservation parameters such as temperature, atmosphere, a(w) and pH. Based on such knowledge, more detailed sensory, chemical and microbiological analysis can be carried out on the individual products to determine......-regulation of phenotypes potentially involved in spoilage through cell-to-cell communication. In particular, we report for the first time the widespread occurrence of N-acyl homoserine lactones (AHL) in stored and spoiling fresh foods and we discuss the potential implications for spoilage and food preservation....

  3. Moulds in food spoilage

    DEFF Research Database (Denmark)

    Filtenborg, Ole; Frisvad, Jens Christian; Thrane, Ulf

    1996-01-01

    There is an increasing knowledge and understanding of the role played by moulds in food spoilage. Especially the discovery of mycotoxin production in foods has highligh-ted the importance of moulds in food quality. It is, however, only within the last 5-10 years that major progresses have been made...... towards the prevention of spoilage caused by moulds. This is due to recent international agreements on taxonomy and analytical methods for foodborne moulds, which has led to the discovery, that a specific, very limited funga (=mycobiota) is responsible for the spoilage of each kind of food. This is called...... of foods. The important mycotoxin pattern of each food is described including toxins which originates from "carry over". For some foods examples are also given on spoilage of sensoric properties due to moulds. Finally, preventi-ve actions towards the growth of the associated funga is described for some...

  4. Moulds in food spoilage

    DEFF Research Database (Denmark)

    Filtenborg, Ole; Frisvad, Jens Christian; Thrane, Ulf

    1996-01-01

    There is an increasing knowledge and understanding of the role played by moulds in food spoilage. Especially the discovery of mycotoxin production in foods has highligh-ted the importance of moulds in food quality. It is, however, only within the last 5-10 years that major progresses have been made...... towards the prevention of spoilage caused by moulds. This is due to recent international agreements on taxonomy and analytical methods for foodborne moulds, which has led to the discovery, that a specific, very limited funga (=mycobiota) is responsible for the spoilage of each kind of food. This is called...... the associated or critical funga and has been shown to consist of less than 10 species. In this paper the associated funga is described for the following foods: Citrus and pomaceous fruits, potato and yam tubers, onions, rye, wheat, rye bread, cheese and fermented sausages and whenever possible the selective...

  5. Comparison of adhesion of the food spoilage bacterium Shewanella putrefaciens to stainless steel and silver surfaces

    DEFF Research Database (Denmark)

    Hjelm, Mette; Hilbert, Lisbeth Rischel; Møller, Per

    2002-01-01

    The aim of this study is to compare the number of attached bacteria, Shewanella putrefaciens, on stainless steel with different silver surfaces. Thus evaluating if silver surfaces could contribute to a higher hygienic status in the food industry. Bacterial adhesion to three types of silver surfaces...... than one log unit in bacterial numbers on the two types of materials was observed, but for most samples the difference was within one log unit. Treating new silver with sulphide to try to reproduce a tarnished silver surface did not result in a similar lowering of adhering cells when compared to steel...

  6. Solving Microbial Spoilage Problems in Processed Foods

    Science.gov (United States)

    Clavero, Rocelle

    This chapter surveys common microbial food spoilage processes. The chapter is organized by food products and includes sections addressing spoilage in meat, poultry, fish; dairy products (milk, butter, cheese); beverage products; bakery products; canned foods; fruit and confectionery products; and emulsions. It addresses the isolation and identification of spoilage organisms and provides several case studies as examples. It introduces various organisms responsible for spoilage including Gram-positive lactic acid bacteria, Gram-negative aerobic bacteria, yeasts, molds, and fungal contaminants. Throughout the chapter, attention is given to when, where, and how spoilage organisms enter the food processing chain. Troubleshooting techniques are suggested. The effect (or lack of effect) of heating, dehydration, pH change, cooling, and sealing on various organisms is explained throughout. The chapter contains four tables that connect specific organisms to various spoilage manifestations in a variety of food products.

  7. Microbiological Spoilage of Canned Foods

    Science.gov (United States)

    Evancho, George M.; Tortorelli, Suzanne; Scott, Virginia N.

    Nicolas Appert (1749-1841) developed the first commercial process that kept foods from spoiling in response to an offer from the French government for a method of preserving food for use by the army and navy. Appert, a confectioner and chef, began to experiment in his workshop in Massy, near Paris, but since little was known about bacteriology and the causes of spoilage (Louis Pasteur had yet to formulate the germ theory), much of his work involved trial and error. In 1810, after years of experimenting, he was awarded the prize of 12,000 francs for his method of preservation, which involved cooking foods in sealed jars at high temperatures. He described his method of preserving food in a book published in 1811, "L'Art De Conserver, Pendant Plusiers Annes, Toutes les Substances Animales et Végétales," which translated means "The Art of Preserving All Kinds of Animal and Vegetable Substances for Several Years." He later built a bottling factory and began to produce preserved foods for the people of France and is credited with being the "Father of Canning."

  8. Undergraduate Laboratory Exercises Specific to Food Spoilage Microbiology

    Science.gov (United States)

    Snyder, Abigail B.; Worobo, Randy W.; Orta-Ramirez, Alicia

    2016-01-01

    Food spoilage has an enormous economic impact, and microbial food spoilage plays a significant role in food waste and loss; subsequently, an equally significant portion of undergraduate food microbiology instruction should be dedicated to spoilage microbiology. Here, we describe a set of undergraduate microbiology laboratory exercises that focus…

  9. Sea salts as a potential source of food spoilage fungi.

    Science.gov (United States)

    Biango-Daniels, Megan N; Hodge, Kathie T

    2018-02-01

    Production of sea salt begins with evaporation of sea water in shallow pools called salterns, and ends with the harvest and packing of salts. This process provides many opportunities for fungal contamination. This study aimed to determine whether finished salts contain viable fungi that have the potential to cause spoilage when sea salt is used as a food ingredient by isolating fungi on a medium that simulated salted food with a lowered water activity (0.95 a w ). The viable filamentous fungi from seven commercial salts were quantified and identified by DNA sequencing, and the fungal communities in different salts were compared. Every sea salt tested contained viable fungi, in concentrations ranging from 0.07 to 1.71 colony-forming units per gram of salt. In total, 85 fungi were isolated representing seven genera. One or more species of the most abundant genera, Aspergillus, Cladosporium, and Penicillium was found in every salt. Many species found in this study have been previously isolated from low water activity environments, including salterns and foods. We conclude that sea salts contain many fungi that have potential to cause food spoilage as well as some that may be mycotoxigenic. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Introduction to the Microbiological Spoilage of Foods and Beverages

    Science.gov (United States)

    Sperber, William H.

    Though direct evidence of ancient food-handling practices is difficult to obtain and examine, it seems safe to assume that over the span of several million years, prehistoric humans struggled to maintain an adequate food supply. Their daily food needed to be hunted or harvested and consumed before it spoiled and became unfit to eat. Freshly killed animals, for example, could not have been kept for very long periods of time. Moreover, many early humans were nomadic, continually searching for food. We can imagine that, with an unreliable food supply, their lives must have often been literally "feast or famine." Yet, our ancestors gradually learned by accident, or by trial and error, simple techniques that could extend the storage time of their food (Block, 1991). Their brain capacity was similar to that of modern humans; therefore, some of them were likely early scientists and technologists. They would have learned that primitive cereal grains, nuts and berries, etc. could be stored in covered vessels to keep them dry and safer from mold spoilage. Animal products could be kept in cool places or dried and smoked over a fire, as the controlled use of fire by humans is thought to have begun about 400,000 years ago. Quite likely, naturally desiccated or fermented foods were also noticed and produced routinely to provide a more stable supply of edible food. Along with the development of agricultural practices for crop and animal production, the "simple" food-handling practices developed during the relatively countless millennia of prehistory paved the way for human civilizations.

  11. Modelling the effect of ethanol on growth rate of food spoilage moulds

    NARCIS (Netherlands)

    Dantigny, P.; Guilmart, A.; Radoi, F.; Bensoussan, M.; Zwietering, M.H.

    2005-01-01

    The effect of ethanol (E) on the radial growth rate (¿) of food spoilage moulds (Aspergillus candidus, Aspergillus flavus, Aspergillus niger, Cladosporium cladosporioides, Eurotium herbariorum, Mucor circinelloides, Mucor racemosus, Paecilomyces variotii, Penicillium chrysogenum, Penicillium

  12. Fungal volatiles as indicators of food and feeds spoilage.

    Science.gov (United States)

    Schnürer, J; Olsson, J; Börjesson, T

    1999-01-01

    Fungal growth leads to spoilage of food and animal feeds and to formation of mycotoxins and potentially allergenic spores. Fungi produce volatile compounds, during both primary and secondary metabolism, which can be used for detection and identification. Fungal volatiles from mainly Aspergillus, Fusarium, and Penicillium have been characterized with gas chromatography, mass spectrometry, and sensory analysis. Common volatiles are 2-methyl-1-propanol, 3-methyl-1-butanol, 1-octen-3-ol, 3-octanone, 3-methylfuran, ethyl acetate, and the malodorous 2-methyl-isoborneol and geosmin. Volatile sesquiterpenes can be used for taxonomic classification and species identification in Penicillium, as well as to indicate mycotoxin formation in Fusarium and Aspergillus. Developments in sensor technology have led to the construction of "electronic noses" (volatile compound mappers). Exposure of different nonspecific sensors to volatile compounds produces characteristic electrical signals. These are collected by a computer and processed by multivariate statistical methods or in an artificial neural network (ANN). Such systems can grade cereal grain with regard to presence of molds as efficiently as sensory panels evaluating grain odor. Volatile compound mapping can also be used to predict levels of ergosterol and fungal colony-forming units in grain. Further developments should make it possible to detect individual fungal species as well as the degree of mycotoxin contamination of food and animal feeds. Copyright 1999 Academic Press.

  13. Analysis of the inhibition of food spoilage yeasts by vanillin.

    Science.gov (United States)

    Fitzgerald, Daniel J; Stratford, Malcolm; Narbad, Arjan

    2003-09-01

    The antimicrobial potential of vanillin, the major component of vanilla flavour, was examined against the growth of three yeasts associated with food spoilage, Saccharomyces cerevisiae, Zygosaccharomyces bailii and Zygosaccharomyces rouxii. Minimum inhibitory concentration (MIC) values of 21, 20 and 13 mM vanillin were determined for the three yeast strains, respectively. The observed inhibition was found to be biostatic. During fermentation, the bioconversion of sub-MIC levels of vanillin in the culture medium was demonstrated. The major bioconversion product was identified as vanillyl alcohol, however low levels of vanillic acid were also detected. Neither the vanillyl alcohol nor the vanillic acid was found to be antagonistic to yeast cell growth. The results indicate the importance of the aldehyde moiety in the vanillin structure regarding its antimicrobial activity and that the bioconversion of vanillin could be advantageous for the yeasts, but only at levels below MIC. These bioconversion activities, presumably catalysed by non-specific dehydrogenases, were shown to be expressed constitutively. It was observed that increased vanillin concentrations inhibited its own bioconversion suggesting that the activity required intact cells with metabolic capacity.

  14. Antimicrobial activity of essential oil components against potential food spoilage microorganisms.

    Science.gov (United States)

    Klein, G; Rüben, C; Upmann, M

    2013-08-01

    The antimicrobial activity of six essential oil components against the potential food spoilage bacteria Aeromonas (A.) hydrophila, Escherichia (E.) coli, Brochothrix (B.) thermosphacta, and Pseudomonas (P.) fragi at single use and in combination with each other was investigated. At single use, the most effective oil components were thymol (bacteriostatic effect starting from 40 ppm, bactericidal effect with 100 ppm) and carvacrol (50 ppm/100 ppm), followed by linalool (180 ppm/720 ppm), α-pinene (400 ppm/no bactericidal effect), 1,8-cineol (1,400 ppm/2,800 ppm), and α-terpineol (600 ppm/no bactericidal effect). Antimicrobial effects occurred only at high, sensorial not acceptable concentrations. The most susceptible bacterium was A. hydrophila, followed by B. thermosphacta and E. coli. Most of the essential oil component combinations tested showed a higher antimicrobial effect than tested at single use. Antagonistic antimicrobial effects were observed particularly against B. thermosphacta, rarely against A. hydrophila. The results show that the concentration of at least one of the components necessary for an antibacterial effect is higher than sensorial acceptable. So the use of herbs with a high content of thymol, carvacrol, linalool, 1,8-cineol, α-pinene or α-terpineol alone or in combination must be weighted against sensorial quality.

  15. Microbial community analysis of food-spoilage bacteria in commercial custard creams using culture-dependent and independent methods.

    Science.gov (United States)

    Arakawa, K; Kawai, Y; Iioka, H; Tanioka, M; Nishimura, J; Kitazawa, H; Tsurumi, K; Saito, T

    2008-08-01

    Custard cream is made from highly nutritive raw materials such as milk and sugar and is easily spoiled by the multiplication of specific microbial contaminants or residents. However, this spoilage microbial community has not been studied. We determined the spoilage microbiota in commercial custard creams using culture-dependent and independent methods. Using the culture-dependent analysis with various agar media, 185 bacterial colonies and 43 eukaryal colonies were isolated from 7 commercial custard cream products. All bacterial isolates were morphologically, physiologically, and genetically identified as bacilli, staphylococci, lactic acid bacteria, and psychrotrophic gram-negative rods. Using culture-independent molecular analysis, the PCR-denaturing gradient gel electrophoresis technique, spoilage of the commercial custard creams was found to be caused by bacilli, staphylococci, lactic acid bacteria, psychrotrophic gram-negative rods, Anoxybacillus sp., Caurobacter sp., and Streptococcus sp. bacteria. The detected spoilage bacteria were the same species as previously detected in spoiled milk products and shown in other reports, suggesting that spoilage bacteria in a raw material easily grow in processed foods made from milk. We determined the spoilage microbial communities in commercial custard creams, and these are the first data concerning spoilage microbiota in nonfermented processed foods using a culture-independent analysis. Our study will be useful for the manufacture and safe preservation of dairy products because the first step toward safe food preservation by food manufacturers is to understand the spoilage microbiota in a target food to select optimal preservatives and to reduce the use of food additives.

  16. Amplicon sequencing for the quantification of spoilage microbiota in complex foods including bacterial spores

    NARCIS (Netherlands)

    Boer, de P.; Caspers, M.; Sanders, J.W.; Kemperman, R.; Wijman, J.; Lommerse, G.; Roeselers, G.; Montijn, R.; Abee, T.; Kort, R.

    2015-01-01

    Background
    Spoilage of food products is frequently caused by bacterial spores and lactic acid bacteria. Identification of these organisms by classic cultivation methods is limited by their ability to form colonies on nutrient agar plates. In this study, we adapted and optimized 16S rRNA amplicon

  17. Oxygen Requirements of the Food Spoilage Yeast Zygosaccharomyces bailii in Synthetic and Complex Media

    OpenAIRE

    Rodrigues, Fernando; Côrte-Real, Manuela; Leão, Cecília; van Dijken, Johannes P.; Pronk, Jack T.

    2001-01-01

    Most yeast species can ferment sugars to ethanol, but only a few can grow in the complete absence of oxygen. Oxygen availability might, therefore, be a key parameter in spoilage of food caused by fermentative yeasts. In this study, the oxygen requirement and regulation of alcoholic fermentation were studied in batch cultures of the spoilage yeast Zygosaccharomyces bailii at a constant pH, pH 3.0. In aerobic, glucose-grown cultures, Z. bailii exhibited aerobic alcoholic fermentation similar to...

  18. Genome sequence of the food spoilage Yeast Zygosaccharomyces bailii CLIB 213T.

    OpenAIRE

    Galeote, Virginie; Bigey, Frédéric; Devillers, Hugo; Neuvéglise, Cécile; Dequin, Sylvie

    2013-01-01

    The ascomycetous yeast Zygosaccharomyces bailii is one of the most problematic spoilage yeasts in food and beverage industries, due to its exceptional resistance to various stresses. A better understanding of the molecular mechanisms underlying these stress resistance phenotypes might help develop strategies to improve food quality. Thus, we determined and annotated the genome sequence of the strain Z. bailii CLIB 213(T) (= CBS 680).

  19. Genome Sequence of the Food Spoilage Yeast Zygosaccharomyces bailii CLIB 213T.

    Science.gov (United States)

    Galeote, Virginie; Bigey, Frédéric; Devillers, Hugo; Neuvéglise, Cécile; Dequin, Sylvie

    2013-08-22

    The ascomycetous yeast Zygosaccharomyces bailii is one of the most problematic spoilage yeasts in food and beverage industries, due to its exceptional resistance to various stresses. A better understanding of the molecular mechanisms underlying these stress resistance phenotypes might help develop strategies to improve food quality. Thus, we determined and annotated the genome sequence of the strain Z. bailii CLIB 213(T) (= CBS 680).

  20. Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage

    OpenAIRE

    Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Hélène Desmonts, Marie; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie

    2014-01-01

    The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most...

  1. In situ control of food spoilage fungus using Lactobacillus acidophilus NCDC 291.

    Science.gov (United States)

    Garcha, Seema; Natt, Navdeep Kaur

    2012-10-01

    A challenge for food industry today is to produce minimally processed food, without use of chemical preservatives and little compromise on nutritional status. Lactobacillus acidophilus NCDC 291 can be directly added to food where it enhances shelf life by competing with other microflora (both bacterial and fungal) for food and also by production of antimicrobial metabolites as bacteriocins. Comprehensive studies have demonstrated the in vitro activity of bacteriocins. However their role in preventing fresh food spoilage needs more elucidation. The present study was conducted to evaluate the efficacy of the whole cells of this organism as biopreservative agent against fungi. Four most commonly occurring spoilage fungi were isolated and were identified as Fusarium, Alternaria, Penicillium and Aspergillus. Growth of all of them was inhibited in in vitro studies, (approximately 33-43% decrease in mycelial dry weight basis between test and control). In situ biopreservation of Indian cheese and raw poultry meat was attempted and the colony count of Alternaria was significantly (p spoilage was not observed up to 6 days.

  2. Antimicrobial activity of Lactobacillus acidophilus against pathogenic and food spoilage microorganisms: A review

    Directory of Open Access Journals (Sweden)

    T. Dinev

    2017-03-01

    Full Text Available Abstract. The purpose of this review is to summarize the information regarding the antimicrobial activity of Lactobacillus acidophilus, an important species of lactic acid bacteria. Lactic acid bacteria are constituents of many beneficent for the consumer's health food products. They are considered potentially promising in the strategy to combat infections and prevent the growth of spoilage microorganisms, and also have antimutagenic, anticarcinogenic, hypolipidemic and hypocholesterolemic properties, improve the lactose metabolism, stimulate the immune system, etc. In the resent years Lactobacillus acidophilus is considered the main probiotic species in the intestinal tract of healthy humans and is widely used in functional dairy foods. It produces a variety of metabolic products with antimicrobial properties, including organic acids and bacteriocins, such as lactacins B and F, acidophilin, acidocin, acidophilucin, acidophilicin, which are active against many pathogenic and spoilage microorganisms - Escherichia coli (including Escherichi coli 0157:H7, Staphylococcus aureus, Pseudomonas aeruginosa, Listeria monocytogenes, Vibrio parahaemolyticus, Vibrio cholerae, Helicobacter pylori, Klebsiella, Salmonella, Shigella, Bacillus, Clostridium, Mucor, Aspergillus, Fusarium, Trichoderma and Candida spp., etc. Because of the above mentioned reasons Lactobacillus acidophilus could be used as an alternative therapeutic agent against infections caused by susceptible microorganisms. On the other hand Lactobacillus acidophilus based antimicrobial products (mainly bacteriocins and pure cultures could also be applied to food products to prevent the growth of spoilage microorganisms and food-borne pathogens. To better understand the mode of action and the spectrum of antifungal activity more clinical and laboratory studies of different Lactobacillus acidophilus strains are required.

  3. Factors Affecting Microbial Load and Profile of Potential Pathogens and Food Spoilage Bacteria from Household Kitchen Tables

    OpenAIRE

    Biranjia-Hurdoyal, Susheela; Latouche, Melissa Cathleen

    2016-01-01

    The aim was to study the bacterial load and isolate potential pathogens and food spoilage bacteria from kitchen tables, including preparation tables and dining tables. Methods. A total of 53 households gave their consent for participation. The samples were collected by swabbing over an area of 5?cm by 5?cm of the tables and processed for bacterial count which was read as colony forming units (CFU), followed by isolation and identification of potential pathogens and food spoilage bacteria. Res...

  4. Amplicon sequencing for the quantification of spoilage microbiota in complex foods including bacterial spores.

    Science.gov (United States)

    de Boer, Paulo; Caspers, Martien; Sanders, Jan-Willem; Kemperman, Robèr; Wijman, Janneke; Lommerse, Gijs; Roeselers, Guus; Montijn, Roy; Abee, Tjakko; Kort, Remco

    2015-01-01

    Spoilage of food products is frequently caused by bacterial spores and lactic acid bacteria. Identification of these organisms by classic cultivation methods is limited by their ability to form colonies on nutrient agar plates. In this study, we adapted and optimized 16S rRNA amplicon sequencing for quantification of bacterial spores in a canned food matrix and for monitoring the outgrowth of spoilage microbiota in a ready-to-eat food matrix. The detection limit of bar-coded 16S rRNA amplicon sequencing was determined for the number of bacterial spores in a canned food matrix. Analysis of samples from a canned food matrix spiked with a mixture of equinumerous spores from the thermophiles, Geobacillus stearothermophilus and Geobacillus thermoglucosidans, and the mesophiles, Bacillus sporothermodurans, Bacillus cereus, and Bacillus subtilis, led to the detection of these spores with an average limit of 2 × 10(2) spores ml(-1). The data were normalized by setting the number of sequences resulting from DNA of an inactivated bacterial species, present in the matrix at the same concentration in all samples, to a fixed value for quantitative sample-to-sample comparisons. The 16S rRNA amplicon sequencing method was also employed to monitor population dynamics in a ready-to-eat rice meal, incubated over a period of 12 days at 7 °C. The most predominant outgrowth was observed by the genera Leuconostoc, Bacillus, and Paenibacillus. Analysis of meals pre-treated with weak acids showed inhibition of outgrowth of these three genera. The specificity of the amplicon synthesis was improved by the design of oligonucleotides that minimize the amplification of 16S rRNA genes from chloroplasts originating from plant-based material present in the food. This study shows that the composition of complex spoilage populations, including bacterial spores, can be monitored in complex food matrices by bar-coded amplicon sequencing in a quantitative manner. In order to allow sample

  5. Adaptive ingredients against food spoilage in Japanese cuisine.

    Science.gov (United States)

    Ohtsubo, Yohsuke

    2009-12-01

    Billing and Sherman proposed the antimicrobial hypothesis to explain the worldwide spice use pattern. The present study explored whether two antimicrobial ingredients (i.e. spices and vinegar) are used in ways consistent with the antimicrobial hypothesis. Four specific predictions were tested: meat-based recipes would call for more spices/vinegar than vegetable-based recipes; summer recipes would call for more spices/vinegar than winter recipes; recipes in hotter regions would call for more spices/vinegar; and recipes including unheated ingredients would call for more spices/vinegar. Spice/vinegar use patterns were compiled from two types of traditional Japanese cookbooks. Dataset I included recipes provided by elderly Japanese housewives. Dataset II included recipes provided by experts in traditional Japanese foods. The analyses of Dataset I revealed that the vinegar use pattern conformed to the predictions. In contrast, analyses of Dataset II generally supported the predictions in terms of spices, but not vinegar.

  6. A mixed-species microarray for identification of food spoilage bacilli.

    Science.gov (United States)

    Caspers, Martien P M; Schuren, Frank H J; van Zuijlen, Andre C M; Brul, Stanley; Montijn, Roy C; Abee, Tjakko; Kort, Remco

    2011-04-01

    Failure of food preservation is frequently caused by thermostable spores of members of the Bacillaceae family, which show a wide spectrum of resistance to cleaning and preservation treatments. We constructed and validated a mixed-species genotyping array for 6 Bacillus species, including Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus sporothermodurans, Bacillus cereus and Bacillus coagulans, and 4 Geobacillus species, including Geobacillus stearothermophilus, Geobacillus thermocatenulatus, Geobacillus toebii and Geobacillus sp., in order to track food spoilage isolates from ingredient to product. The discriminating power of the array was evaluated with sets of 42 reference and 20 test strains. Bacterial isolates contain a within-species-conserved core genome comprising 68-88% of the entire genome and a non-conserved accessory genome comprising 7-22%. The majority of the core genome markers do not hybridise between species, thus they allow for efficient discrimination at the species level. The accessory genome array markers provide high-resolution discrimination at the level of individual isolates from a single species. In conclusion, the reported mixed-species microarray contains discriminating markers that allow rapid and cost-effective typing of Bacillus food spoilage bacteria in a wide variety of food products. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Antimicrobial effect of emulsion-encapsulated isoeugenol against biofilms of food pathogens and spoilage bacteria.

    Science.gov (United States)

    Krogsgård Nielsen, Christina; Kjems, Jørgen; Mygind, Tina; Snabe, Torben; Schwarz, Karin; Serfert, Yvonne; Meyer, Rikke Louise

    2017-02-02

    Food-related biofilms can cause food-borne illnesses and spoilage, both of which are problems on a global level. Essential oils are compounds derived from plant material that have a potential to be used in natural food preservation in the future since they are natural antimicrobials. Bacterial biofilms are particularly resilient towards biocides, and preservatives that effectively eradicate biofilms are therefore needed. In this study, we test the antibacterial properties of emulsion-encapsulated and unencapsulated isoeugenol against biofilms of Lis. monocytogenes, S. aureus, P. fluorescens and Leu. mesenteroides in tryptic soy broth and carrot juice. We show that emulsion encapsulation enhances the antimicrobial properties of isoeugenol against biofilms in media but not in carrot juice. Some of the isoeugenol emulsions were coated with chitosan, and treatment of biofilms with these emulsions disrupted the biofilm structure. Furthermore, we show that addition of the surfactant Tween 80, which is commonly used to disperse oils in food, hampers the antibacterial properties of isoeugenol. This finding highlights that common food additives, such as surfactants, may have an adverse effect on the antibacterial activity of preservatives. Isoeugenol is a promising candidate as a future food preservative because it works almost equally well against planktonic bacteria and biofilms. Emulsion encapsulation has potential benefits for the efficacy of isoeugenol, but the effect of encapsulation depends on the properties of food matrix in which isoeugenol is to be applied. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Oxygen requirements of the food spoilage yeast Zygosaccharomyces bailii in synthetic and complex media.

    Science.gov (United States)

    Rodrigues, F; Côrte-Real, M; Leão, C; van Dijken, J P; Pronk, J T

    2001-05-01

    Most yeast species can ferment sugars to ethanol, but only a few can grow in the complete absence of oxygen. Oxygen availability might, therefore, be a key parameter in spoilage of food caused by fermentative yeasts. In this study, the oxygen requirement and regulation of alcoholic fermentation were studied in batch cultures of the spoilage yeast Zygosaccharomyces bailii at a constant pH, pH 3.0. In aerobic, glucose-grown cultures, Z. bailii exhibited aerobic alcoholic fermentation similar to that of Saccharomyces cerevisiae and other Crabtree-positive yeasts. In anaerobic fermentor cultures grown on a synthetic medium supplemented with glucose, Tween 80, and ergosterol, S. cerevisiae exhibited rapid exponential growth. Growth of Z. bailii under these conditions was extremely slow and linear. These linear growth kinetics indicate that cell proliferation of Z. bailii in the anaerobic fermentors was limited by a constant, low rate of oxygen leakage into the system. Similar results were obtained with the facultatively fermentative yeast Candida utilis. When the same experimental setup was used for anaerobic cultivation, in complex YPD medium, Z. bailii exhibited exponential growth and vigorous fermentation, indicating that a nutritional requirement for anaerobic growth was met by complex-medium components. Our results demonstrate that restriction of oxygen entry into foods and beverages, which are rich in nutrients, is not a promising strategy for preventing growth and gas formation by Z. bailii. In contrast to the growth of Z. bailii, anaerobic growth of S. cerevisiae on complex YPD medium was much slower than growth in synthetic medium, which probably reflected the superior tolerance of the former yeast to organic acids at low pH.

  9. Oxygen Requirements of the Food Spoilage Yeast Zygosaccharomyces bailii in Synthetic and Complex Media

    Science.gov (United States)

    Rodrigues, Fernando; Côrte-Real, Manuela; Leão, Cecília; van Dijken, Johannes P.; Pronk, Jack T.

    2001-01-01

    Most yeast species can ferment sugars to ethanol, but only a few can grow in the complete absence of oxygen. Oxygen availability might, therefore, be a key parameter in spoilage of food caused by fermentative yeasts. In this study, the oxygen requirement and regulation of alcoholic fermentation were studied in batch cultures of the spoilage yeast Zygosaccharomyces bailii at a constant pH, pH 3.0. In aerobic, glucose-grown cultures, Z. bailii exhibited aerobic alcoholic fermentation similar to that of Saccharomyces cerevisiae and other Crabtree-positive yeasts. In anaerobic fermentor cultures grown on a synthetic medium supplemented with glucose, Tween 80, and ergosterol, S. cerevisiae exhibited rapid exponential growth. Growth of Z. bailii under these conditions was extremely slow and linear. These linear growth kinetics indicate that cell proliferation of Z. bailii in the anaerobic fermentors was limited by a constant, low rate of oxygen leakage into the system. Similar results were obtained with the facultatively fermentative yeast Candida utilis. When the same experimental setup was used for anaerobic cultivation, in complex YPD medium, Z. bailii exhibited exponential growth and vigorous fermentation, indicating that a nutritional requirement for anaerobic growth was met by complex-medium components. Our results demonstrate that restriction of oxygen entry into foods and beverages, which are rich in nutrients, is not a promising strategy for preventing growth and gas formation by Z. bailii. In contrast to the growth of Z. bailii, anaerobic growth of S. cerevisiae on complex YPD medium was much slower than growth in synthetic medium, which probably reflected the superior tolerance of the former yeast to organic acids at low pH. PMID:11319090

  10. Bioactive packaging using antioxidant extracts for the prevention of microbial food-spoilage.

    Science.gov (United States)

    Moreira, Diana; Gullón, Beatriz; Gullón, Patricia; Gomes, Ana; Tavaria, Freni

    2016-07-13

    Bioactive food packaging is an innovative approach for the prevention of the growth of food-spoilage microorganisms. Four active extracts from agroindustrial subproducts (Eucalyptus wood, almond shells, corn cobs and grape pomace) with demonstrated antioxidant activity have been investigated for bestowing antimicrobial activity to bioactive packaging. To carry out this evaluation, the antioxidant extracts were tested against five food pathogenic bacteria, namely, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus and Salmonella spp. The results obtained showed that all the tested extracts inhibited the growth of all five pathogenic bacteria. From the analysis of the minimal bactericidal concentrations (MBCs), the Eucalyptus wood extract was the most active, being necessary only 2% (v/v) to inhibit Pseudomonas aeruginosa, Listeria monocytogenes, and Staphylococcus aureus, whereas almond shells extract were less active requiring 4% (w/v) to inhibit the growth of Escherichia coli and Pseudomonas aeruginosa and the extract from corn cobs was bactericidal against Escherichia coli and Staphylococcus aureus at a concentration of 4% (w/v). After checking their antimicrobial activity, the antioxidant extracts have been incorporated into sodium alginate films and the maintenance of their antimicrobial properties was confirmed. This work showed that the antioxidant extracts from agroindustrial byproducts exhibited antimicrobial activity and were suitable for incorporation into edible films that could be used in bioactive packaging systems.

  11. Synergized antimicrobial activity of eugenol incorporated polyhydroxybutyrate films against food spoilage microorganisms in conjunction with pediocin.

    Science.gov (United States)

    Narayanan, Aarthi; Neera; Mallesha; Ramana, Karna Venkata

    2013-07-01

    Biopolymers and biopreservatives produced by microorganisms play an essential role in food technology. Polyhydroxyalkanoates and bacteriocins produced by bacteria are promising components to safeguard the environment and for food preservation applications. Polyhydroxybutyrate (PHB)-based antimicrobial films were prepared incorporating eugenol, from 10 to 200 μg/g of PHB. The films were evaluated for antimicrobial activity against foodborne pathogens, spoilage bacteria, and fungi such as Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, Aspergillus flavus, Aspergillus niger, Penicillium sp., and Rhizopus sp. The synergistic antimicrobial activity of the films in the presence of crude pediocin was also investigated. The broth system containing pediocin (soluble form) as well as antimicrobial PHB film demonstrated an extended lag phase and a significant growth reduction at the end of 24 h against the bacteria. Crude pediocin alone could not elicit antifungal activity, while inhibition of growth and sporulation were observed in the presence of antimicrobial PHB film containing eugenol (80 μg/g) until 7 days in the case of molds, i.e., A. niger, A. flavus, Penicillium sp., and Rhizopus sp. in potato dextrose broth. In the present study, we identified that use of pediocin containing broth in conjunction with eugenol incorporated PHB film could function in synergized form, providing effective hurdle toward food contaminating microorganisms. Furthermore, tensile strength, percent crystallinity, melting point, percent elongation to break, glass transition temperature, and seal strength of the PHB film with and without eugenol incorporation were investigated. The migration of eugenol on exposure to different liquid food simulants was also analyzed using Fourier transform infrared spectroscopy. The study is expected to provide applications for pediocin in conjunction with eugenol containing PHB film to enhance the shelf life of foods in the

  12. Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage.

    Science.gov (United States)

    Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Desmonts, Marie Hélène; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

    2015-05-01

    The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota.

  13. Origin and ecological selection of core and food-specific bacterial communities associated with meat and seafood spoilage

    Science.gov (United States)

    Chaillou, Stéphane; Chaulot-Talmon, Aurélie; Caekebeke, Hélène; Cardinal, Mireille; Christieans, Souad; Denis, Catherine; Hélène Desmonts, Marie; Dousset, Xavier; Feurer, Carole; Hamon, Erwann; Joffraud, Jean-Jacques; La Carbona, Stéphanie; Leroi, Françoise; Leroy, Sabine; Lorre, Sylvie; Macé, Sabrina; Pilet, Marie-France; Prévost, Hervé; Rivollier, Marina; Roux, Dephine; Talon, Régine; Zagorec, Monique; Champomier-Vergès, Marie-Christine

    2015-01-01

    The microbial spoilage of meat and seafood products with short shelf lives is responsible for a significant amount of food waste. Food spoilage is a very heterogeneous process, involving the growth of various, poorly characterized bacterial communities. In this study, we conducted 16S ribosomal RNA gene pyrosequencing on 160 samples of fresh and spoiled foods to comparatively explore the bacterial communities associated with four meat products and four seafood products that are among the most consumed food items in Europe. We show that fresh products are contaminated in part by a microbiota similar to that found on the skin and in the gut of animals. However, this animal-derived microbiota was less prevalent and less abundant than a core microbiota, psychrotrophic in nature, mainly originated from the environment (water reservoirs). We clearly show that this core community found on meat and seafood products is the main reservoir of spoilage bacteria. We also show that storage conditions exert strong selective pressure on the initial microbiota: alpha diversity in fresh samples was 189±58 operational taxonomic units (OTUs) but dropped to 27±12 OTUs in spoiled samples. The OTU assemblage associated with spoilage was shaped by low storage temperatures, packaging and the nutritional value of the food matrix itself. These factors presumably act in tandem without any hierarchical pattern. Most notably, we were also able to identify putative new clades of dominant, previously undescribed bacteria occurring on spoiled seafood, a finding that emphasizes the importance of using culture-independent methods when studying food microbiota. PMID:25333463

  14. Factors Affecting Microbial Load and Profile of Potential Pathogens and Food Spoilage Bacteria from Household Kitchen Tables.

    Science.gov (United States)

    Biranjia-Hurdoyal, Susheela; Latouche, Melissa Cathleen

    2016-01-01

    The aim was to study the bacterial load and isolate potential pathogens and food spoilage bacteria from kitchen tables, including preparation tables and dining tables. Methods. A total of 53 households gave their consent for participation. The samples were collected by swabbing over an area of 5 cm by 5 cm of the tables and processed for bacterial count which was read as colony forming units (CFU), followed by isolation and identification of potential pathogens and food spoilage bacteria. Result. Knowledge about hygiene was not always put into practice. Coliforms, Enterococcus spp., Pseudomonas spp., Proteus spp., and S. aureus were detected from both dining and preparation tables. The mean CFU and presence of potential pathogens were significantly affected by the hygienic practices of the main food handler of the house, materials of kitchen tables, use of plastic covers, time of sample collection, use of multipurpose sponges/towels for cleaning, and the use of preparation tables as chopping boards (p food spoilage bacteria causing foodborne diseases. Lack of hygiene was confirmed by presence of coliforms, S. aureus, and Enterococcus spp. The use of plastic covers, multipurpose sponges, and towels should be discouraged.

  15. Factors Affecting Microbial Load and Profile of Potential Pathogens and Food Spoilage Bacteria from Household Kitchen Tables

    Directory of Open Access Journals (Sweden)

    Susheela Biranjia-Hurdoyal

    2016-01-01

    Full Text Available The aim was to study the bacterial load and isolate potential pathogens and food spoilage bacteria from kitchen tables, including preparation tables and dining tables. Methods. A total of 53 households gave their consent for participation. The samples were collected by swabbing over an area of 5 cm by 5 cm of the tables and processed for bacterial count which was read as colony forming units (CFU, followed by isolation and identification of potential pathogens and food spoilage bacteria. Result. Knowledge about hygiene was not always put into practice. Coliforms, Enterococcus spp., Pseudomonas spp., Proteus spp., and S. aureus were detected from both dining and preparation tables. The mean CFU and presence of potential pathogens were significantly affected by the hygienic practices of the main food handler of the house, materials of kitchen tables, use of plastic covers, time of sample collection, use of multipurpose sponges/towels for cleaning, and the use of preparation tables as chopping boards (p<0.05. Conclusion. Kitchen tables could be very important source of potential pathogens and food spoilage bacteria causing foodborne diseases. Lack of hygiene was confirmed by presence of coliforms, S. aureus, and Enterococcus spp. The use of plastic covers, multipurpose sponges, and towels should be discouraged.

  16. Global overview of the risk linked to the Bacillus cereus group in the egg product industry: identification of food safety and food spoilage markers.

    Science.gov (United States)

    Techer, C; Baron, F; Delbrassinne, L; Belaïd, R; Brunet, N; Gillard, A; Gonnet, F; Cochet, M-F; Grosset, N; Gautier, M; Andjelkovic, M; Lechevalier, V; Jan, S

    2014-05-01

    To evaluate the food safety and spoilage risks associated with psychrotrophic Bacillus cereus group bacteria for the egg product industry and to search for relevant risk markers. A collection of 68 psychrotrophic B. cereus group isolates, coming from pasteurized liquid whole egg products, was analysed through a principal component analysis (PCA) regarding their spoilage and food safety risk potentials. The principal component analysis showed a clear differentiation between two groups within the collection, one half of the isolates representing a safety risk and the other half a spoilage risk. Relevant risk markers were highlighted by PCA, that is (i) for the food safety risk, the presence of the specific 16S rDNA-1m genetic signature and the ability to grow at 43°C on solid medium and (ii) for the spoilage risk, the presence of the cspA genetic signature. This work represents a first step in the development of new diagnostic technologies for the assessment of the microbiological quality of foods likely to be contaminated with psychrotrophic B. cereus group bacteria. © 2014 The Society for Applied Microbiology.

  17. Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria

    Science.gov (United States)

    Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

    2014-01-01

    This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products. PMID:25473498

  18. Antimicrobial activities of commercial essential oils and their components against food-borne pathogens and food spoilage bacteria.

    Science.gov (United States)

    Mith, Hasika; Duré, Rémi; Delcenserie, Véronique; Zhiri, Abdesselam; Daube, Georges; Clinquart, Antoine

    2014-07-01

    This study was undertaken to determine the in vitro antimicrobial activities of 15 commercial essential oils and their main components in order to pre-select candidates for potential application in highly perishable food preservation. The antibacterial effects against food-borne pathogenic bacteria (Listeria monocytogenes, Salmonella Typhimurium, and enterohemorrhagic Escherichia coli O157:H7) and food spoilage bacteria (Brochothrix thermosphacta and Pseudomonas fluorescens) were tested using paper disk diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations. Most of the tested essential oils exhibited antimicrobial activity against all tested bacteria, except galangal oil. The essential oils of cinnamon, oregano, and thyme showed strong antimicrobial activities with MIC ≥ 0.125 μL/mL and MBC ≥ 0.25 μL/mL. Among tested bacteria, P. fluorescens was the most resistant to selected essential oils with MICs and MBCs of 1 μL/mL. The results suggest that the activity of the essential oils of cinnamon, oregano, thyme, and clove can be attributed to the existence mostly of cinnamaldehyde, carvacrol, thymol, and eugenol, which appear to possess similar activities against all the tested bacteria. These materials could be served as an important natural alternative to prevent bacterial growth in food products.

  19. The emulsifying effect of biosurfactants produced by food spoilage organisms in Nigeria

    Directory of Open Access Journals (Sweden)

    Christianah O. Ogunmola

    2016-04-01

    Full Text Available Food spoilage organisms were isolated using standard procedures on Nutrient Agar, Cetrimide Agar and Pseudomonas Agar Base (supplemented with CFC. The samples were categorized as animal products (raw fish, egg, raw chicken, corned beef, pasteurized milk and plant products (vegetable salad, water leaf (Talinium triangulare, boiled rice, tomatoes and pumpkin leaf (Teifairia occidentalis.They were characterised as Pseudomonas putida, Pseudomonas aeruginosa, Pseudomonas stutzeri, Burkholderia pseudomallei, Serratia rubidaea, Corynebacterium pilosum, Bacillus subtilis, Bacillus mycoides, Bacillus laterosporus, Bacillus laterosporus, Serratia marcescens, Bacillus cereus, Bacillus macerans, Alcaligenes faecalis and Alcaligenes eutrophus. Preliminary screening for biosurfactant production was done using red blood haemolysis test and confirmed by slide test, drop collapse and oil spreading assay. The biosurfactant produced was purified using acetone and the composition determined initially using Molisch’s test, thin layer chromatography and gas chromatography mass spectrometry. The components were found to be ethanol, amino acids, butoxyacetic acid, hexadecanoic acid, oleic acid, lauryl peroxide, octadecanoic acid and phthalic acid. The producing organisms grew readily on several hydrocarbons such as crude oil, diesel oil and aviation fuel when used as sole carbon sources.  The purified biosurfactants produced were able to cause emulsification of kerosene (19.71-27.14% as well as vegetable oil (16.91-28.12% based on the emulsification index. This result suggests that the isolates can be an asset and further work can exploit their optimal potential in industries.

  20. Identification of food and beverage spoilage yeasts from DNA sequence analyses.

    Science.gov (United States)

    Kurtzman, Cletus P

    2015-11-20

    Detection, identification and classification of yeasts have undergone major changes in the last decade and a half following application of gene sequence analyses and genome comparisons. Development of a database (barcode) of easily determined DNA sequences from domains 1 and 2 (D1/D2) of the nuclear large subunit rRNA gene and from ITS now permits many laboratories to identify species quickly and accurately, thus replacing the laborious and often inaccurate phenotypic tests previously used. Phylogenetic analysis of gene sequences has resulted in a major revision of yeast systematics resulting in redefinition of nearly all genera. This new understanding of species relationships has prompted a change of rules for naming and classifying yeasts and other fungi, and these new rules are presented in the recently implemented International Code of Nomenclature for algae, fungi, and plants (Melbourne Code). The use of molecular methods for species identification and the impact of Code changes on classification will be discussed, especially in the context of food and beverage spoilage yeasts. Published by Elsevier B.V.

  1. Design of an experimental viscoelastic food model system for studying Zygosaccharomyces bailii spoilage in acidic sauces.

    Science.gov (United States)

    Mertens, L; Geeraerd, A H; Dang, T D T; Vermeulen, A; Serneels, K; Van Derlinden, E; Cappuyns, A M; Moldenaers, P; Debevere, J; Devlieghere, F; Van Impe, J F

    2009-11-01

    Within the field of predictive microbiology, the number of studies that quantify the effect of food structure on microbial behavior is very limited. This is mainly due to impracticalities related to the use of a nonliquid growth medium. In this study, an experimental food model system for studying yeast spoilage in acid sauces was developed by selecting a suitable thickening/gelling agent. In a first step, a variety of thickening/gelling agents was screened, with respect to the main physicochemical (pH, water activity, and acetic acid and sugar concentrations) and rheological (weak gel viscoelastic behavior and presence of a yield stress) characteristics of acid sauces. Second, the rheological behavior of the selected thickening/gelling agent, Carbopol 980, was extensively studied within the following range of conditions: pH 4.0 to 5.0, acetic acid concentration of 0 to 1.0% (vol/vol), glycerol concentration of 0 to 15% (wt/vol), and Carbopol concentration of 1.0 to 1.5% (wt/vol). Finally, the applicability of the model system was illustrated by performing growth experiments in microtiter plates for Zygosaccharomyces bailii at 0, 0.5, 1.0, and 1.5% (wt/vol) Carbopol, 5% (wt/vol) glycerol, 0% (vol/vol) acetic acid, and pH 5.0. A shift from planktonic growth to growth in colonies was observed when the Carbopol concentration increased from 0.5 to 1.0%. The applicability of the model system was illustrated by estimating mu(max) at 0.5% Carbopol from absorbance detection times.

  2. Design of an Experimental Viscoelastic Food Model System for Studying Zygosaccharomyces bailii Spoilage in Acidic Sauces▿

    Science.gov (United States)

    Mertens, L.; Geeraerd, A. H.; Dang, T. D. T.; Vermeulen, A.; Serneels, K.; Van Derlinden, E.; Cappuyns, A. M.; Moldenaers, P.; Debevere, J.; Devlieghere, F.; Van Impe, J. F.

    2009-01-01

    Within the field of predictive microbiology, the number of studies that quantify the effect of food structure on microbial behavior is very limited. This is mainly due to impracticalities related to the use of a nonliquid growth medium. In this study, an experimental food model system for studying yeast spoilage in acid sauces was developed by selecting a suitable thickening/gelling agent. In a first step, a variety of thickening/gelling agents was screened, with respect to the main physicochemical (pH, water activity, and acetic acid and sugar concentrations) and rheological (weak gel viscoelastic behavior and presence of a yield stress) characteristics of acid sauces. Second, the rheological behavior of the selected thickening/gelling agent, Carbopol 980, was extensively studied within the following range of conditions: pH 4.0 to 5.0, acetic acid concentration of 0 to 1.0% (vol/vol), glycerol concentration of 0 to 15% (wt/vol), and Carbopol concentration of 1.0 to 1.5% (wt/vol). Finally, the applicability of the model system was illustrated by performing growth experiments in microtiter plates for Zygosaccharomyces bailii at 0, 0.5, 1.0, and 1.5% (wt/vol) Carbopol, 5% (wt/vol) glycerol, 0% (vol/vol) acetic acid, and pH 5.0. A shift from planktonic growth to growth in colonies was observed when the Carbopol concentration increased from 0.5 to 1.0%. The applicability of the model system was illustrated by estimating μmax at 0.5% Carbopol from absorbance detection times. PMID:19783742

  3. Comparison of antibacterial effect of seven 1-monoglycerides on food-borne pathogens or spoilage bacteria

    Directory of Open Access Journals (Sweden)

    Leona Buňková

    2011-01-01

    Full Text Available The aim of this study was to compare under the same conditions in vitro the inhibitory effects of seven 1-monoglycerides (MAG containing fatty acids with a medium chain on ten strains of food-borne pathogens or spoilage gram-positive and gram-negative bacteria (Bacillus cereus, Bacillus subtilis, Enterococcus faecalis, Micrococcus luteus, Staphylococcus aureus, Citrobacter freundii, Escherichia coli, Proteus mirabilis, Salmonella enterica ser. Enteritidis and Pseudomonas aeruginosa and on their growth indicatos. The inhibitory effect of MAGs (monocaprylin, monocaprin, monolaurin, monomyristin, monopalmitin, MAG of undecanoic and 10-undecenoic acids at a concentration of 25 – 1500 mg·l-1 was observed. Growth of bacteria in the presence of MAG was studied by means of optical density of bacteria for 24 h. The data were modelled through a Gompertz equation and the lag-time, the maximum specific growth rate and the maximal value reached were calculated. MAGs inhibited mainly the growth of gram-positive bacteria, which was shown by the extended lag-time, decrease in specific growth rate and decrease in cell density. Inhibitory effects of tested MAGs could be ranked from point of view of the minimum inhibitory concentration: MAG-C12:0 > MAG-C11:0 > MAG-C10:0 > MAG-C14:0 > MAG-C11:1 > MAG-C8:0 > MAG-C16:0. In vitro, no significant inhibitory effects of 1-monoglycerides, with the exception of the highest concentrations applied, on the growth of gram-negative bacteria were detected. The main contribution of this study is to compare the effects of several MAG containing fatty acids with a medium chain under the same conditions on the growth indicators of bacteria.

  4. Microbiological Spoilage of Cereal Products

    Science.gov (United States)

    Cook, Frederick K.; Johnson, Billie L.

    A wide range of cereal products, including bakery items, refrigerated dough, fresh pasta products, dried cereal products, snack foods, and bakery mixes, are manufactured for food consumption. These products are subject to physical, chemical, and microbiological spoilage that affects the taste, aroma, leavening, appearance, and overall quality of the end consumer product. Microorganisms are ubiquitous in nature and have the potential for causing food spoilage and foodborne disease. However, compared to other categories of food products, bakery products rarely cause food poisoning. The heat that is applied during baking or frying usually eliminates pathogenic and spoilage microorganisms, and low moisture contributes to product stability. Nevertheless, microbiological spoilage of these products occurs, resulting in substantial economic losses.

  5. Potassium transport at the plasma membrane of the food spoilage yeast Zygosaccharomyces bailii.

    Science.gov (United States)

    Demidchik, Vadim; Macpherson, Neil; Davies, Julia M

    2005-01-15

    Zygosaccharomyces bailii is a commercially important spoilage yeast capable of growth at low pH in the presence of weak organic acid preservatives, such as benzoic acid. A patch-clamp electrophysiological analysis of plasma membrane K+ transport revealed a high conductance pathway for low-affinity K+ uptake. In contrast to the equivalent K+ transporter in Saccharomyces cerevisiae, this system remained operative at low extracellular pH and may therefore facilitate K+ uptake in K(+)-rich and acidic beverages. Benzoate inhibited growth, increased intracellular K+ content, yet decreased the magnitude of the K+ uptake conductance; specifically, the hyperpolarization-activated inwardly-rectifying component was reduced. It is proposed that this adaptation helps maintain a hyperpolarized membrane voltage to effect continued ATPase-mediated H+ extrusion and so combat preservative-induced cytosolic acidosis. Again in contrast to S. cerevisiae, the K+ conductance was relatively insensitive to increased extracellular Ca2+. Paradoxically (and unlike S. cerevisiae) increasing extracellular Ca2+ inhibited growth, suggesting a simple expedient to limit spoilage by Z. bailii.

  6. Draft genome sequence and annotation of Lactobacillus acetotolerans BM-LA14527, a beer-spoilage bacteria.

    Science.gov (United States)

    Liu, Junyan; Li, Lin; Peters, Brian M; Li, Bing; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

    2016-09-01

    Lactobacillus acetotolerans is a hard-to-culture beer-spoilage bacterium capable of entering into the viable putative nonculturable (VPNC) state. As part of an initial strategy to investigate the phenotypic behavior of L. acetotolerans, draft genome sequencing was performed. Results demonstrated a total of 1824 predicted annotated genes, with several potential VPNC- and beer-spoilage-associated genes identified. Importantly, this is the first genome sequence of L. acetotolerans as beer-spoilage bacteria and it may aid in further analysis of L. acetotolerans and other beer-spoilage bacteria, with direct implications for food safety control in the beer brewing industry. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Nanoemulsion of orange oil with non ionic surfactant produced emulsion using ultrasonication technique: evaluating against food spoilage yeast

    Science.gov (United States)

    Sugumar, Saranya; Singh, Sanjay; Mukherjee, Amitava; Chandrasekaran, N.

    2016-01-01

    In recent years, food industries have shown great interest in developing nanoemulsion (NE) using essential oils (EOs) to prevent food spoilage caused by microorganisms. The hydrophobic properties of EOs have lead to reduced solubilization effect of food, which in turn, created a negative impact on the quality of food and its antimicrobial efficacy. Focusing this issue, we attempted a unique NE preparation using orange oil, Tween 80 (organic phase) and water (aqueous phase) by sonication technique. Based on thermodynamic stability studies, the effective diameter was reported to be in the size range from 20 to 30 nm. Saccharomyces cerevisiae was used in testing the anti-yeast effect. Their activity was studied in both growth medium and apple juice. The minimum inhibitory concentration of this NE was determined using broth dilution method. At 2 μl/ml, orange oil NE demonstrated inhibition of tested microorganisms. The kinetics of killing curve, have shown that the NE treated cells had lost its viability within 30 min of interaction. Also, SEM image revealed that the treated cells became distorted in comparison to their control cells. NE treated apple juice showed complete loss of viability even on dilution as compared to their controls.

  8. In situ control of food spoilage fungus using Lactobacillus acidophilus NCDC 291

    OpenAIRE

    Garcha, Seema; Natt, Navdeep Kaur

    2011-01-01

    A challenge for food industry today is to produce minimally processed food, without use of chemical preservatives and little compromise on nutritional status. Lactobacillus acidophilus NCDC 291 can be directly added to food where it enhances shelf life by competing with other microflora (both bacterial and fungal) for food and also by production of antimicrobial metabolites as bacteriocins. Comprehensive studies have demonstrated the in vitro activity of bacteriocins. However their role in pr...

  9. Development Of Polyaniline As A Sensor For Food Quality And Spoilage Detection

    OpenAIRE

    Hobday, Duncan Stuart

    2009-01-01

    This thesis describes the research that has been completed for the application of polyaniline as a food quality indicator. It has been reported by WRAP (Waste and Resources Action Programme) that in the UK alone, a third of all purchased food items are thrown away regardless of the quality or condition. It has also been reported by DEFRA (Department for Environment Food and Rural Affairs) that the food manufacturing and processing industry is one of the UK’s largest producers of land fil...

  10. Cost-intensive irradiation could cut SA's R500 m/year food spoilage

    International Nuclear Information System (INIS)

    Groves, D.

    1979-01-01

    The Republic of South Africa is today the world's sixth biggest food exporter, a position it needs to maintain, in the face of its own fast-growing population and increasing demand for quality foodstuffs. Increasing food production will be limited in the long run by the availability of arable soil - so minimissing food losses seems the ultimate answer, and the irradiation process offers just that. What distributors, producers, exporters and retailers need to know in detail now is how much it will cost for particular applications in various circumstances. Techno-economic feasibility studies are essential

  11. Antifungal activity of some marine organisms from India, against food spoilage Aspergillus strains

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosale, S.H.; Jagtap, T.G.; Naik, C.G.

    Crude aqueous methanol extracts obtained from 31 species of various marine organisms (including floral and faunal), were screened for their antifungal activity against food poisoning strains of Aspergillus. Seventeen species exhibited mild (+ = zone...

  12. Application of Electronic Noses for Disease Diagnosis and Food Spoilage Detection

    Directory of Open Access Journals (Sweden)

    Paolo Di Francesco

    2006-11-01

    Full Text Available Over the last twenty years, newly developed chemical sensor systems (socalled“electronic noses" have odour analyses made possible. This paper describes theapplications of these systems for microbial detection in different fields such as medicineand the food industry, where fast detection methods are essential for appropriatemanagement of health care. Several groups have employed different electronic noses forclassification and quantification of bacteria and fungi to obtain accurate medicaldiagnosis and food quality control. So far, detection and identification of bacterial andfungal volatiles have been achieved by use of e-noses offering different correctclassification percentages. The present review includes examples of bacterial and fungalspecies producing volatile compounds and correlated to infectious diseases or fooddeterioration. The results suggest the possibility of using this new technology both inmedical diagnostics and in food control management.

  13. A mixed-species microarray for identification of food spoilage bacilli

    NARCIS (Netherlands)

    Caspers, M.P.M.; Schuren, F.H.J.; van Zuijlen, A.C.M.; Brul, S.; Montijn, R.C.; Abee, T.; Kort, R.

    2011-01-01

    Failure of food preservation is frequently caused by thermostable spores of members of the Bacillaceae family, which show a wide spectrum of resistance to cleaning and preservation treatments. We constructed and validated a mixed-species genotyping array for 6 Bacillus species, including Bacillus

  14. A mixed-species microarray for identification of food spoilage bacilli

    NARCIS (Netherlands)

    Caspers, Martien P M; Schuren, Frank H J; van Zuijlen, Andre C M; Brul, Stanley; Montijn, Roy C; Abee, Tjakko; Kort, Remco

    Failure of food preservation is frequently caused by thermostable spores of members of the Bacillaceae family, which show a wide spectrum of resistance to cleaning and preservation treatments. We constructed and validated a mixed-species genotyping array for 6 Bacillus species, including Bacillus

  15. Application of Electronic Noses for Disease Diagnosis and Food Spoilage Detection

    OpenAIRE

    Casalinuovo, Ida A.; Di Pierro, Donato; Coletta, Massimiliano; Di Francesco, Paolo

    2006-01-01

    Over the last twenty years, newly developed chemical sensor systems (so-called “electronic noses”) have odour analyses made possible. This paper describes the applications of these systems for microbial detection in different fields such as medicine and the food industry, where fast detection methods are essential for appropriate management of health care. Several groups have employed different electronic noses for classification and quantification of bacteria and fungi to obtain accurate med...

  16. The antimicrobial efficacy and structure activity relationship of novel carbohydrate fatty acid derivatives against Listeria spp. and food spoilage microorganisms.

    Science.gov (United States)

    Nobmann, Patricia; Smith, Aoife; Dunne, Julie; Henehan, Gary; Bourke, Paula

    2009-01-15

    Novel mono-substituted carbohydrate fatty acid (CFA) esters and ethers were investigated for their antibacterial activity against a range of pathogenic and spoilage bacteria focussing on Listeria monocytogenes. Carbohydrate derivatives with structural differences enable comparative studies on the structure/activity relationship for antimicrobial efficacy and mechanism of action. The antimicrobial efficacy of the synthesized compounds was compared with commercially available compounds such as monolaurin and monocaprylin, as well as the pure free fatty acids, lauric acid and caprylic acid, which have proven antimicrobial activity. Compound efficacy was compared using an absorbance based broth microdilution assay to determine the minimum inhibitory concentration (MIC), increase in lag phase and decrease in maximum growth rate. Among the carbohydrate derivatives synthesized, lauric ether of methyl alpha-d-glucopyranoside and lauric ester of methyl alpha-d-mannopyranoside showed the highest growth-inhibitory effect with MIC values of 0.04 mM, comparable to monolaurin. CFA derivatives were generally more active against Gram positive bacteria than Gram negative bacteria. The analysis of both ester and ether fatty acid derivatives of the same carbohydrate, in tandem with alpha and beta configuration of the carbohydrate moiety suggest that the carbohydrate moiety is involved in the antimicrobial activity of the fatty acid derivatives and that the nature of the bond also has a significant effect on efficacy, which requires further investigation. This class of CFA derivatives has great potential for developing antibacterial agents relevant to the food industry, particularly for control of Listeria or other Gram-positive pathogens.

  17. Myrtus communis essential oil: chemical composition and antimicrobial activities against food spoilage pathogens.

    Science.gov (United States)

    Ben Hsouna, Anis; Hamdi, Naceur; Miladi, Ramzi; Abdelkafi, Slim

    2014-04-01

    Myrtus communis is a typical plant of the Mediterranean area, which is mainly used as animal and human food and, in folk medicine, for treating some disorders. In the present study, we evaluated in vitro antibacterial and antifungal properties of the essential oils of Myrtus communis (McEO), as well as its phytochemical composition. The GC/MS analysis of the essential oil revealed 17 compounds. Myrtenyl acetate (20.75%), 1,8-cineol (16.55%), α-pinene (15.59%), linalool (13.30%), limonene (8.94%), linalyl acetate (3.67%), geranyl acetate (2.99%), and α-terpineol (2.88%) were the major components. The antimicrobial activity of the essential oil was also investigated on several microorganisms. The inhibition zones and minimal inhibitory concentration (MIC) values of bacterial strains were in the range of 16-28 mm and 0.078-2.5 mg/ml, respectively. The inhibitory activity of the McEO against Gram-positive bacteria was significantly higher than against Gram-negative. It also exhibited remarkable activity against several fungal strains. The investigation of the mode of action of the McEO by the time-kill curve against Listeria monocytogenes (food isolate) showed a drastic bactericidal effect after 5 min using a concentration of 312 μg/ml. These results evidence that the McEO possesses antimicrobial properties, and it is, therefore, a potential source for active ingredients for food and pharmaceutical industries. Copyright © 2014 Verlag Helvetica Chimica Acta AG, Zürich.

  18. Meat Processing Plant Microbiome and Contamination Patterns of Cold-Tolerant Bacteria Causing Food Safety and Spoilage Risks in the Manufacture of Vacuum-Packaged Cooked Sausages

    Science.gov (United States)

    Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K. Johanna

    2015-01-01

    Refrigerated food processing facilities are specific man-made niches likely to harbor cold-tolerant bacteria. To characterize this type of microbiota and study the link between processing plant and product microbiomes, we followed and compared microbiota associated with the raw materials and processing stages of a vacuum-packaged, cooked sausage product affected by a prolonged quality fluctuation with occasional spoilage manifestations during shelf life. A total of 195 samples were subjected to culturing and amplicon sequence analyses. Abundant mesophilic psychrotrophs were detected within the microbiomes throughout the different compartments of the production plant environment. However, each of the main genera of food safety and quality interest, e.g., Leuconostoc, Brochothrix, and Yersinia, had their own characteristic patterns of contamination. Bacteria from the genus Leuconostoc, commonly causing spoilage of cold-stored, modified-atmosphere-packaged foods, were detected in high abundance (up to >98%) in the sausages studied. The same operational taxonomic units (OTUs) were, however, detected in lower abundances in raw meat and emulsion (average relative abundance of 2% ± 5%), as well as on the processing plant surfaces (food safety concerns related to their resilient existence on surfaces. PMID:26231646

  19. Antimicrobial Activity of Kefir against Various Food Pathogens and Spoilage Bacteria.

    Science.gov (United States)

    Kim, Dong-Hyeon; Jeong, Dana; Kim, Hyunsook; Kang, Il-Byeong; Chon, Jung-Whan; Song, Kwang-Young; Seo, Kun-Ho

    2016-01-01

    Kefir is a unique fermented dairy product produced by a mixture of lactic acid bacteria, acetic acid bacteria, and yeast. Here, we compared the antimicrobial spectra of four types of kefirs (A, L, M, and S) fermented for 24, 36, 48, or 72 h against eight food-borne pathogens. Bacillus cereus , Staphylococcus aureus , Listeria monocytogenes , Enterococcus faecalis , Escherichia coli , Salmonella Enteritidis , Pseudomonas aeruginosa , and Cronobacter sakazakii were used as test strains, and antibacterial activity was investigated by the spot on lawn method. The spectra, potencies, and onsets of activity varied according to the type of kefir and the fermentation time. The broadest and strongest antimicrobial spectrum was obtained after at least 36-48 h of fermentation for all kefirs, although the traditional fermentation method of kefir is for 18-24 h at 25℃. For kefir A, B. cereus , E. coli , S . Enteritidis, P. aeruginosa , and C. sakazakii were inhibited, while B. cereus , S. aureus , E. coli , S . Enteritidis, P. aeruginosa , and C. sakazakii were inhibited to different extents by kefirs L, M, and S. Remarkably, S. aureus , S . Enteritidis, and C. sakazakii were only inhibited by kefirs L, M, and S, and L. monocytogenes by kefir M after fermentation for specific times, suggesting that the antimicrobial activity is attributable not only to a low pH but also to antimicrobial substances secreted during the fermentation.

  20. Antimicrobial effects of Turkish propolis, pollen, and laurel on spoilage and pathogenic food-related microorganisms.

    Science.gov (United States)

    Erkmen, Osman; Ozcan, Mehmet Musa

    2008-09-01

    The antimicrobial activities of propolis extract, pollen extract, and essential oil of laurel (Laurus nobilis L.) at concentrations from 0.02% to 2.5% (vol/vol) were investigated on bacteria (Bacillus cereus, Bacillus subtilis, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus, Yersinia enterocolitica, Enterococcus faecalis, and Listeria monocytogenes), yeasts (Saccharomyces cerevisiae and Candida rugosa), and molds (Aspergillus niger and Rhizopus oryzae). Pollen has no antimicrobial effects on the bacteria and fungi tested in the concentrations used. Propolis showed a bactericidal effect at 0.02% on B. cereus and B. subtilis, at 1.0% on S. aureus and E. faecalis, and at 0.2% on L. monocytogenes. The minimum inhibitory concentration of propolis for fungi was 2.5%. Propolis and laurel were ineffective against E. coli and S. typhimurium at the concentrations tested. The results showed that the antimicrobial activity were concentration dependent. Propolis and essential oil of laurel may be used as biopreservative agents in food processing and preservation.

  1. Evaluation and Comparison of Lactic Strains Isolated from Traditional Iranian Dairy Products (Richal Shiri with Armenian Dairy Products on Control of Food Spoilage Agents

    Directory of Open Access Journals (Sweden)

    F Karimpour

    2016-10-01

    Full Text Available Abstract Background & aim: Some bacterial metabolites isolated from fermentative products have antibacterial properties against food spoilage bacteria. The aim of this study was to evaluate the antibacterial properties of the isolated strains of traditional Armenian dairy products including cheese and traditional yogurts (Matson and Richal  shiri as a traditional dairy products from Iran. Material and method: In the present experimental study, bacterial strains were isolated, and subsequently the antibacterial activity of supernatants of strains on several types of spoilages bacteria such as Salmonella  was assessed. In addition, isolated strains from Rachel shiri showed  a good  antibacterial properties against Salmonella typhimurium. Results: The isolated strains were significantly reduced food contamination and increased the shelf -life. Furthermore, isolated strains from Richal shiri showed a good antibacterial properties against Salmonella typhimurium Conclusion: LAB strains isolated with appropriate inhibition, fermented power as a natural preservative and pragmatic as new products may be used in the dairy industry.

  2. Microbiological Spoilage of Meat and Poultry Products

    Science.gov (United States)

    Cerveny, John; Meyer, Joseph D.; Hall, Paul A.

    Humankind has consumed animal protein since the dawn of its existence. The archaeological record shows evidence of animal protein consumption as early as 12,500 BC (Mann, 2005). Raw meat and poultry are highly perishable commodities subject to various types of spoilage depending on handling and storage conditions. Because of this high potential for spoilage, the historical record reveals that early civilizations used techniques such as salting, smoking, and drying to preserve meat (Mack, 2001; Bailey, 1986). Today, more than ever, because of the globalization of the food supply, and increasing demands from exacting consumers, the control of meat and poultry spoilage is essential.

  3. Stress tolerance in fungi - to kill a spoilage yeast.

    NARCIS (Netherlands)

    Smits, G.J.; Brul, S.

    2005-01-01

    The fungal spoilage of ingredients of food manufacture is an economic problem, often causes product loss and may constitute a health hazard. To effectively combat fungal food spoilage, a mechanistic understanding of tolerance for, and adaptation to, the preservation method used is crucial. Both are

  4. The effect of metal ions commonly present in food on gene expression of sporulating Bacillus subtilis cells in relation to spore wet heat resistance.

    NARCIS (Netherlands)

    Oomes, S.J.C.M.; Brul, S.

    2004-01-01

    Bacillus subtilis is a food spoilage spore-forming bacterium. The spores can be very heat-resistant and may cause problems in the production of foods. Varying the metal concentration in the sporulation media is known to influence the heat resistance of the spores. The effect of changing the metal

  5. Microbiological Spoilage of Spices, Nuts, Cocoa, and Coffee

    Science.gov (United States)

    Pinkas, Joan M.; Battista, Karen; Morille-Hinds, Theodora

    Spices, nuts, cocoa, and coffee are raw materials that may be used alone or as ingredients in the manufacture of processed food products. The control of microbiological spoilage of these raw materials at the ingredient stage will enable the food processor to better assure the production of high-quality foods with an acceptable shelf life. While this chapter is limited to four materials, many of the spoilage control procedures recommended can also be applied to other raw materials of a similar nature.

  6. Detection of food spoilage and pathogenic bacteria based on ligation detection reaction coupled to flow-through hybridization on membranes.

    Science.gov (United States)

    Böhme, K; Cremonesi, P; Severgnini, M; Villa, Tomás G; Fernández-No, I C; Barros-Velázquez, J; Castiglioni, B; Calo-Mata, P

    2014-01-01

    Traditional culturing methods are still commonly applied for bacterial identification in the food control sector, despite being time and labor intensive. Microarray technologies represent an interesting alternative. However, they require higher costs and technical expertise, making them still inappropriate for microbial routine analysis. The present study describes the development of an efficient method for bacterial identification based on flow-through reverse dot-blot (FT-RDB) hybridization on membranes, coupled to the high specific ligation detection reaction (LDR). First, the methodology was optimized by testing different types of ligase enzymes, labeling, and membranes. Furthermore, specific oligonucleotide probes were designed based on the 16S rRNA gene, using the bioinformatic tool Oligonucleotide Retrieving for Molecular Applications (ORMA). Four probes were selected and synthesized, being specific for Aeromonas spp., Pseudomonas spp., Shewanella spp., and Morganella morganii, respectively. For the validation of the probes, 16 reference strains from type culture collections were tested by LDR and FT-RDB hybridization using universal arrays spotted onto membranes. In conclusion, the described methodology could be applied for the rapid, accurate, and cost-effective identification of bacterial species, exhibiting special relevance in food safety and quality.

  7. Detection of Food Spoilage and Pathogenic Bacteria Based on Ligation Detection Reaction Coupled to Flow-Through Hybridization on Membranes

    Directory of Open Access Journals (Sweden)

    K. Böhme

    2014-01-01

    Full Text Available Traditional culturing methods are still commonly applied for bacterial identification in the food control sector, despite being time and labor intensive. Microarray technologies represent an interesting alternative. However, they require higher costs and technical expertise, making them still inappropriate for microbial routine analysis. The present study describes the development of an efficient method for bacterial identification based on flow-through reverse dot-blot (FT-RDB hybridization on membranes, coupled to the high specific ligation detection reaction (LDR. First, the methodology was optimized by testing different types of ligase enzymes, labeling, and membranes. Furthermore, specific oligonucleotide probes were designed based on the 16S rRNA gene, using the bioinformatic tool Oligonucleotide Retrieving for Molecular Applications (ORMA. Four probes were selected and synthesized, being specific for Aeromonas spp., Pseudomonas spp., Shewanella spp., and Morganella morganii, respectively. For the validation of the probes, 16 reference strains from type culture collections were tested by LDR and FT-RDB hybridization using universal arrays spotted onto membranes. In conclusion, the described methodology could be applied for the rapid, accurate, and cost-effective identification of bacterial species, exhibiting special relevance in food safety and quality.

  8. Detection of Food Spoilage and Pathogenic Bacteria Based on Ligation Detection Reaction Coupled to Flow-Through Hybridization on Membranes

    Science.gov (United States)

    Böhme, K.; Cremonesi, P.; Severgnini, M.; Villa, Tomás G.; Fernández-No, I. C.; Barros-Velázquez, J.; Castiglioni, B.; Calo-Mata, P.

    2014-01-01

    Traditional culturing methods are still commonly applied for bacterial identification in the food control sector, despite being time and labor intensive. Microarray technologies represent an interesting alternative. However, they require higher costs and technical expertise, making them still inappropriate for microbial routine analysis. The present study describes the development of an efficient method for bacterial identification based on flow-through reverse dot-blot (FT-RDB) hybridization on membranes, coupled to the high specific ligation detection reaction (LDR). First, the methodology was optimized by testing different types of ligase enzymes, labeling, and membranes. Furthermore, specific oligonucleotide probes were designed based on the 16S rRNA gene, using the bioinformatic tool Oligonucleotide Retrieving for Molecular Applications (ORMA). Four probes were selected and synthesized, being specific for Aeromonas spp., Pseudomonas spp., Shewanella spp., and Morganella morganii, respectively. For the validation of the probes, 16 reference strains from type culture collections were tested by LDR and FT-RDB hybridization using universal arrays spotted onto membranes. In conclusion, the described methodology could be applied for the rapid, accurate, and cost-effective identification of bacterial species, exhibiting special relevance in food safety and quality. PMID:24818128

  9. Bacteriophages against Serratia as Fish Spoilage Control Technology

    OpenAIRE

    Hern?ndez, Igor

    2017-01-01

    Bacteria of the genus Serratia, mainly S. proteamaculans and S. fonticola, are important spoilage agents in Atlantic horse mackerel (Trachurus trachurus). In order to evaluate whether bacteriophages against Serratia could delay the spoilage process, 11 viral strains active against this genus were isolated from food and best candidate was applied to fresh mackerel filets. All the phages belong to the Siphoviridae and Podoviridae families and were active at multiplicity of infection (MOI) level...

  10. Spoilage potential of psychrotrophic lactic acid bacteria (LAB) species: Leuconostoc gelidum subsp. gasicomitatum and Lactococcus piscium, on sweet bell pepper (SBP) simulation medium under different gas compositions.

    Science.gov (United States)

    Pothakos, Vasileios; Nyambi, Clarice; Zhang, Bao-Yu; Papastergiadis, Antonios; De Meulenaer, Bruno; Devlieghere, Frank

    2014-05-16

    Sweet bell peppers are a significant constituent of retail, chilled-stored and packaged food products like fresh salads, marinades and ready-to-eat (RTE) meals. Previously, through general screening of the Belgian market and by means of source tracking analysis in a plant manufacturing minimally processed, vegetable salads the susceptibility of fresh-cut sweet bell peppers to lactic acid bacterium (LAB) contamination was substantiated. The determination of the metabolic profiles of Leuconostoc gelidum subsp. gasicomitatum and Lactococcus piscium, two major psychrotrophic, spoilage-related LAB species, on sweet bell pepper (SBP) simulation medium under different packaging conditions - 1.) vacuum: 100% N2, 2.) air: 21% O2, 79% N2, 3.) MAP1: 30% CO2, 70% N2 and 4.) MAP2: 50% O2, 50% CO2 - facilitated a better understanding of the spoilage potential of these microbes as well as the presumptive contribution of O2 in the spectrum of produced volatile organic compounds (VOCs) associated with poor organoleptic properties of food products. Generally, none of the applied gas compositions inhibited the growth of the 4 L. gelidum subsp. gasicomitatum isolates, however the presence of O2 resulted in buttery off-odors by inducing primarily the accumulation of diacetyl and pungent "vinegar" smell due to acetic acid. The 3 tested isolates of L. piscium varied greatly among their growth dynamics and inhibition at MAP2. They exhibited either weak spoilage profile or very offensive metabolism confirming significant intraspecies diversity. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. The ZbYME2 gene from the food spoilage yeast Zygosaccharomyces bailii confers not only YME2 functions in Saccharomyces cerevisiae, but also the capacity for catabolism of sorbate and benzoate, two major weak organic acid preservatives.

    Science.gov (United States)

    Mollapour, M; Piper, P W

    2001-11-01

    A factor influencing resistances of food spoilage microbes to sorbate and benzoate is whether these organisms are able to catalyse the degradation of these preservative compounds. Several fungi metabolize benzoic acid by the beta-ketoadipate pathway, involving the hydroxylation of benzoate to 4-hydroxybenzoate. Saccharomyces cerevisiae is unable to use benzoate as a sole carbon source, apparently through the lack of benzoate-4-hydroxylase activity. However a single gene from the food spoilage yeast Zygosaccharomyces bailii, heterologously expressed in S. cerevisiae cells, can enable growth of the latter on benzoate, sorbate and phenylalanine. Although this ZbYME2 gene is essential for benzoate utilization by Z. bailii, its ZbYme2p product has little homology to other fungal benzoate-4-hydroxylases studied to date, all of which appear to be microsomal cytochrome P450s. Instead, ZbYme2p has strong similarity to the matrix domain of the S. cerevisiae mitochondrial protein Yme2p/Rna12p/Prp12p and, when expressed as a functional fusion to green fluorescent protein in S. cerevisiae growing on benzoate, is largely localized to mitochondria. The phenotypes associated with loss of the native Yme2p from S. cerevisiae, mostly apparent in yme1,yme2 cells, may relate to increased detrimental effects of endogenous oxidative stress. Heterologous expression of ZbYME2 complements these phenotypes, yet it also confers a potential for weak acid preservative catabolism that the native S. cerevisiae Yme2p is unable to provide. Benzoate utilization by S. cerevisiae expressing ZbYME2 requires a functional mitochondrial respiratory chain, but not the native Yme1p and Yme2p of the mitochondrion.

  12. Characterization of cucumber fermentation spoilage bacteria by enrichment culture and 16S rDNA cloning.

    Science.gov (United States)

    Breidt, Fred; Medina, Eduardo; Wafa, Doria; Pérez-Díaz, Ilenys; Franco, Wendy; Huang, Hsin-Yu; Johanningsmeier, Suzanne D; Kim, Jae Ho

    2013-03-01

    Commercial cucumber fermentations are typically carried out in 40000 L fermentation tanks. A secondary fermentation can occur after sugars are consumed that results in the formation of acetic, propionic, and butyric acids, concomitantly with the loss of lactic acid and an increase in pH. Spoilage fermentations can result in significant economic loss for industrial producers. The microbiota that result in spoilage remain incompletely defined. Previous studies have implicated yeasts, lactic acid bacteria, enterobacteriaceae, and Clostridia as having a role in spoilage fermentations. We report that Propionibacterium and Pectinatus isolates from cucumber fermentation spoilage converted lactic acid to propionic acid, increasing pH. The analysis of 16S rDNA cloning libraries confirmed and expanded the knowledge gained from previous studies using classical microbiological methods. Our data show that Gram-negative anaerobic bacteria supersede Gram-positive Fermincutes species after the pH rises from around 3.2 to pH 5, and propionic and butyric acids are produced. Characterization of the spoilage microbiota is an important first step in efforts to prevent cucumber fermentation spoilage. An understanding of the microorganisms that cause commercial cucumber fermentation spoilage may aid in developing methods to prevent the spoilage from occurring. © 2013 Institute of Food Technologists®

  13. Fish spoilage bacteria - problems and solutions

    DEFF Research Database (Denmark)

    Gram, Lone; Dalgaard, Paw

    2002-01-01

    Microorganisms are the major cause of spoilage of most seafood products. However, only a few members of the microbial community, the specific spoilage organisms (SSOs), give rise to the offensive off-flavours associated with seafood spoilage. Combining microbial ecology, molecular techniques, ana...

  14. Growth characteristics and biofilm formation of various spoilage bacteria isolated from fresh produce.

    Science.gov (United States)

    Bae, Young-Min; Zheng, Ling; Hyun, Jeong-Eun; Jung, Kyu-Seok; Heu, Sunggi; Lee, Sun-Young

    2014-10-01

    This study investigated the characteristics of spoilage bacteria isolated from fresh produce including growth at various temperatures, biofilm formation, cell hydrophobicity, and colony spreading. The number of spoilage bacteria present when stored at 35 °C was significantly greater than when stored at lower temperatures, and maximum population size was achieved after 10 h. However, Bacillus pumilus, Dickeya zeae, Pectobacterium carotovorum subsp. Carotovorum Pcc21, and Bacillus pumilus (RDA-R) did not grow at the storage temperature of 5 °C. The biofilm formation by Clavibacter michiganensis, Acinetobacter calcoaceticus, and A. calcoaceticus (RDA-R) are higher than other spoilage bacteria. Biofilm formation showed low correlation between hydrophobicity, and no significant correlation with colony spreading. These results might be used for developing safe storage guidelines for fresh produce at various storage temperatures, and could be basic information on the growth characteristics and biofilm formation properties of spoilage bacteria from fresh produce. Growth of spoilage bacteria was different depending on the bacteria strains and storage temperature. Between biofilm formation and cell hydrophobicity was low correlation on spoilage bacteria. Therefore, growth characteristics and biofilm formation of spoilage bacteria might be used for developing safe storage guidelines for fresh produce at various storage temperatures. © 2014 Institute of Food Technologists®

  15. The spoilage yeast Zygosaccharomyces bailii: Foe or friend?

    Science.gov (United States)

    Kuanyshev, Nurzhan; Adamo, Giusy M; Porro, Danilo; Branduardi, Paola

    2017-09-01

    Zygosaccharomyces bailii is a non-Saccharomyces budding yeast known as one of the most aggressive food spoilage microorganisms, often isolated as a contaminant during wine fermentation, as well as from many acidic, high-sugar and canned foods. The spoilage ability relies on the yeast's unique feature of tolerating the most common preservatives such as sulphite, dimethyl dicarbonate, acetic acid and sorbic acid. Therefore, many studies have focused on the description of this peculiar tolerance with the aim of developing preventative measures against Z. bailii food spoilage. These studies demonstrated the involvement of diverse molecular and physiological mechanisms in the yeast resistance, comprising detoxification of preservatives, adaptation of the cytoplasmic pH and modulation of the cell wall/membrane composition. At the same time, the described traits unveiled Z. bailii as a novel potential workhorse for industrial bioprocesses. Here we present the yeast Z. bailii starting from important aspects of its robustness and concluding with the exploitation of its potential in biotechnology. Overall, the article describes Z. bailii from different perspectives, converging in presenting it as one of the most interesting species of the Saccharomycotina subphylum. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Microbiological spoilage of fish and fish products

    DEFF Research Database (Denmark)

    Gram, Lone; Huss, Hans Henrik

    1996-01-01

    biochemical indicators of spoilage. Shewanzella putrefaciens and Pseudomonas spp. are the specific spoilage bacteria of iced fresh fish regardless of the origin of the fish. Modified atmosphere stored marine fish from temperate waters are spoiled by the CO2 resistant Photobacterium phosphoreum whereas Gram......Spoilage of fresh and lightly preserved fish products is caused by microbial action. This paper reviews the current knowledge in terms of the microbiology of fish and fish products with particular emphasis on identification of specific spoilage bacteria and the qualitative and quantitative...

  17. Lactobacilli and tartrazine as causative agents of red-color spoilage in cucumber pickle products.

    Science.gov (United States)

    Pérez-Díaz, I M; Kelling, R E; Hale, S; Breidt, F; McFeeters, R F

    2007-09-01

    The cucumber pickling industry has sporadically experienced spoilage outbreaks in pickled cucumber products characterized by development of red color on the surface of the fruits. Lactobacillus casei and Lactobacillus paracasei were isolated from 2 outbreaks of this spoilage that occurred about 15 y apart during the last 3 decades. Both organisms were shown to produce this spoilage when inoculated into pickled cucumbers while concomitantly degrading the azo dye tartrazine (FD&C yellow nr 5). This food dye is used as a yellow coloring in the brine cover solutions of commercial pickled cucumber products. The red color does not occur in the absence of tartrazine, nor when turmeric is used as a yellow coloring in the pickles. Addition of sodium benzoate to the brine cover solutions of a pickled cucumber product, more specifically hamburger dill pickles, prevented growth of these lactic acid bacteria and the development of the red spoilage.

  18. Chemical composition and antioxidative activity of Echinophora platyloba DC. essential oil, and its interaction with natural antimicrobials against food-borne pathogens and spoilage organisms.

    Science.gov (United States)

    Saei-Dehkordi, S Siavash; Fallah, Aziz A; Saei-Dehkordi, S Saeid; Kousha, Sanaz

    2012-11-01

    This study was undertaken to determine the chemical composition and antioxidative capacity of Echinophora platyloba DC. essential oil, and its antimicrobial potency against Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157:H7, Pseudomonas aeruginosa, Candida albicans, Candida tropicalis, Rhodotorula rubra, and Rhodotorula mucilaginosa. The essential oil was analyzed by GC and GC-MS; and evaluated for its antioxidative and antimicrobial (singly or in combination with chitosan, nisin, monolaurin, or amphotericin B) activity. Thirty-three components were characterized representing 95.69% of the total oil composition in which thymol, trans-ocimene, carvacrol, and (E)-sesqui-lavandulol were the major constituents. The oil exhibited high scavenging (IC(50): 49.7 ± 2.3 μg/mL) and relative antioxidative activity (RAA%: 85.21 ± 0.4) in 1,1-diphenyl-2-picrylhydrazyl radicals and β-carotene/linoleic acid bleaching assays, respectively. The oil showed antimicrobial activity against L. monocytogenes, B. cereus, B. subtilis, S. aureus, S. typhimurium, E. coli O157:H7, P. aeruginosa, C. albicans, C. tropicalis, R. Rubra, and R. mucilaginosa. Moreover, R. mucilaginosa and P. aeruginosa were the most susceptible and most resistant organisms, respectively. Regarding the checkerboard data, 47 fractional inhibitory concentration index (FICIs) (≤ 0.5) indicated synergistic, whereas 7 FICIs (>0.5 to 1) indicated additive effect. Consequently, E. platyloba DC. essential oil could be used as a recommended natural antioxidant and antimicrobial substance for food preservation. © 2012 Institute of Food Technologists®

  19. Effect of antioxidant and optimal antimicrobial mixtures of carvacrol, grape seed extract and chitosan on different spoilage microorganisms and their application as coatings on different food matrices

    Directory of Open Access Journals (Sweden)

    Javiera F. Rubilar

    2013-04-01

    Full Text Available There is growing interest in the use of natural agents with antimicrobial (AM and antioxidant (AOX properties. Optimization of the AM capacity for mixtures containing carvacrol, grape seed extract (GSE and chitosan, against gram-negative (Pseudomonas aeruginosa, gram-positive bacteria (Staphylococcus aureus, Listeria innocua and Enterococcus faecalis and yeast (Saccharomyces cerevisiae at 106 cfu mL-1 was studied. To observe the synergistic or antagonistic effect and find optimal combinations between the three agents, a simplex centroid mixture design was run for each microorganism, combining carvacrol (0-300 ppm, X1, GSE (0-2000 ppm, X2 and chitosan (0-2% w/v, X3. Results of the response surface analysis showed several synergistic effects for all microorganisms. Combinations of 60 ppm-400 ppm-1.2% w/v (carvacrol-GSE-chitosan; optimal AM combination 1, OAMC-1; 9.6 ppm-684 ppm-1.25% w/v (OAMC-2; 90 ppm-160 ppm-1.24% w/v (OAMC-3 were found to be the optimal mixtures for all microorganisms. Radical scavenging activity (RSA of the same agents was then compared with a standard AOX (butylated hydroxytoluene; BHT at different concentrations (25, 50 and 100 ppm; as well as the optimal AM concentrations by the 1,1-diphenyl-2-picrylhydrazyl (DPPH method. RSA increased in the following order: chitosan< carvacrol< BHT< GSE and for the OAMC: OAMC-2< OAMC-1< OAMC-3. The best RSA (OAMC-3 was applied as a coating in two different food matrices (strawberries and salmon. For strawberries, P. aeruginosa was more sensitive to the action of OAMC-3 than S. cerevisiae. For salmon, S. aureus was more resistant to the action of OAMC-3 than E. faecalis and L. innocua.

  20. Characterization and control of Mucor circinelloides spoilage in yogurt.

    Science.gov (United States)

    Snyder, Abigail B; Churey, John J; Worobo, Randy W

    2016-07-02

    Consumer confidence in the food industry is severely affected by large-scale spoilage incidents. However, relatively little research exists on spoilage potential of members of the fungal subphylum Mucormycotina (e.g. Mucor), which includes dimorphic spoilage organisms that can switch between a yeast-like and hyphal phase depending on environmental conditions. The presence of Mucor circinelloides in yogurt may not cause spoilage, but growth and subsequent changes in quality (e.g. container bloating) can cause spoilage if not controlled. The purpose of this study was to evaluate the effects on M. circinelloides of pasteurization regimen, natamycin concentrations, and storage temperature in yogurt production, as measured by fungal proliferation and carbon dioxide production. A strain of M. circinelloides isolated from commercially spoiled yogurt showed greater yogurt-spoilage potential than clinical isolates and other industrial strains. D-values and z-values were determined for the spoilage isolate in milk as an evaluation of the fungus' ability to survive pasteurization. Natamycin was added to yogurt at 0, 5, 10, 15, and 20ppm (μg/ml) to determine its ability to inhibit M. circinelloides over the course of month-long challenge studies at 4°C, 15°C, and 25°C. Survivors were recovered on acidified PDA and carbon dioxide levels were recorded. The D-values at 54°C, 56°C, and 58°C for hyphae/sporangiospores were (in min) 38.31±0.02, 10.17±0.28, and 1.94±0.53, respectively, which yielded a z-value of 3.09°C. The D-values at 51°C, 53°C, and 55°C for yeast-like cells were (in min) 14.25±0.12, 6.87±1.19, and 2.44±0.35, respectively, which yielded a z-value of 0.34°C. These results indicated that M. circinelloides would not survive fluid milk pasteurization if contamination occurred prior to thermal treatment. CO2 production was only observed when M. circinelloides was incubated under low-oxygen conditions, and occurred only at temperatures above 4

  1. Beer spoilage bacteria and hop resistance

    NARCIS (Netherlands)

    Sakamoto, K; Konings, WN

    2003-01-01

    For brewing industry, beer spoilage bacteria have been problematic for centuries. They include some lactic acid bacteria such as Lactobacillus brevis, Lactobacillus lindneri and Pediococcus damnosus, and some Gram-negative bacteria such as Pectinatus cerevisiiphilus, Pectinatus frisingensis and

  2. Spoilage microorganisms in milk and dairy products

    Directory of Open Access Journals (Sweden)

    Andrea Skelin

    2007-12-01

    Full Text Available Spoilage microorganisms cause changes of primary characteristics and properties of milk and dairy products. The product defects depends on the specific species and number of microorganisms involved in pre- and post- technological processing. Most often, these changes are related to single undesirable sensory characteristic, smell, flavour or conistency. However, in the case of heavier microbial contamination all these undesirable characteristics can occur simultaneously. Besides, even small changes caused by presence of spoilage microorganisms lead to decreased quality of milk and various dairy products. Despite of the importance for the overall quality, the control of spoilage microorganisms for dairy industry is not obligated and therefore, only a few producers control them. Therefore, the present study describes the undesirable effect of spoilage microorganisms on quality of raw, pasteurized and sterilized milk, fermented milk, butter, sour cream and cheeses with the intention to emphasize the importance and significance of their control in the dairy industry.

  3. Reducing Salt in Raw Pork Sausages Increases Spoilage and Correlates with Reduced Bacterial Diversity

    Science.gov (United States)

    Fougy, Lysiane; Desmonts, Marie-Hélène; Coeuret, Gwendoline; Fassel, Christine; Hamon, Erwann; Hézard, Bernard; Champomier-Vergès, Marie-Christine

    2016-01-01

    dietary salt intake. However, salt has been used for a very long time as a hurdle technology, and salt reduction in meat products raises the question of spoilage and waste of food. The study was conceived to assess the role of sodium chloride reduction in meat products, both at the level of spoilage development and at the level of bacterial diversity, using 16S rRNA amplicon sequencing and raw pork sausage as a meat model. PMID:27107120

  4. Reducing Salt in Raw Pork Sausages Increases Spoilage and Correlates with Reduced Bacterial Diversity.

    Science.gov (United States)

    Fougy, Lysiane; Desmonts, Marie-Hélène; Coeuret, Gwendoline; Fassel, Christine; Hamon, Erwann; Hézard, Bernard; Champomier-Vergès, Marie-Christine; Chaillou, Stéphane

    2016-07-01

    . However, salt has been used for a very long time as a hurdle technology, and salt reduction in meat products raises the question of spoilage and waste of food. The study was conceived to assess the role of sodium chloride reduction in meat products, both at the level of spoilage development and at the level of bacterial diversity, using 16S rRNA amplicon sequencing and raw pork sausage as a meat model. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  5. Influence of sodium chloride, pH, and lactic acid bacteria on anaerobic lactic acid utilization during fermented cucumber spoilage.

    Science.gov (United States)

    Johanningsmeier, Suzanne D; Franco, Wendy; Perez-Diaz, Ilenys; McFeeters, Roger F

    2012-07-01

    by spoilage microorganisms in reduced salt, even with pH as low as 3.2. Efforts to reduce salt in commercial brining operations will need to include control measures for this increased susceptibility to spoilage. Lactobacillus buchneri was identified as a potential causative agent and could be used as a target in development of such control measures. Journal of Food Science © 2012 Institute of Food Technologists® No claim to original US government works.

  6. Classification of photobacteria associated with spoilage of fish products by numerical taxanomy and pyrolysis mass spectrometry

    DEFF Research Database (Denmark)

    Dalgaard, Paw; Manfio, G.P.; Goodfellow, M.

    1997-01-01

    sub-groups. One sub-group of psychrotolerant P. phosphoreum strains, which was selected in modified atmosphere packed fish stored at low temperature, was also highlighted using each of the methods. The importance of classifying food spoilage bacteria has been shown and a simple key generated...

  7. Growth inhibitory effect of grape phenolics against wine spoilage yeasts and acetic acid bacteria

    Czech Academy of Sciences Publication Activity Database

    Pastorková, E.; Žáková, T.; Landa, Přemysl; Nováková, J.; Vadlejch, J.; Kokoška, L.

    2013-01-01

    Roč. 161, č. 3 (2013), s. 209-213 ISSN 0168-1605 R&D Projects: GA MŠk(CZ) LD11005 Institutional research plan: CEZ:AV0Z50380511 Keywords : Phenolic compound * Antimicrobial activity * Wine spoilage microorganism Subject RIV: GM - Food Processing Impact factor: 3.155, year: 2013

  8. Mapping microbial ecosystems and spoilage-gene flow in breweries highlights patterns of contamination and resistance.

    Science.gov (United States)

    Bokulich, Nicholas A; Bergsveinson, Jordyn; Ziola, Barry; Mills, David A

    2015-03-10

    Distinct microbial ecosystems have evolved to meet the challenges of indoor environments, shaping the microbial communities that interact most with modern human activities. Microbial transmission in food-processing facilities has an enormous impact on the qualities and healthfulness of foods, beneficially or detrimentally interacting with food products. To explore modes of microbial transmission and spoilage-gene frequency in a commercial food-production scenario, we profiled hop-resistance gene frequencies and bacterial and fungal communities in a brewery. We employed a Bayesian approach for predicting routes of contamination, revealing critical control points for microbial management. Physically mapping microbial populations over time illustrates patterns of dispersal and identifies potential contaminant reservoirs within this environment. Habitual exposure to beer is associated with increased abundance of spoilage genes, predicting greater contamination risk. Elucidating the genetic landscapes of indoor environments poses important practical implications for food-production systems and these concepts are translatable to other built environments.

  9. Bacteriophages againstSerratiaas Fish Spoilage Control Technology.

    Science.gov (United States)

    Hernández, Igor

    2017-01-01

    Bacteria of the genus Serratia , mainly S. proteamaculans and S. fonticola , are important spoilage agents in Atlantic horse mackerel ( Trachurus trachurus ). In order to evaluate whether bacteriophages against Serratia could delay the spoilage process, 11 viral strains active against this genus were isolated from food and best candidate was applied to fresh mackerel filets. All the phages belong to the Siphoviridae and Podoviridae families and were active at multiplicity of infection (MOI) levels below 1:1 in Long & Hammer broth. The ability of phage AZT6 to control Serratia populations in real food was tested in Atlantic horse mackerel extract and applied to fresh mackerel filets. Treatment with high phage concentration (MOI 350:1, initial Serratia population 3.9 ± 0.3 Log cfu/g) can reduce the Serratia populations up to 90% during fish storage (a maximum of 6 days) at low temperatures (6°C). Bacterial inhibition was dependent on the bacteriophage dosage, and MOI of 10:1 or lower did not significantly affect the Serratia populations.

  10. Isolation and Identification of Spoilage Fungi Associated With Rice ...

    African Journals Online (AJOL)

    The spoilage fungi isolated were Aspergillus species, Rhizopus, Penicilluim, Fusarium, Eurotium, Mucor, Geotrichum, Alternaria, Cladosporium and Actinomyces species. The predominant spoilage fungi in the grains were Aspergillus species. The populations of some spoilage fungi isolated from the grains were not high ...

  11. Modeling growth of specific spoilage organisms in tilapia ...

    African Journals Online (AJOL)

    enoh

    2012-03-29

    Mar 29, 2012 ... Tilapia is an important aquatic fish, but severe spoilage of tilapia is most likely related to the global aquaculture. The spoilage is mostly caused by specific spoilage organisms (SSO). Therefore, it is very important to use microbial models to predict the growth of SSO in tilapia. This study firstly verified.

  12. Modeling growth of specific spoilage organisms in tilapia ...

    African Journals Online (AJOL)

    Tilapia is an important aquatic fish, but severe spoilage of tilapia is most likely related to the global aquaculture. The spoilage is mostly caused by specific spoilage organisms (SSO). Therefore, it is very important to use microbial models to predict the growth of SSO in tilapia. This study firstly verified Pseudomonas and Vibrio ...

  13. A Rapid Detection of Meat Spoilage using an Electronic Nose and Fuzzy-Wavelet systems

    OpenAIRE

    Kodogiannis, V.

    2018-01-01

    Freshness and safety of muscle foods are generally considered as the most important parameters for the food industry. To address the rapid detection of meat spoilage microorganisms during aerobic or modified atmosphere storage, an electronic nose with the aid of fuzzy wavelet network has been considered in this research. The proposed model incorporates a clustering pre-processing stage for the definition of fuzzy rules. The dual purpose of the proposed modelling approach is not only to classi...

  14. Bioactive proteins against pathogenic and spoilage bacteria

    Directory of Open Access Journals (Sweden)

    Mahmoud Z. Sitohy

    2014-10-01

    Full Text Available Background: It is likely that both human nutrition and the nutrition of livestock are benefited by the presence of bioactive proteins within their respective diet regimes. Bioactive proteins have been defined as specific protein fragments that positively impact bodily functions or conditions and may, ultimately, influence overall human health. The ingestion of bioactive proteins may have an effect on the major body systems—namely, the cardiovascular, digestive, immune and nervous systems. According to their functional properties, bioactive proteins may be classified as antimicrobial, antithrombotic, antihypertensive, opioid, immune-modulatory, mineral binding and anti-oxidative. There are many examples of biologically active food proteins and active peptides that can be obtained from various food protein sources. They have a physiological significance beyond the pure nutritional requirements; in other wordsthey have the acquisition of nitrogen for normal growth and maintenance. Objective: This study aims to specify and characterize the extent and mode of action of bioactive proteins in their native form, (glycinin, glycinin basic sub-unit and β-conglycinin against specific main pathogens (Listeria monocytogenes, Escherichia coli O157:H7 and Salmonella enterica serovar Enteritidis. We will be using standard media while identifying the main constituents responsible for this action. Methods: Glycinin, basic sub-unit and β-conglycinin were isolated from soybean protein and tested for their antimicrobial action against pathogenic and spoilage bacteria, They were thencompared to the properties of penicillin. Methylated soybean protein and also methylated chickpea protein (MSP and MCP, with isoelectric points around pI 8, were prepared by esterifying. 83 % of their free carboxyl groups and their interactions with Gram positive and Gram negative bacteria were examined. Results: The three divisions of cationic proteins exhibited antibacterial

  15. Characterisation of the spoilage bacterial microbiota in oyster gills during storage at different temperatures.

    Science.gov (United States)

    Chen, Huibin; Liu, Zhiyu; Wang, Meiying; Chen, Shaojun; Chen, Tuanwei

    2013-12-01

    The spoilage bacterial community in oyster gill was investigated during storage at 4, 10 and 20 °C. Aerobic plate counts and pH values were determined. Total bacterial DNA was extracted from oyster gill and bulk cells of plate count media. The major bacterial species during fresh or different temperatures storage were determined by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The initial aerobic plate count in oyster gill reached 6.70 log CFU g(-1). PCR-DGGE fingerprinting analysis of the 16S rRNA gene V3 region revealed that most of the strains in fresh oyster gill belonged to the genera Lactococcus and Enterobacter. The major spoilage bacteria at a storage temperature of 20 °C were Leuconostoc pseudomesenteroides, an uncultured bacterium, Cytophaga fermentans, Lactococcus lactis, Pseudoalteromonas sp., Enterococcus mundtii, Clostridium difficile and an uncultured Fusobacteria; those at 10 °C were Lactococcus spp., Lactobacillus curvatus, Weissella confusa and C. difficile; those at 4 °C were Lactococcus, Weissella, Enterobacter and Aeromonas. The other minor species were L. curvatus, Pseudomonas sp. and E. mundtii. Lactococcus spp. was the most common main spoilage bacteria in oyster gill during chilled storage. PCR-DGGE revealed the complexity of the bacterial microbiota and the major bacteria species in oyster gill for fresh and storage. © 2013 Society of Chemical Industry.

  16. Xanthine oxidase biosensor for monitoring meat spoilage

    Science.gov (United States)

    Vanegas, D. C.; Gomes, C.; McLamore, E. S.

    2014-05-01

    In this study, we have designed an electrochemical biosensor for real-time detection of specific biomarkers of bacterial metabolism related to meat spoilage (hypoxanthine and xanthine). The selective biosensor was developed by assembling a `sandwich' of nanomaterials and enzymes on a platinum-iridium electrode (1.6 mm tip diameter). The materials deposited on the sensor tip include amorphous platinum nanoclusters (i.e. Pt black), reduced graphene oxide, nanoceria, and xanthine oxidase. Xanthine oxidase was encapsulated in laponite hydrogel and used for the biorecognition of hypoxanthine and xanthine (two molecules involved in the rotting of meat by spoilage microorganisms). The developed biosensor demonstrated good electrochemical performance toward xanthine with sensitivity of 2.14 +/- 1.48 μA/mM, response time of 5.2 +/- 1.5 sec, lower detection limit of 150 +/- 39 nM, and retained at least 88% of its activity after 7 days of continuous use.

  17. Detection and quantification of bacterial spoilage in milk and pork meat using MALDI-TOF-MS and multivariate analysis.

    Science.gov (United States)

    Nicolaou, Nicoletta; Xu, Yun; Goodacre, Royston

    2012-07-17

    Microbiological safety is one of the cornerstones of quality control in the food industry. Identification and quantification of spoilage bacteria in pasteurized milk and meat in the food industry currently relies on accurate and sensitive yet time-consuming techniques which give retrospective values for microbial contamination. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), a proven technique in the field of protein and peptide identification and quantification, may be a valuable alternative approach for the rapid assessment of microbial spoilage. In this work we therefore developed MALDI-TOF-MS as a novel analytical approach for the assessment of food that when combined with chemometrics allows for the detection and quantification of milk and pork meat spoilage bacteria. To develop this approach, natural spoilage of pasteurized milk and raw pork meat samples incubated at 15 °C and at room temperature, respectively, was conducted. Samples were collected for MALDI-TOF-MS analysis (which took 4 min per sample) at regular time intervals throughout the spoilage process, with concurrent calculation and documentation of reference total viable counts using traditional microbiological methods (these took 2 days). Multivariate statistical techniques such as principal component discriminant function analysis, canonical correlation analysis, partial least-squares (PLS) regression, and kernel PLS (KPLS) were used to analyze the data. The results from MALDI-TOF-MS combined with PLS or KPLS gave excellent bacterial quantification results for both milk and meat spoilage, and typical root mean squared errors for prediction in test spectra were between 0.53 and 0.79 log unit. Overall these novel findings strongly indicate that MALDI-TOF-MS when combined with chemometric approaches would be a useful adjunct for routine use in the milk and meat industry as a fast and accurate viable bacterial detection and quantification method.

  18. Microbiological Spoilage of High-Sugar Products

    Science.gov (United States)

    Thompson, Sterling

    The high-sugar products discussed in this chapter are referred to as chocolate, sugar confectionery (non-chocolate), liquid sugars, sugar syrups, and honey. Products grouped in the sugar confectionery category include hard candy, soft/gummy candy, caramel, toffee, licorice, marzipan, creams, jellies, and nougats. A common intrinsic parameter associated with high-sugar products is their low water activity (a w), which is known to inhibit the growth of most spoilage and pathogenic bacteria. However, spoilage can occur as a result of the growth of osmophilic yeasts and xerophilic molds (Von Richter, 1912; Anand & Brown, 1968; Brown, 1976). The a w range for high-sugar products is between 0.20 and 0.80 (Banwart, 1979; Richardson, 1987; Lenovich & Konkel, 1992; ICMSF, 1998; Jay, Loessner, & Golden, 2005). Spoilage of products, such as chocolate-covered cherries, results from the presence of yeasts in the liquid sugar brine or the cherry. Generally, the spoiled product will develop leakers. The chocolate covering the cherry would not likely be a source of yeast contamination.

  19. Investigation of spoilage in saveloy samples inoculated with four potential spoilage bacteria

    DEFF Research Database (Denmark)

    Holm, Esben Skibsted; Schäfer, A.; Koch, A.G.

    2013-01-01

    Sliced saveloy samples were inoculated with monocultures of four potential spoilage bacteria and studied during a four week storage period. The objective was to investigate the resulting changes in the composition of Volatile Organic Compounds (VOCs) and the sensory quality of the product. Based...... on the sensory scores and the VOC composition Brochothrix thermosphacta, Chryseomonas luteola and Carnobacterium maltaromaticum were found to have a high spoilage potential in saveloy samples subjected to consumer simulated storage during the fourth week. Inoculation with Leuconostoc carnosum only resulted...... in a low level of spoilage. The sensory changes in the saveloy samples were modeled based on the VOC composition using Partial Least Squares Regression. The changes in the six sensory descriptors were closely related to the amount of diacetyl, acetoin, 2- and 3-methylbutanol, 2- and 3-methylbutanal and 2...

  20. An Overview on the Effects of Sodium Benzoate as a Preservative in Food Products

    OpenAIRE

    Shahmohammadi; Javadi; Nassiri-Asl

    2016-01-01

    Context Food spoilage has been a common problem throughout history, and much of the spoilage is caused the activity of microorganisms or enzymatic reactions during the storage of food. Thus, using chemical substances could prevent or delay food spoilage and this has led to the great success of these compounds in the treatment of human diseases. Sodium benzoate is one of the synthetic additives that are widely used in the food industry. Evidenc...

  1. Comparison of three Bacillus amyloliquefaciens strains growth behaviour and evaluation of the spoilage risk during bread shelf-life.

    Science.gov (United States)

    Valerio, F; Di Biase, M; Huchet, V; Desriac, N; Lonigro, S L; Lavermicocca, P; Sohier, D; Postollec, F

    2015-02-01

    This study aims at the characterisation of growth behaviour of three strains of Bacillus amyloliquefaciens, isolated from ropy bread (ATCC8473), wheat grain (ISPA-S109.3) and semolina (ISPA-N9.1) to estimate rope spoilage risk in pan bread during shelf-life using the Sym'Previus tool. Cardinal values and growth/no growth boundaries were determined in broth, while artificial spore inoculations were performed in dough for various pan bread recipes to compare experimental counts with in silico growth simulations. Finally, two storage scenarios were tested to determine the probability to reach a spoilage threshold during bread shelf-life. Similarly to the safety criteria fixed for Listeria monocytogenes contamination in foodstuff complying with EC regulation, a potential rope spoilage threshold was arbitrary fixed at 5 log CFU/g for B. amyloliquefaciens. This study further underlines a higher rope spoilage potential of the ISPA strains as compared to the ATCC strain, thus emphasizing the interest to characterise both wild strains and reference strain to account for biological variability. In conclusion, this study showed that available decision making tools which are largely recognized to predict behaviour of pathogenic strains, shall also be used with spoilage strains to help maintain food quality and extend shelf-life. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. A standard bacterial isolate set for research on contemporary dairy spoilage.

    Science.gov (United States)

    Trmčić, A; Martin, N H; Boor, K J; Wiedmann, M

    2015-08-01

    Food spoilage is an ongoing issue that could be dealt with more efficiently if some standardization and unification was introduced in this field of research. For example, research and development efforts to understand and reduce food spoilage can greatly be enhanced through availability and use of standardized isolate sets. To address this critical issue, we have assembled a standard isolate set of dairy spoilers and other selected nonpathogenic organisms frequently associated with dairy products. This publicly available bacterial set consists of (1) 35 gram-positive isolates including 9 Bacillus and 15 Paenibacillus isolates and (2) 16 gram-negative isolates including 4 Pseudomonas and 8 coliform isolates. The set includes isolates obtained from samples of pasteurized milk (n=43), pasteurized chocolate milk (n=1), raw milk (n=1), cheese (n=2), as well as isolates obtained from samples obtained from dairy-powder production (n=4). Analysis of growth characteristics in skim milk broth identified 16 gram-positive and 13 gram-negative isolates as psychrotolerant. Additional phenotypic characterization of isolates included testing for activity of β-galactosidase and lipolytic and proteolytic enzymes. All groups of isolates included in the isolate set exhibited diversity in growth and enzyme activity. Source data for all isolates in this isolate set are publicly available in the FoodMicrobeTracker database (http://www.foodmicrobetracker.com), which allows for continuous updating of information and advancement of knowledge on dairy-spoilage representatives included in this isolate set. This isolate set along with publicly available isolate data provide a unique resource that will help advance knowledge of dairy-spoilage organisms as well as aid industry in development and validation of new control strategies. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  3. Preventing spoilage of poultry meat: focus on spoilage microorganisms and their control

    Science.gov (United States)

    The shelf-life of fresh poultry meat is determined by the level of contamination of processed meat by spoilage microorganisms, storage temperature and storage atmosphere. This chapter looks at the various ways by which to extend the shelf-life of poultry meat: vacuum and modified atmosphere packagin...

  4. Effect of different storage temperatures on bacterial spoilage of ...

    African Journals Online (AJOL)

    This study determined the bacterial organisms associated with Oreochromis niloticus spoilage at two storage temperatures (6 and 20°C) and also assessed the ability of the individual bacterial isolates to cause spoilage at the two storage temperatures. Bacteriological analysis revealed the association of five bacteria ...

  5. Mycology and spoilage of retail cashew nuts | Adebajo | African ...

    African Journals Online (AJOL)

    All the species recovered induced detectable loss in weights of the milled nuts, though to varying extents and would be expected to cause considerable spoilage of the nuts. Key words: Cashew nut, Anacardium occidentale, fungal count, mycology, Aspergillus sp., Penicillium sp., spoilage. African Journal of Biotechnology ...

  6. Bacterial spoilage of fresh meat in some selected Lagos markets ...

    African Journals Online (AJOL)

    A study of the bacteria associated with spoilage of fresh meat was carried out. The flora causing spoilage of meat include Alcaligenes liquefaciens, Bacillus subtilis, Clostridium perfringes, Escherichia coli, Klebsiella pneumoniae, Lactobacillus sp., Micrococcus varians, Pseudomonas aeruginosa, Sarcina sp. Serratia ...

  7. Food irradiation: An update

    International Nuclear Information System (INIS)

    Morrison, Rosanna M.

    1984-01-01

    Recent regulatory and commercial activity regarding food irradiation is highlighted. The effects of irradiation, used to kill insects and microorganisms which cause food spoilage, are discussed. Special attention is given to the current regulatory status of food irradiation in the USA; proposed FDA regulation regarding the use of irradiation; pending irradiation legislation in the US Congress; and industrial applications of irradiation

  8. Antibacterial Activity of Zataria multiflora Boiss Essential Oil against Some Fish Spoilage Bacteria

    Directory of Open Access Journals (Sweden)

    Mohammad Hashemi

    2017-09-01

    Full Text Available Background: The aim of this study was to investigate antimicrobial effect of Zataria multiflora Boiss essential oil (EO against six fish spoilage bacteria for evaluation of its potential utilization in the preservation of minimally processed fish products. Methods: Firstly, GC-MS analysis of the EO was performed to determine its chemical composition. Then, antibacterial effect of the EO in a range of 0.031 to 4 mg/ml was tested against different fish spoilage bacteria such as Aeromonas hydrophila, Pseudomonas aeruginosa, Pseudomonas fluorescens, Shewanella putrefaciens, Escherichia coli and Bacillus subtilis by broth microdilution method to determine minimum inhibitory (MIC and minimum bactericidal (MBC concentrations. Results: GC-MS results showed that phenolic components such as carvacrol (51.55% and thymol (25.49% were predominant constituents of the EO. Zataria multiflora Boiss EO exhibited strong antimicrobial activity against all tested bacteria. Shewanella Putrefaciens was the most sensitive bacteria with MBC value of 0. 5 mg/ml. Conclusion: According to the results, this EO could be used as an important natural alternative to prevent bacterial growth in food specially seafood products to preserve them against bacterial spoilage.

  9. EFFECT OF ELECTROMAGNETIC FIELD ON THE SPOILAGE FUNGI OF SOME SELECTED EDIBLE FRUITS IN SOUTHWESTERN, NIGERIA

    Directory of Open Access Journals (Sweden)

    Bamidele J. Akinyele

    2012-10-01

    Full Text Available The influence of electromagnetic field wave on the survival of spoilage fungi associated with some edible fruits consumed in southwestern, Nigeria was studied using cashew (Anacardium occidentale L., pineapple (Ananas comosus, carrot (Daucus carota, cucumber (Cucumis sativus, apple (Malus domestica and African star apple (Chrysophyllum africanum. The spoilage fungi used include the genera of Aspergillus, Penicillium, Articulospora, Mucor, Staphylotrichum, Bisbyopeltis, Fusarium, Rhizopus and a yeast, Saccharomyces cerevisiae. There was a general decrease in fungal growth as shown in the number of spores produced with increase in exposure time of isolates to electromagnetic field except in Articulospora inflata, Penicillium italicum and Mucor mucedo where there was stimulatory effect as there was increase in the fungal spores compared to the control. A decrease was also observed in growth of the fungal isolates with increase in the intensity of the electromagnetic field at voltage of 7 V to 10 V and from 10 V to 13 V. The highest percentage reduction was recorded by Bisbyopeltis phoebesii at intensity of voltage 13V after 60 minutes of exposure. Exposure of the fruits to electromagnetic field wave did not alter the nutrient components of the fruits as observed in the proximate and mineral contents of the treated and untreated fruits. The result of the study revealed that electromagnetic field wave has great potential for use in the control of fruits spoilage and food preservation.

  10. Mapping microbial ecosystems and spoilage-gene flow in breweries highlights patterns of contamination and resistance

    Science.gov (United States)

    Bokulich, Nicholas A; Bergsveinson, Jordyn; Ziola, Barry; Mills, David A

    2015-01-01

    Distinct microbial ecosystems have evolved to meet the challenges of indoor environments, shaping the microbial communities that interact most with modern human activities. Microbial transmission in food-processing facilities has an enormous impact on the qualities and healthfulness of foods, beneficially or detrimentally interacting with food products. To explore modes of microbial transmission and spoilage-gene frequency in a commercial food-production scenario, we profiled hop-resistance gene frequencies and bacterial and fungal communities in a brewery. We employed a Bayesian approach for predicting routes of contamination, revealing critical control points for microbial management. Physically mapping microbial populations over time illustrates patterns of dispersal and identifies potential contaminant reservoirs within this environment. Habitual exposure to beer is associated with increased abundance of spoilage genes, predicting greater contamination risk. Elucidating the genetic landscapes of indoor environments poses important practical implications for food-production systems and these concepts are translatable to other built environments. DOI: http://dx.doi.org/10.7554/eLife.04634.001 PMID:25756611

  11. Aerobic sugar metabolism in the spoilage yeast Zygosaccharomyces bailii.

    Science.gov (United States)

    Merico, Annamaria; Capitanio, Daniele; Vigentini, Ileana; Ranzi, Bianca Maria; Compagno, Concetta

    2003-12-01

    Despite the importance of some Zygosaccharomyces species as agents causing spoilage of food, the carbon and energy metabolism of most of them is yet largely unknown. This is the case with Zygosaccharomyces bailii. In this study the occurrence of the Crabtree effect in the petite-negative yeast Z. bailii ATCC 36947 was investigated. In this yeast the aerobic ethanol production is strictly dependent on the carbon source utilised. In glucose-limited continuous cultures a very low level of ethanol was produced. In fructose-limited continuous cultures ethanol was produced at a higher level and its production increased with the dilution rate. As a consequence, on fructose the onset of respiro-fermentative metabolism caused a reduction in biomass yield. An immediate aerobic alcoholic fermentation in Z. bailii was observed during the transition from sugar limitation to sugar excess, both on glucose and on fructose. The analysis of some key enzymes of the fermentative metabolism showed a high level of acetyl-CoA synthetase in Z. bailii growing on fructose. At high dilution rates, the activities of glucose- and fructose-phosphorylating enzymes, as well as of pyruvate decarboxylase and alcohol dehydrogenase, were higher in cells during growth on fructose than on glucose.

  12. Incorporation of nisin in natural casing for the control of spoilage microorganisms in vacuum packaged sausage

    OpenAIRE

    Barros,Joyce Regina de; Kunigk,Leo; Jurkiewicz,Cynthia Hyppolito

    2010-01-01

    This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1) 0.1% food grade phosphoric acid; 2) 5.0 mg/L nisin; 3)?0.1% phosphoric acid and 5.0 mg/L nisin; and 4) sterile water (control). The sausages were produced in a pilot plant, stuffed into the pretreated natural casings, vacuum packaged and stored at 4 and 10??C for 56 days...

  13. Synergistic effects of ethanolic plant extract mixtures against food ...

    African Journals Online (AJOL)

    QFB ALE

    2014-01-29

    Tayel and El-Tras, 2010). A variety of microorganisms also lead to food spoilage that is encountered as one of the most important matter con- cerning the food industry. So far, many pathogens micro- organisms have been ...

  14. Emerging Preservation Techniques for Controlling Spoilage and Pathogenic Microorganisms in Fruit Juices

    Directory of Open Access Journals (Sweden)

    Kamal Rai Aneja

    2014-01-01

    Full Text Available Fruit juices are important commodities in the global market providing vast possibilities for new value added products to meet consumer demand for convenience, nutrition, and health. Fruit juices are spoiled primarily due to proliferation of acid tolerant and osmophilic microflora. There is also risk of food borne microbial infections which is associated with the consumption of fruit juices. In order to reduce the incidence of outbreaks, fruit juices are preserved by various techniques. Thermal pasteurization is used commercially by fruit juice industries for the preservation of fruit juices but results in losses of essential nutrients and changes in physicochemical and organoleptic properties. Nonthermal pasteurization methods such as high hydrostatic pressure, pulsed electric field, and ultrasound and irradiations have also been employed in fruit juices to overcome the negative effects of thermal pasteurization. Some of these techniques have already been commercialized. Some are still in research or pilot scale. Apart from these emerging techniques, preservatives from natural sources have also shown considerable promise for use in some food products. In this review article, spoilage, pathogenic microflora, and food borne outbreaks associated with fruit juices of last two decades are given in one section. In other sections various prevention methods to control the growth of spoilage and pathogenic microflora to increase the shelf life of fruit juices are discussed.

  15. Development of nano-encapsulation systems for the food antifungal natamycin : Formulation, characterization and post-processing

    NARCIS (Netherlands)

    Bouaoud, C.

    2016-01-01

    Food spoilage has become in the last decades one of the biggest challenges faced by the food industry, with a significant amount of products thrown away at every step of the supply chain. Microbial contamination is listed as one of the major causes of food spoilage and can be at a large extent

  16. In vitro assessment of Pediococcus acidilactici Kp10 for its potential use in the food industry.

    Science.gov (United States)

    Abbasiliasi, Sahar; Tan, Joo Shun; Bashokouh, Fatemeh; Ibrahim, Tengku Azmi Tengku; Mustafa, Shuhaimi; Vakhshiteh, Faezeh; Sivasamboo, Subhashini; Ariff, Arbakariya B

    2017-05-23

    Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro. P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities. The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

  17. Bacterial spoilers of food: behavior, fitness and functional properties.

    Science.gov (United States)

    Remenant, Benoît; Jaffrès, Emmanuel; Dousset, Xavier; Pilet, Marie-France; Zagorec, Monique

    2015-02-01

    Most food products are highly perishable as they constitute a rich nutrient source for microbial development. Among the microorganisms contaminating food, some present metabolic activities leading to spoilage. In addition to hygienic rules to reduce contamination, various treatments are applied during production and storage to avoid the growth of unwanted microbes. The nature and appearance of spoilage therefore depend on the physiological state of spoilers and on their ability to resist the processing/storage conditions and flourish on the food matrix. Spoilage also relies on the interactions between the microorganisms composing the ecosystems encountered in food. The recent rapid increase in publicly available bacterial genome sequences, as well as the access to high-throughput methods, should lead to a better understanding of spoiler behavior and to the possibility of decreasing food spoilage. This review lists the main bacterial species identified as food spoilers, their ability to develop during storage and/or processing, and the functions potentially involved in spoilage. We have also compiled an inventory of the available genome sequences of species encompassing spoilage strains. Combining in silico analysis of genome sequences with experimental data is proposed in order to understand and thus control the bacterial spoilage of food better. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Characterization of the spoilage lactic acid bacteria in "sliced vacuum-packed cooked ham".

    Science.gov (United States)

    Kalschne, Daneysa Lahis; Womer, Rute; Mattana, Ademir; Sarmento, Cleonice Mendes Pereira; Colla, Luciane Maria; Colla, Eliane

    2015-03-01

    The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples.

  19. Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

    Science.gov (United States)

    Kalschne, Daneysa Lahis; Womer, Rute; Mattana, Ademir; Sarmento, Cleonice Mendes Pereira; Colla, Luciane Maria; Colla, Eliane

    2015-01-01

    The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc / Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus , following by Lactobacillus sakei and Leuconostoc mesentereoides ; the Enterococcus sp. was not present in the samples. PMID:26221105

  20. Controlling Brochothrix thermosphacta as a spoilage risk using in-package atmospheric cold plasma.

    Science.gov (United States)

    Patange, Apurva; Boehm, Daniela; Bueno-Ferrer, Carmen; Cullen, P J; Bourke, Paula

    2017-09-01

    Brochothrix thermosphacta is the predominant spoilage microorganism in meat and its control in processing environments is important to maintain meat product quality. Atmospheric cold plasma is of interest for control of pathogenic and spoilage microorganisms in foods. This study ascertained the potential of dielectric barrier discharge atmospheric cold plasma (DBD-ACP) for control of B. thermosphacta, taking microbial and food environment factors into consideration, and investigated the shelf-life of lamb chop after in-package plasma treatment in modified atmosphere. Community profiling was used to assess the treatment effects on the lamb microflora. ACP treatment (80 kV) for 30s inactivated B. thermosphacta populations below detection levels in PBS, while 5 min treatment achieved a 2 Log cycle reduction using a complex meat model medium and attached cells. The antimicrobial efficacy of plasma was reduced but still apparent on lamb chop surface-inoculated with high concentrations of B. thermosphacta. Lamb chop treated under modified atmosphere exhibited reduced microbial growth over the product shelf-life and community profiling showed no evident changes to the microbial populations after the treatment. The overall results indicated potential of ACP to enhance microbial control leading to meat storage life extension through adjusting the modality of treatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Characterization of the spoilage lactic acid bacteria in “sliced vacuum-packed cooked ham”

    Directory of Open Access Journals (Sweden)

    Daneysa Lahis Kalschne

    2015-03-01

    Full Text Available The lactic acid bacteria are involved with food fermentation and in such cases with food spoilage. Considering the need to reduce the lactic acid bacteria growth in meat products, the aim of this work was to enumerated and investigated the lactic acid bacteria present on sliced vacuum-packed cooked ham stored at 4 °C and 8 °C for 45 days by phenotypic and molecular techniques. The quantification showed that the lactic acid bacteria were present from the first day with mean count of 1.98 log cfu/g for the four batches analyzed. The lactic acid bacteria grew rapidly on the samples, and plate counts around 7.59 log cfu/g and 8.25 log cfu/g were detected after 45 days of storage at 4 °C and 8 °C, respectively; storage temperatures studied showed significant influence on the microorganism in study growth. The predominant lactic acid bacteria associated with the spoilage samples at one day of storage includes Lactobacillus sp., the phenotypic overlap Leuconostoc/Weissella sp. and Enterococcus sp. At 45 days of storage at 4 and 8 °C the mainly specie was Lactobacillus curvatus, following by Lactobacillus sakei and Leuconostoc mesentereoides; the Enterococcus sp. was not present in the samples.

  2. Well-known quorum sensing inhibitors do not affect bacterial quorum sensing-regulated bean sprout spoilage.

    Science.gov (United States)

    Rasch, M; Rasmussen, T B; Andersen, J B; Persson, T; Nielsen, J; Givskov, M; Gram, L

    2007-03-01

    To investigate the potential of quorum sensing inhibitors (QSI) as food preservative agents in a food product, where bacterial spoilage is controlled by quorum sensing (QS). The effects of well-known QSI were tested on spoilage phenotypes and on QS-regulated genes of a bean sprout spoiling bacterial isolate (Pectobacterium A2JM) in laboratory substrates and in a bean sprout model system. The acylated homoserine lactones (AHL) analogues PenS-AHL and HepS-AHL decreased the specific protease activity of Pectobacterium A2JM in broth but did not reduce the expression of a QS-regulated secretion protein, and were without effect on soft rot of bean sprouts. The QSI ProS-AHL, furanone C-30, patulin, penicillic acid and 4-nitropyridine-N-oxide did not have any effect on protease activity, on gene expression or bean sprout appearance at nongrowth inhibitory concentrations. Extracts from garlic and bean sprouts induced the QS system of Pectobacterium in bean sprouts and a broth system, respectively. Among the several well-known QSI compounds, only PenS-AHL and HepS-AHL, inhibited QS-regulated protease activity of Pectobacterium A2JM in broth cultures, but had no effect on bean sprout spoilage. The QSI compounds must be selected in the specific system in which they are to function and they cannot easily be transferred from one QS system to another.

  3. Effects of water activity on the performance of potassium sorbate and natamycin as preservatives against cheese spoilage moulds

    Directory of Open Access Journals (Sweden)

    Marín P.

    2017-10-01

    Full Text Available This work investigated the effects of the food preservatives potassium sorbate and natamycin, combined with different levels of ionic (sodium chloride and non-ioinic (glycerol water activity (aw, on growth of fungi involved in cheese spoilage. In general, the combined effect of water stress and presence of preservatives enhanced fungal inhibition. However, some doses of potassium sorbate (0.02% and natamycin (1, 5 and 10 ppm were able to stimulate growth of Aspergillus varians, Mucor racemosus, Penicillium chrysogenum and P. roqueforti at aw values in the range of 0.93–0.97. P. solitum was the only species whose growth was consistently reduced by any doses of preservative. The results also showed that sodium chloride and glycerol differentially affected the efficacy of preservatives. This study indicates that aw of cheese is a critical parameter to be considered in the formulation of preservative coatings used against fungal spoilage.

  4. Acetic acid bacteria spoilage of bottled red wine -- a review.

    Science.gov (United States)

    Bartowsky, Eveline J; Henschke, Paul A

    2008-06-30

    Acetic acid bacteria (AAB) are ubiquitous organisms that are well adapted to sugar and ethanol rich environments. This family of Gram-positive bacteria are well known for their ability to produce acetic acid, the main constituent in vinegar. The oxidation of ethanol through acetaldehyde to acetic acid is well understood and characterised. AAB form part of the complex natural microbial flora of grapes and wine, however their presence is less desirable than the lactic acid bacteria and yeast. Even though AAB were described by Pasteur in the 1850s, wine associated AAB are still difficult to cultivate on artificial laboratory media and until more recently, their taxonomy has not been well characterised. Wine is at most risk of spoilage during production and the presence of these strictly aerobic bacteria in grape must and during wine maturation can be controlled by eliminating, or at least limiting oxygen, an essential growth factor. However, a new risk, spoilage of wine by AAB after packaging, has only recently been reported. As wine is not always sterile filtered prior to bottling, especially red wine, it often has a small resident bacterial population (wines, sealed with natural cork closures, and stored in a vertical upright position may develop spoilage by acetic acid bacteria. This spoilage is evident as a distinct deposit of bacterial biofilm in the neck of the bottle at the interface of the wine and the headspace of air, and is accompanied with vinegar, sherry, bruised apple, nutty, and solvent like off-aromas, depending on the degree of spoilage. This review focuses on the wine associated AAB species, the aroma and flavour changes in wine due to AAB metabolism, discusses the importance of oxygen ingress into the bottle and presents a hypothesis for the mechanism of spoilage of bottled red wine.

  5. Meat spoilage: a critical review of a neglected alteration due to ropy slime producing bacteria

    Directory of Open Access Journals (Sweden)

    Maria F. Iulietto

    2015-07-01

    Full Text Available The shelf-life of a product is the period of time during which the food retains its qualitative characteristics. Bacteria associated with meat spoilage produce unattractive odours and flavours, discolouration, gas and slime. There are several neglected alterations that deserve more attention from food business operators and competent authorities. Ropy slime is a typical alteration of the surface of vacuum and modified atmosphere packed cooked meat products, that causes major economic losses due to the increasingly sophisticated consumer requirements. This is a review article that aims at raising awareness of an old problem of new concern, in the light of new advances and trends for understanding the aetiology of the phenomenon, the origins of contamination and the prevention measures.

  6. Zygosaccharomyces lentus: a significant new osmophilic, preservative-resistant spoilage yeast, capable of growth at low temperature.

    Science.gov (United States)

    Steels, H; James, S A; Roberts, I N; Stratford, M

    1999-10-01

    Zygosaccharomyces lentus is a yeast species recently identified from its physiology and 18S ribosomal sequencing (Steels et al. 1999).The physiological characteristics of five strains of this new yeast so far isolated were investigated, particularly those of technical significance for a spoilage yeast, namely temperature range, pH range, osmotolerance, sugar fermentation, resistance to food preservatives such as sorbic acid, benzoic acid and dimethyldicarbonate (DMDC; Velcorin). Adaptation to benzoic acid, and growth in shaking and static culture were also investigated. Zygosaccharomyces lentus strains grew over a wide range of temperature (4-25 degrees C) and pH 2.2-7.0. Growth at 4 degrees C was significant. Zygosaccharomyces lentus strains grew at 25-26 degrees C in static culture but were unable to grow in aerobic culture close to their temperature maximum. All Z. lentus strains grew in 60% w/v sugar and consequently, are osmotolerant. Zygosaccharomyces lentus strains could utilize sucrose, glucose or fructose as a source of fermentable sugar, but not galactose. Zygosaccharomyces lentus strains were resistant to food preservatives, growing in sorbic acid up to 400 mg l-1 and benzoic acid to 900 mg l-1 at pH 4.0. Adaptation to higher preservative concentrations was demonstrated with benzoic acid. Resistance to DMDC was shown to be greater than that of Z. bailii and Saccharomyces cerevisiae. This study confirms that Z. lentus is an important food spoilage organism potentially capable of growth in a wide range of food products, particularly low pH, high sugar foods and drinks. It is likely to be more significant than Z. bailii in the spoilage of chilled products.

  7. Toxigenic genes, spoilage potential, and antimicrobial resistance of Bacillus cereus group strains from ice cream.

    Science.gov (United States)

    Arslan, Seza; Eyi, Ayla; Küçüksarı, Rümeysa

    2014-02-01

    Bacillus spp. can be recovered from almost every environment. It is also found readily in foods, where it may cause food spoilage and/or food poisoning due to its toxigenic and pathogenic nature, and extracellular enzymes. In this study, 29 Bacillus cereus group strains from ice cream were examined for the presence of following virulence genes hblC, nheA, cytK and ces genes, and tested for a range of the extracellular enzymes, and antimicrobial susceptibility. The strains were found to produce extracellular enzymes: proteolytic and lipolytic activity, gelatin hydrolysis and lecithinase production (100%), DNase production (93.1%) and amylase activity (93.1%). Of 29 strains examined, 24 (82.8%) showed hemolytic activity on blood agar. Beta-lactamase enzyme was only produced by 20.7% of B. cereus group. Among 29 B. cereus group from ice cream, nheA was the most common virulence gene detected in 44.8% of the strains, followed by hblC gene with 17.2%. Four (13.8%) of the 29 strains were positive for both hblC gene and nheA gene. Contrarily, cytK and ces genes were not detected in any of the strains. Antimicrobial susceptibility of ice cream isolates was tested to 14 different antimicrobial agents using the disc diffusion method. We detected resistance to penicillin and ampicillin with the same rate of 89.7%. Thirty-one percent of the strains were multiresistant to three or more antibiotics. This study emphasizes that the presence of natural isolates of Bacillus spp. harboring one or more enterotoxin genes, producing extracellular enzymes which may cause spoilage and acquiring antibiotic resistance might hold crucial importance in the food safety and quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Extreme resistance to weak-acid preservatives in the spoilage yeast Zygosaccharomyces bailii☆

    Science.gov (United States)

    Stratford, Malcolm; Steels, Hazel; Nebe-von-Caron, Gerhard; Novodvorska, Michaela; Hayer, Kimran; Archer, David B.

    2013-01-01

    Weak-acid preservatives, such as sorbic acid and acetic acid, are used in many low pH foods to prevent spoilage by fungi. The spoilage yeast Zygosaccharomyces bailii is notorious for its extreme resistance to preservatives and ability to grow in excess of legally-permitted concentrations of preservatives. Extreme resistance was confirmed in 38 strains of Z. bailii to several weak-acid preservatives. Using the brewing yeast Saccharomyces cerevisiae as a control, tests showed that Z. bailii was ~ 3-fold more resistant to a variety of weak-acids but was not more resistant to alcohols, aldehydes, esters, ethers, ketones, or hydrophilic chelating acids. The weak acids were chemically very diverse in structure, making it improbable that the universal resistance was caused by degradation or metabolism. Examination of Z. bailii cell populations showed that extreme resistance to sorbic acid, benzoic acid and acetic acid was limited to a few cells within the population, numbers decreasing with concentration of weak acid to bailii is due to population heterogeneity, with a small proportion of cells having a lower intracellular pH. This reduces the level of accumulation of any weak acid in the cytoplasm, thus conferring resistance to all weak acids, but not to other inhibitors. PMID:23856006

  9. Extreme resistance to weak-acid preservatives in the spoilage yeast Zygosaccharomyces bailii.

    Science.gov (United States)

    Stratford, Malcolm; Steels, Hazel; Nebe-von-Caron, Gerhard; Novodvorska, Michaela; Hayer, Kimran; Archer, David B

    2013-08-16

    Weak-acid preservatives, such as sorbic acid and acetic acid, are used in many low pH foods to prevent spoilage by fungi. The spoilage yeast Zygosaccharomyces bailii is notorious for its extreme resistance to preservatives and ability to grow in excess of legally-permitted concentrations of preservatives. Extreme resistance was confirmed in 38 strains of Z. bailii to several weak-acid preservatives. Using the brewing yeast Saccharomyces cerevisiae as a control, tests showed that Z. bailii was ~3-fold more resistant to a variety of weak-acids but was not more resistant to alcohols, aldehydes, esters, ethers, ketones, or hydrophilic chelating acids. The weak acids were chemically very diverse in structure, making it improbable that the universal resistance was caused by degradation or metabolism. Examination of Z. bailii cell populations showed that extreme resistance to sorbic acid, benzoic acid and acetic acid was limited to a few cells within the population, numbers decreasing with concentration of weak acid to bailii is due to population heterogeneity, with a small proportion of cells having a lower intracellular pH. This reduces the level of accumulation of any weak acid in the cytoplasm, thus conferring resistance to all weak acids, but not to other inhibitors. © 2013. Published by Elsevier B.V. All rights reserved.

  10. The Occurrence of Beer Spoilage Lactic Acid Bacteria in Craft Beer Production.

    Science.gov (United States)

    Garofalo, Cristiana; Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Aquilanti, Lucia; Clementi, Francesca

    2015-12-01

    Beer is one of the world's most ancient and widely consumed fermented alcoholic beverages produced with water, malted cereal grains (generally barley and wheat), hops, and yeast. Beer is considered an unfavorable substrate of growth for many microorganisms, however, there are a limited number of bacteria and yeasts, which are capable of growth and may spoil beer especially if it is not pasteurized or sterile-filtered as craft beer. The aim of this research study was to track beer spoilage lactic acid bacteria (LAB) inside a brewery and during the craft beer production process. To that end, indoor air and work surface samples, collected in the brewery under study, together with commercial active dry yeasts, exhausted yeasts, yeast pellet (obtained after mature beer centrifugation), and spoiled beers were analyzed through culture-dependent methods and PCR-DGGE in order to identify the contaminant LAB species and the source of contamination. Lactobacillus brevis was detected in a spoiled beer and in a commercial active dry yeast. Other LAB species and bacteria ascribed to Staphylococcus sp., Enterobaceriaceae, and Acetobacter sp. were found in the brewery. In conclusion, the PCR-DGGE technique coupled with the culture-dependent method was found to be a useful tool for identifying the beer spoilage bacteria and the source of contamination. The analyses carried out on raw materials, by-products, final products, and the brewery were useful for implementing a sanitization plan to be adopted in the production plant. © 2015 Institute of Food Technologists®

  11. Spoilage of vegetable crops by bacteria and fungi and related health hazards.

    Science.gov (United States)

    Tournas, V H

    2005-01-01

    After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. The most common bacterial agents are Erwinia carotovora, Pseudomonas spp., Corynebacterium, Xanthomonas campestris, and lactic acid bacteria with E. carotovora being the most common, attacking virtually every vegetable type. Fungi commonly causing spoilage of fresh vegetables are Botrytis cinerea, various species of the genera Alternaria, Aspergillus, Cladosporium, Colletotrichum, Phomopsis, Fusarium, Penicillium, Phoma, Phytophthora, Pythium and Rhizopus spp., Botrytis cinerea, Ceratocystis fimbriata, Rhizoctonia solani, Sclerotinia sclerotiorum, and some mildews. A few of these organisms show a substrate preference whereas others such as Botrytis cinerea, Colletotrichum, Alternaria, Cladosporium, Phytophthora, and Rhizopus spp., affect a wide variety of vegetables causing devastating losses. Many of these agents enter the plant tissue through mechanical or chilling injuries, or after the skin barrier has been broken down by other organisms. Besides causing huge economic losses, some fungal species could produce toxic metabolites in the affected sites, constituting a potential health hazard for humans. Additionally, vegetables have often served as vehicles for pathogenic bacteria, viruses, and parasites and were implicated in many food borne illness outbreaks. In order to slow down vegetable spoilage and minimize the associated adverse health effects, great caution should be taken to follow strict hygiene, good agricultural practices (GAPs) and good manufacturing practices (GMPs) during cultivation, harvest, storage, transport, and marketing.

  12. Bacterial spoilage of meat and cured meat products

    NARCIS (Netherlands)

    Borch, E.; Kant-Muermans, M.L.T.; Blixt, Y.

    1996-01-01

    The influence of environmental factors (product composition and storage conditions) on the selection, growth rate and metabolic activity of the bacterial flora is presented for meat (pork and beef) and cooked, cured meat products. The predominant bacteria associated with spoilage of refrigerated

  13. Volatile components associated with bacterial spoilage of tropical prawns

    DEFF Research Database (Denmark)

    Chinivasagam, H.N.; Bremner, Allan; Wood, A.F.

    1998-01-01

    , whereas sulphides and amines occurred whether the predominant spoilage organism was Ps.fragi or Shewanella putrefaciens. The free amino acid profiles of banana and king prawns were high in arginine (12-14%) and low in cysteine (0.1-0.17%) and methionine (0.1-0.2%). Filter sterilised raw banana prawn broth...

  14. Spoilage potential of Paenibacillussp. in Brazilian raw milk

    Directory of Open Access Journals (Sweden)

    José Carlos Ribeiro Júnior

    2016-04-01

    Full Text Available ABSTRACT: Bacterial spores are widespread in the environment and can contaminate milk. Spores are resistant to thermal conditions and your germination reduces milk shelf-life because the aerobic bacteria that are sporulated produce proteases and lipases. The aim of this study was identify Paenibacillus sp., the spoilage microbiota, arising from the germination of spores in raw milk and your spoilage potential. Twenty different milk samples were treated at 80°C/12min and plated to isolate spore-forming bacteria. These strains were picked in milk agar and tributyrin agar for verification of their potential proteolytic and lipolytic activities, respectively. Amplification and sequencing of the 16S rRNA gene of the strains for identification by similarity to the DNA sequences deposited in GenBank was performed. One hundred and thirty-seven isolates were obtained, of which 40 (29.2% showed spoilage activity for milk. Of these, three (7.5% were identified as strains of Paenibacillus sp., and all were lipolytic. Paenibacillus sp. have been identified as primarily responsible for the spoilage of pasteurized milk with a long shelf-life in other countries. To increase the shelf-life of Brazilian pasteurized milk, it is important to identify the sporulated microbes to determine their origin and to control the contamination of milk by vegetative forms such as spores.

  15. Spoilage fungi and their mycotoxins in commercially marketed chestnuts

    DEFF Research Database (Denmark)

    Overy, David Patrick; Seifert, K.A.; Savard, M.E.

    2003-01-01

    A nationwide survey was carried out to assess mould spoilage of Castanea sativa nuts sold in Canadian grocery stores in 1998-99. Morphological and cultural characters, along with secondary metabolite profiles derived from thin-layer chromatography, were used to sort and identify fungi cultured from...

  16. Using Multispectral Imaging for Spoilage Detection of Pork Meat

    DEFF Research Database (Denmark)

    Dissing, Bjørn Skovlund; Papadopoulou, Olga S.; Tassou, Chrysoula

    2013-01-01

    different storage conditions: aerobic and modified atmosphere packages as well as under different temperatures. Besides bacterial counts, a sensory panel has judged the spoilage degree of all meat samples into one of three classes. Results showed that the multispectral imaging device was able to classify 76...

  17. Metabolic strategies of beer spoilage lactic acid bacteria in beer.

    Science.gov (United States)

    Geissler, Andreas J; Behr, Jürgen; von Kamp, Kristina; Vogel, Rudi F

    2016-01-04

    Beer contains only limited amounts of readily fermentable carbohydrates and amino acids. Beer spoilage lactic acid bacteria (LAB) have to come up with metabolic strategies in order to deal with selective nutrient content, high energy demand of hop tolerance mechanisms and a low pH. The metabolism of 26 LAB strains of 6 species and varying spoilage potentialwas investigated in order to define and compare their metabolic capabilities using multivariate statistics and outline possible metabolic strategies. Metabolic capabilities of beer spoilage LAB regarding carbohydrate and amino acids did not correlate with spoilage potential, but with fermentation type (heterofermentative/homofermentative) and species. A shift to mixed acid fermentation by homofermentative (hof) Pediococcus claussenii and Lactobacillus backii was observed as a specific feature of their growth in beer. For heterofermentative (hef) LAB a mostly versatile carbohydrate metabolism could be demonstrated, supplementing the known relevance of organic acids for their growth in beer. For hef LAB a distinct amino acid metabolism, resulting in biogenic amine production, was observed, presumably contributing to energy supply and pH homeostasis.

  18. 18 Evaluation of Microbial Spoilage of Some Aquacultured Fresh ...

    African Journals Online (AJOL)

    `123456789jkl''''#

    autolytic and chemical spoilage (oxidative rancidity) of which microbiological contamination has been noted as the main cause of fish deterioration. Initial microflora on the surface of the fish is directly related to the surrounding aquatic environment while the bacterial flora in the gastrointestinal tract corresponds to the type of ...

  19. Salad dressing spoilage by Bacillus amyloliquefaciens with gas formation

    Directory of Open Access Journals (Sweden)

    Karen Signori Pereira

    2017-11-01

    Full Text Available Abstract B. amyloliquefaciens is a Gram-positive, aerobic, motile rod, often found in soil, which has been described as a plant growth promoter and is used in several industrial processes. This study reports an episode involving the gassy spoilage of salad dressing caused by B. amyloliquefaciens in a production facility located in Rio de Janeiro, Brazil. Nine B. amyloliquefaciens strains were isolated from spoiled salad dressings, the sugar used as a raw material in the manufacture and from the production plant. A genotypic analysis of the isolates by Rep-PCR generated eight band profiles grouped in five Rep-PCR clusters. When re-inoculated into fresh salad dressing three B. amyloliquefaciens isolates belonging to the Rep-PCR clusters A, D and E were able to reproduce the gassy spoilage process, whereas the isolates belonging to the Rep-PCR clusters B and C did not produce any visible spoilage, suggesting that these isolates were not directly involved in the spoilage process. The predominant Rep-PCR cluster, cluster A, included strains isolated from barbecue and passion fruit seed salad dressings and from sugar (raw material, suggesting it is a common source of contamination for such salad dressings.

  20. Controlling Blown Pack Spoilage Using Anti-Microbial Packaging.

    Science.gov (United States)

    Reid, Rachael; Bolton, Declan; Tiuftin, Andrey A; Kerry, Joe P; Fanning, Séamus; Whyte, Paul

    2017-08-12

    Active (anti-microbial) packaging was prepared using three different formulations; Auranta FV; Inbac-MDA and sodium octanoate at two concentrations (2.5 and 3.5 times their minimum inhibitory concentration (MIC, the lowest concentration that will inhibit the visible growth of the organisms) against Clostridium estertheticum , DSMZ 8809). Inoculated beef samples were packaged using the active packaging and monitored for 100 days storage at 2 °C for blown pack spoilage. The time to the onset of blown pack spoilage was significantly ( p < 0.01) increased using Auranta FV and sodium octanoate (caprylic acid sodium salt) at both concentrations. Moreover, sodium octanoate packs had significantly ( p < 0.01) delayed blown pack spoilage as compared to Auranta FV. It was therefore concluded that Auranta FV or sodium octanoate, incorporated into the packaging materials used for vacuum packaged beef, would inhibit blown pack spoilage and in the case of the latter, well beyond the 42 days storage period currently required for beef primals.

  1. Microorganisms associated with the spoilage of avocado pear ...

    African Journals Online (AJOL)

    The microorganisms associated with the spoilage of Avocado pear, Persea americana fruits, purchased fresh from various markets in Benin City were investigated. The pour plate method was used for the isolation. A total of nine species of microorganisms were isolated and identified in this study. They comprise of seven ...

  2. Identification and growth dynamics of meat spoilage microorganisms in modified atmosphere packaged poultry meat by MALDI-TOF MS.

    Science.gov (United States)

    Höll, Linda; Behr, Jürgen; Vogel, Rudi F

    2016-12-01

    Modified atmosphere packaging (MAP) is widely used in food industry to extend the microbiological shelf-life of meat. Typically, poultry meat has been packaged in a CO2/N2 atmosphere (with residual low O2). Recently, some producers use high O2 MAP for poultry meat to empirically reach comparable shelf lifes. In this work, we compared spoilage microbiota of skinless chicken breast in high (80% O2, 20% CO2) and low O2 MAP (65% N2 and 35% CO2). Two batches of meat were incubated in each atmosphere for 14 days at 4 °C and 10 °C. Atmospheric composition of each pack and colony forming units (25 °C, 48 h, BHI agar) of poultry samples were determined at seven timepoints. Identification of spoilage organisms was carried out by MALDI-TOF MS. Brochothrix thermosphacta, Carnobacterium sp. and Pseudomonas sp. were the main organisms found after eight days at 4 °C and 10 °C in high O2 MAP. In low O2 MAP, the main spoilage microbiota was represented by species Hafnia alvei at 10 °C, and genera Carnobacterium sp., Serratia sp., and Yersinia sp. at 4 °C. High O2 MAP is suggested as preferential gas because were less detrimental and pathogens like Yersinia were not observed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage

    Directory of Open Access Journals (Sweden)

    Ziola Barry

    2009-09-01

    Full Text Available Abstract Background Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol. Use of antimicrobial compounds (e.g., hop-compounds, Penicillin by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Results Lactic acid bacteria susceptibility test broth medium (LSM used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Conclusion Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

  4. Susceptibility of Pediococcus isolates to antimicrobial compounds in relation to hop-resistance and beer-spoilage.

    Science.gov (United States)

    Haakensen, Monique; Vickers, David M; Ziola, Barry

    2009-09-07

    Though important in the context of food microbiology and as potential pathogens in immuno-compromised humans, bacterial isolates belonging to the genus Pediococcus are best known for their association with contamination of ethanol fermentation processes (beer, wine, or fuel ethanol). Use of antimicrobial compounds (e.g., hop-compounds, Penicillin) by some industries to combat Pediococcus contaminants is long-standing, yet knowledge about the resistance of pediococci to antimicrobial agents is minimal. Here we examined Pediococcus isolates to determine whether antibiotic resistance is associated with resistance to hops, presence of genes known to correlate with beer spoilage, or with ability to grow in beer. Lactic acid bacteria susceptibility test broth medium (LSM) used in combination with commercially available GPN3F antimicrobial susceptibility plates was an effective method for assessing antimicrobial susceptibility of Pediococcus isolates. We report the finding of Vancomycin-susceptible Pediococcus isolates from four species. Interestingly, we found that hop-resistant, beer-spoilage, and beer-spoilage gene-harbouring isolates had a tendency to be more susceptible, rather than more resistant, to antimicrobial compounds. Our findings indicate that the mechanisms involved in conferring hop-resistance or ability to spoil beer by Pediococcus isolates are not associated with resistance to antibiotics commonly used for treatment of human infections. Also, Vancomycin-resistance was found to be isolate-specific and not intrinsic to the genus as previously believed.

  5. Carnobacterium divergens - a dominating bacterium of pork meat juice.

    Science.gov (United States)

    Rieder, Gabriele; Krisch, Linda; Fischer, Harald; Kaufmann, Maria; Maringer, Adolf; Wessler, Silja

    2012-07-01

    Nonspoiled food that nevertheless contains bacterial pathogens constitutes a much more serious health problem than spoiled food, as the consumer is not warned beforehand. However, data on the diversity of bacterial species in meat juice are rare. To study the bacterial load of fresh pork from ten different distributors, we applied a combination of the conventional culture-based and molecular methods for detecting and quantifying the microbial spectrum of fresh pork meat juice samples. Altogether, we identified 23 bacterial species of ten different families analyzed by 16S rRNA gene sequencing. The majority of isolates were belonging to the typical spoilage bacterial population of lactic acid bacteria (LAB), Enterococcaceae, and Pseudomonadaceae. Several additional isolates were identified as Staphylococcus spp. and Bacillus spp. originating from human and animal skin and other environmental niches including plants, soil, and water. Carnobacterium divergens, a LAB contributing to the spoilage of raw meat even at refrigeration temperature, was the most frequently isolated species in our study (5/10) with a bacterial load of 10(3) - 10(7) CFU mL(-1). In several of the analyzed pork meat juice samples, two bacterial faecal indicators, Serratia grimesii and Serratia proteamaculans, were identified together with another opportunistic food-borne pathogen, Staphylococcus equorum. Our data reveal a high bacterial load of fresh pork meat supporting the potential health risk of meat juice for the end consumer even under refrigerated conditions. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  6. Antimicrobial activity of different sodium and potassium salts of carboxylic acid against some common foodborne pathogens and spoilage-associated bacteria.

    Science.gov (United States)

    Cabezas-Pizarro, Jorge; Redondo-Solano, Mauricio; Umaña-Gamboa, Christian; Arias-Echandi, María Laura

    Cleaning and disinfection represent the most important activities associated with the elimination of dirt and microorganisms at food processing plants. Improper procedures may lead to cross contamination of food leading to its spoilage or even the transmission of foodborne pathogens. Several strategies have been used in order to achieve a good disinfection of surfaces and products; nevertheless, microbial resistance to common-use-products has developed lately. Due to this fact, the development of new non-toxic-food compatible chemical agents that reduce the impact of foodborne pathogens and spoilage causing microorganisms is desirable for the food industry. The objective of the present study was to evaluate the antimicrobial activity of different sodium and potassium salts of aliphatic and aromatic carboxylic acid on the growth of common food spoilage and pathogenic microorganisms. Growth curves were determined for Leuconostoc mesenteroides, Lactobacillus plantarum, Enterococcus faecalis, Candida albicans, Pseudomonas aeruginosa, Salmonella Enteritidis, and Listeria monocytogenes in contact with different concentrations of carboxylic acid salts. The inhibitory effect of both aliphatic and aromatic carboxylic acid salts, in accordance with concentration levels, was 100>50>25mg/ml. The inhibitory effect of aliphatic salts was butanoic>hexanoic> octanoic>decanoic and, benzoic>gallic>caffeic acid salts for aromatic salts. In general, sodium salts were more inhibitory than potassium salts (p≤0.05). Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Combination irradiation treatments for food safety and phytosanitary uses

    Science.gov (United States)

    Combination of irradiation treatment with other preservation techniques is of potential importance in enhancing the effectiveness and reducing the energy or dose requirement for destroying food borne illness and spoilage organisms while retaining or improving product quality. Phytosanitary irradiati...

  8. Activity of R(+) limonene on the maximum growth rate of fish spoilage organisms and related effects on shelf-life prolongation of fresh gilthead sea bream fillets.

    Science.gov (United States)

    Giarratana, Filippo; Muscolino, Daniele; Beninati, Chiara; Ziino, Graziella; Giuffrida, Alessandro; Panebianco, Antonio

    2016-11-21

    R(+)limonene (LMN) is the major aromatic compound in essential oils obtained from oranges, grapefruits, and lemons. The improvement of preservation techniques to reduce the growth and activity of spoilage microorganisms in foods is crucial to increase their shelf life and to reduce the losses due to spoilage. The aim of this work is to evaluate the effect of LMN on the shelf life of fish fillets. Its effectiveness was preliminarily investigated in vitro against 60 strains of Specific Spoilage Organisms (SSOs) and then on gilt-head sea bream fillets stored at 2±0.5°C for 15days under vacuum. LMN showed a good inhibitory effect against tested SSOs strains. On gilt-head sea bream fillets, LMN inhibited the growth SSOs effectively, and its use resulted in a shelf-life extension of ca. 6-9days of treated fillets, compared to the control samples. The LMN addition in Sparus aurata fillets giving a distinctive smell and like-lemon taste to fish fillets that resulted pleasant to panellists. Its use contributed to a considerable reduction of fish spoilage given that the fillets treated with LMN were still sensory acceptable after 15days of storage. LMN may be used as an effective antimicrobial system to reduce the microbial growth and to improve the shelf life of fresh gilt-head sea bream fillets. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. Antimicrobial Effect of Filipendula ulmaria Plant Extract Against Selected Foodborne Pathogenic and Spoilage Bacteria in Laboratory Media, Fish Flesh and Fish Roe Product

    Directory of Open Access Journals (Sweden)

    Charalampos Proestos

    2011-01-01

    Full Text Available Water-methanol extract from Filipendula ulmaria contains a variety of phenolic compounds, such as caffeic, p-coumaric and vanillic acid, myricetin, etc, which demonstrate antibacterial activity. Monitoring this activity in the broth using absorbance measurements showed that species of the Enterobacteriaceae family were more resistant than other Gram-negative and Gram-positive bacteria tested. Acidic environment enhanced the antibacterial activity of Filipendula ulmaria extract when it was tested against Salmonella Enteritidis PT4 and Listeria monocytogenes Scott A. The efficacy of Filipendula ulmaria extract against selected foodborne psychrotrophic bacteria was also tested using solid laboratory media and low incubation temperatures for better simulation of food preservation conditions. Higher concentrations of the extract, compared to minimum inhibitory concentration determined in the broth, were needed for satisfactory inhibition of spoilage bacteria. Potential use of Filipendula ulmaria extract as natural food preservative was also examined against natural spoilage flora and inoculated pathogenic bacteria on fish flesh and fish roe product (tarama salad. No significant differences of viable populations of spoilage or pathogenic bacteria were found between the treated samples and controls. Further trials of Filipendula ulmaria extract should be carried out in acidic foods with low fat and protein content, supplemented with additional adjuncts, in order to explore its potential as effective natural food antimicrobial agent.

  10. Development of detection medium for hard-to-culture beer-spoilage lactic acid bacteria.

    Science.gov (United States)

    Suzuki, K; Asano, S; Iijima, K; Kuriyama, H; Kitagawa, Y

    2008-05-01

    To develop a detection medium for hard-to-culture beer-spoilage lactic acid bacteria (LAB). Four hard-to-culture beer-spoilage strains of LAB, belonging to Lactobacillus paracollinoides and Lactobacillus lindneri, have been obtained by repeatedly subculturing the wild-type strains in beer. To develop a countermeasure against these hard-to-culture beer-spoilage LAB, a beer-based medium was modified. As a consequence, the supplementation of a small amount of de Man Rogosa Sharpe medium was found to enhance the growth of hard-to-culture beer-spoilage LAB strains obtained in this study. In addition, sodium acetate was shown to improve the selectivity of this beer-based medium. Further comparative study was performed with five other media widely used for the detection of beer-spoilage LAB in the brewing industry. This study revealed that the newly developed medium, designated advanced beer-spoiler detection (ABD) medium, possessed superior sensitivity for hard-to-culture beer-spoilage LAB and comparable sensitivity with easy-to-culture beer-spoilage LAB. Moreover, ABD medium was found to suppress the growth of nonspoilage micro-organisms, and thereby allow the selective growth of beer-spoilage LAB. Advanced beer-spoiler detection medium is considered as an effective tool for comprehensive detection of beer-spoilage LAB in breweries. The detection by ABD medium can be used as an indicator for differentiating the beer-spoilage ability of LAB without further confirmatory tests in breweries.

  11. Food toxin detection with atomic force microscope

    Science.gov (United States)

    Externally introduced toxins or internal spoilage correlated pathogens and their metabolites are all potential sources of food toxins. To prevent and protect unsafe food, many food toxin detection techniques have been developed to detect various toxins for quality control. Although several routine m...

  12. Rapid species identification of seafood spoilage and pathogenic Gram-positive bacteria by MALDI-TOF mass fingerprinting.

    Science.gov (United States)

    Böhme, Karola; Fernández-No, Inmaculada C; Barros-Velázquez, Jorge; Gallardo, Jose M; Cañas, Benito; Calo-Mata, Pilar

    2011-11-01

    The rapid identification of food pathogenic and spoilage bacteria is important to ensure food quality and safety. Seafood contaminated with pathogenic bacteria is one of the major causes of food intoxications, and the rapid spoilage of seafood products results in high economic losses. In this study, a collection of the main seafood pathogenic and spoilage Gram-positive bacteria was compiled, including Bacillus spp., Listeria spp., Clostridium spp., Staphylococcus spp. and Carnobacterium spp. The strains, belonging to 20 different species, were obtained from the culture collections and studied by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). A reference library was created, including the spectral fingerprints of 32 reference strains and the extracted peak lists with 10-30 peak masses. Genus-specific as well as species-specific peak masses were assigned and could serve as biomarkers for the rapid bacterial identification. Furthermore, the peak mass lists were clustered with the web-application SPECLUST to show the phyloproteomic relationships among the studied strains. Afterwards, the method was successfully applied to identify six strains isolated from seafood by comparison with the reference library. Additionally, phylogenetic analysis based on the 16S rRNA gene was carried out and contrasted with the proteomic approach. This is the first time MALDI-TOF MS fingerprinting is applied to Gram-positive bacterial identification in seafood, being a fast and accurate technique to ensure seafood quality and safety. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Optimized dispersion of ZnO nanoparticles and antimicrobial activity against foodborne pathogens and spoilage microorganisms

    Energy Technology Data Exchange (ETDEWEB)

    Perez Espitia, Paula Judith; Ferreira Soares, Nilda de Fatima, E-mail: nfsoares1@gmail.com [Department of Food Technology, Federal University of Vicosa (Brazil); Teofilo, Reinaldo F. [Federal University of Vicosa, Department of Chemistry (Brazil); Vitor, Debora M.; Reis Coimbra, Jane Selia dos; Andrade, Nelio Jose de [Department of Food Technology, Federal University of Vicosa (Brazil); Sousa, Frederico B. de; Sinisterra, Ruben D. [Federal University of Minas Gerais, Department of Chemistry (Brazil); Medeiros, Eber Antonio Alves [Department of Food Technology, Federal University of Vicosa (Brazil)

    2013-01-15

    Single primary nanoparticles of zinc oxide (nanoZnO) tend to form particle collectives, resulting in loss of antimicrobial activity. This work studied the effects of probe sonication conditions: power, time, and the presence of a dispersing agent (Na{sub 4}P{sub 2}O{sub 7}), on the size of nanoZnO particles. NanoZnO dispersion was optimized by response surface methodology (RSM) and characterized by the zeta potential (ZP) technique. NanoZnO antimicrobial activity was investigated at different concentrations (1, 5, and 10 % w/w) against four foodborne pathogens and four spoilage microorganisms. The presence of the dispersing agent had a significant effect on the size of dispersed nanoZnO. Minimum size after sonication was 238 nm. An optimal dispersion condition was achieved at 200 W for 45 min of sonication in the presence of the dispersing agent. ZP analysis indicated that the ZnO nanoparticle surface charge was altered by the addition of the dispersing agent and changes in pH. At tested concentrations and optimal dispersion, nanoZnO had no antimicrobial activity against Pseudomonas aeruginosa, Lactobacillus plantarum, and Listeria monocytogenes. However, it did have antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Staphylococcus aureus, Saccharomyces cerevisiae, and Aspergillus niger. Based on the exhibited antimicrobial activity of optimized nanoZnO against some foodborne pathogens and spoilage microorganisms, nanoZnO is a promising antimicrobial for food preservation with potential application for incorporation in polymers intended as food-contact surfaces.

  14. A new cause of spoilage in goose sausages.

    Science.gov (United States)

    Iacumin, Lucilla; Manzano, Marisa; Panseri, Sara; Chiesa, Luca; Comi, Giuseppe

    2016-09-01

    The aim of this work was to determine the microorganisms present and to investigate their metabolites that cause spoilage of many goose sausages produced in Friuli, a northeast region of Italy. The defect was observed by sensorial analysis using the "needle probing" technique; the spoiled sausages were unsafe and not marketable. Despite the addition of starter, the microorganisms, particularly enterococci and Enterobacteriaceae, grew during ripening and produced a large amount of biogenic amines; therefore, these sausages represented a risk to consumers. The production of those compounds was confirmed in vitro. Furthermore, a second cause of spoilage was attributed to moulds that grew during ripening; the fungi grew between the meat and casing, producing a large amount of total volatile nitrogen, and consequently an ammonia smell was present either in the ripening area or in the sausages. This is the first description of this type of defect in goose sausages. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Multi spectral imaging analysis for meat spoilage discrimination

    DEFF Research Database (Denmark)

    Christiansen, Asger Nyman; Carstensen, Jens Michael; Papadopoulou, Olga

    In the present study, fresh beef fillets were purchased from a local butcher shop and stored aerobically and in modified atmosphere packaging (MAP, CO2 40%/O2 30%/N2 30%) at six different temperatures (0, 4, 8, 12, 16 and 20°C). Microbiological analysis in terms of total viable counts (TVC...... microbiological and (bio)chemical methods are employed to assess meat spoilage, the majority of which are slow, time-consuming and expensive procedures and thus, it would be most preferable to be replaced by faster and directly applicable methods. Therefore developing a procedure by associating image data...... with corresponding sensory data would be of great interest. The purpose of this research was to produce a method capable of quantifying and/or predicting the spoilage status (e.g. express in TVC counts as well as on sensory evaluation) using a multi spectral image of a meat sample and thereby avoid any time-consuming...

  16. Identification of beer spoilage microorganisms using the MALDI Biotyper platform.

    Science.gov (United States)

    Turvey, Michelle Elizabeth; Weiland, Florian; Meneses, Jon; Sterenberg, Nick; Hoffmann, Peter

    2016-03-01

    Beer spoilage microorganisms present a major risk for the brewing industry and can lead to cost-intensive recall of contaminated products and damage to brand reputation. The applicability of molecular profiling using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in combination with Biotyper software was investigated for the identification of beer spoilage microorganisms from routine brewery quality control samples. Reference mass spectrum profiles for three of the most common bacterial beer spoilage microorganisms (Lactobacillus lindneri, Lactobacillus brevis and Pediococcus damnosus), four commercially available brewing yeast strains (top- and bottom-fermenting) and Dekkera/Brettanomyces bruxellensis wild yeast were established, incorporated into the Biotyper reference library and validated by successful identification after inoculation into beer. Each bacterial species could be accurately identified and distinguished from one another and from over 5600 other microorganisms present in the Biotyper database. In addition, wild yeast contaminations were rapidly detected and distinguished from top- and bottom-fermenting brewing strains. The applicability and integration of mass spectrometry profiling using the Biotyper platform into existing brewery quality assurance practices within industry were assessed by analysing routine microbiology control samples from a local brewery, where contaminating microorganisms could be reliably identified. Brewery-isolated microorganisms not present in the Biotyper database were further analysed for identification using LC-MS/MS methods. This renders the Biotyper platform a promising candidate for biological quality control testing within the brewing industry as a more rapid, high-throughput and cost-effective technology that can be tailored for the detection of brewery-specific spoilage organisms from the local environment.

  17. Bacterial populations and the volatilome associated to meat spoilage.

    Science.gov (United States)

    Casaburi, Annalisa; Piombino, Paola; Nychas, George-John; Villani, Francesco; Ercolini, Danilo

    2015-02-01

    Microbial spoilage of meat is a complex event to which many different bacterial populations can contribute depending on the temperature of storage and packaging conditions. The spoilage can derive from microbial development and consumption of meat nutrients by bacteria with a consequent release of undesired metabolites. The volatile organic compounds (VOCs) that are generated during meat storage can have an olfactory impact and can lead to rejection of the product when their concentration increase significantly as a result of microbial development. The VOCs most commonly identified in meat during storage include alcohols, aldehydes, ketones, fatty acids, esters and sulfur compounds. In this review, the VOCs found in fresh meat during storage in specific conditions are described together with the possible bacterial populations responsible of their production. In addition, on the basis of the data available in the literature, the sensory impact of the VOCs and their dynamics during storage is discussed to highlight their possible contribution to the spoilage of meat. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Antimicrobial properties of commercial annatto extracts against selected pathogenic, lactic acid, and spoilage microorganisms.

    Science.gov (United States)

    Galindo-Cuspinera, Veronica; Westhoff, Dennis C; Rankin, Scott A

    2003-06-01

    Annatto preparations are used to impart distinctive flavor and color to foods and are a primary colorant in dairy foods such as cheese and butter. There are several reports indicating that certain fractions of the annatto plant have biological activities against microorganisms of significance in food fermentation, food preservation, and human health. However, little is reported describing the nature of the antimicrobial compound(s) or their potential presence in commercial annatto colorant preparations. This study was conducted to determine whether commonly available annatto extracts are capable of influencing the outgrowth of selected lactic acid, spoilage, and pathogenic microorganisms. Disk diffusion and tube macrodilution techniques were used to determine the MICs and MBCs of double-strength water-soluble annatto extracts. Standard antibiotic disks were used as controls for the disk diffusion assay. The results demonstrate that annatto has an inhibitory effect on Bacillus cereus, Clostridium perfringens, and Staphylococcus aureus, with MICs of 0.08, 0.31, and 0.16% (vol/vol) and diameters of inhibition of 9 to 10, 12 to 13, and 15 to 16 mm, respectively. A concentration of 0.63% (vol/vol) inhibited the growth of Streptococcus thermophilus, Lactobacillus casei subsp. casei, Lactococcus lactis, and Paenibacillus polymyxa. The MICs for Listeria monocytogenes and Enterococcus durans were 1.25 and 2.5% (vol/vol), respectively. No activity was detected against Lactobacillus plantarum, Bifidobacterium bifidum, yeasts, or selected gram-negative bacteria.

  19. Binary combination of epsilon-poly-L-lysine and isoeugenol affect progression of spoilage microbiota in fresh turkey meat, and delay onset of spoilage in Pseudomonas putida challenged meat.

    Science.gov (United States)

    Hyldgaard, Morten; Meyer, Rikke L; Peng, Min; Hibberd, Ashley A; Fischer, Jana; Sigmundsson, Arnar; Mygind, Tina

    2015-12-23

    Proliferation of microbial population on fresh poultry meat over time elicits spoilage when reaching unacceptable levels, during which process slime production, microorganism colony formation, negative organoleptic impact and meat structure change are observed. Spoilage organisms in raw meat, especially Gram-negative bacteria can be difficult to combat due to their cell wall composition. In this study, the natural antimicrobial agents ε-poly-L-lysine (ε-PL) and isoeugenol were tested individually and in combinations for their activities against a selection of Gram-negative strains in vitro. All combinations resulted in additive interactions between ε-PL and isoeugenol towards the bacteria tested. The killing efficiency of different ratios of the two antimicrobial agents was further evaluated in vitro against Pseudomonas putida. Subsequently, the most efficient ratio was applied to a raw turkey meat model system which was incubated for 96 h at spoilage temperature. Half of the samples were challenged with P. putida, and the bacterial load and microbial community composition was followed over time. CFU counts revealed that the antimicrobial blend was able to lower the amount of viable Pseudomonas spp. by one log compared to untreated samples of challenged turkey meat, while the single compounds had no effect on the population. However, the compounds had no effect on Pseudomonas spp. CFU in unchallenged meat. Next-generation sequencing offered culture-independent insight into population diversity and changes in microbial composition of the meat during spoilage and in response to antimicrobial treatment. Spoilage of unchallenged turkey meat resulted in decreasing species diversity over time, regardless of whether the samples received antimicrobial treatment. The microbiota composition of untreated unchallenged meat progressed from a Pseudomonas spp. to a Pseudomonas spp., Photobacterium spp., and Brochothrix thermosphacta dominated food matrix on the expense of low

  20. Guide to the Salvage of Temperature-Abused Food Products in Military Commissaries

    Science.gov (United States)

    1988-04-01

    increases in temperature of certain foods would allow the growth of bacterial pathogens andjor the production of toxins. This proposed procedure...products and conditions that result in least food spoilage upon refrigeration time-temperature interruption and SAFE-4 for highest chance of spoilage . See...TECHNICAL REPORT NAVICK/TR-88/050 A /% iatoA GUIDE TO THE SALVAGE OF TEMPERATURE-ABUSED FOOD PRODUCTS IN MILITARY COMMISSARIES BY R.V

  1. The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.

    Science.gov (United States)

    Rodrigues, Fernando; Sousa, Maria João; Ludovico, Paula; Santos, Helena; Côrte-Real, Manuela; Leão, Cecília

    2012-01-01

    Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13)C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13)C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2), C(3) and C(4). The incorporation of [U-(14)C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

  2. Physiological characterization of spoilage strains of Zygosaccharomyces bailii and Zygosaccharomyces rouxii isolated from high sugar environments.

    Science.gov (United States)

    Martorell, Patricia; Stratford, Malcolm; Steels, Hazel; Fernández-Espinar, Ma Teresa; Querol, Amparo

    2007-03-10

    Two isolates of spoilage yeasts Zygosaccharomyces bailii and Zygosaccharomyces rouxii were obtained from a high sugar environment, in a factory producing candied fruit and nougat. Other strains, Z. bailii from other environments and other isolates from high sugar/salt environments were obtained for comparison (Zygosaccharomyces lentus, Candida magnoliae, Candida halophila and Pichia guilliermondii). A full physiological assessment of these isolates was carried out, of preservative and biocide resistance, osmotolerance, ethanol-tolerance, low pH resistance, degree of fermentation, and growth temperature and survival to pasteurisation. Results showed that the strains isolated from high sugar environments did not show extreme physiology. These were robust strains but within the normal parameters expected for the species. One exception to this was that the Z. bailii strains were abnormally able to grow at 37 degrees C. In all strains other than C. magnolia and C. halophila, cells were able to adapt to high levels of sugar. Cultures grown in high glucose concentrations were subsequently able to tolerate higher concentrations of glucose than previously. Similarly, high sugar was found to confer a degree of protection against pasteurisation, enabling survival in what would have otherwise been a lethal treatment. Isolates of Z. bailii showed a high level of resistance to preservatives such as sorbic acid, benzoic acid, acetic acid, cinnamic acid, and ethanol, and also to heat. Unexpectedly Z. bailii isolates were not exceptionally resistant to biocides such as peracetic acid, or hypochlorite. These results indicate that spoilage by yeasts such as Z. bailii may be better prevented by use of biocidal cleaning agents in the factory, rather than treating the food with preservatives.

  3. Survival of Spoilage and Pathogenic Microorganisms on Cardboard and Plastic Packaging Materials

    Directory of Open Access Journals (Sweden)

    Lorenzo Siroli

    2017-12-01

    Full Text Available The aim of this work was to study the interaction of corrugated and plastic materials with pathogenic and spoiling microorganisms frequently associated to fresh produce. The effect of the two packaging materials on the survival during the storage of microorganisms belonging to the species Escherichia coli, Listeria monocytogenes, Salmonella enteritidis, Saccharomyces cerevisiae, Lactobacillus plantarum, Pseudomonas fluorescens, and Aspergillus flavus was studied through traditional plate counting and scanning electron microscopy (SEM. The results obtained showed that cardboard materials, if correctly stored, reduced the potential of packaging to cross-contaminate food due to a faster viability loss by spoilage and pathogenic microorganisms compared to the plastic ones. In fact, the cell loads of the pathogenic species considered decreased over time independently on the inoculation level and packaging material used. However, the superficial viability losses were significantly faster in cardboard compared to plastic materials. The same behavior was observed for the spoilage microorganisms considered. The SEM microphotographs indicate that the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this material. In addition, SEM data showed that the entrapped cells were subjected to more or less rapid lyses, depending on the species, due to the absence of water and nutrients, with the exception of molds. The latter spoilers were able to proliferate inside the cardboard fibers only when the absorption of water was not prevented during the storage. In conclusion, the findings of this work showed the reduction of cross-contamination potential of corrugated compared to plastic packaging materials used in fruit and vegetable sector. However, the findings outlined the importance of hygiene and low humidity during cardboard storage to prevent the mold growth on

  4. Control of Native Spoilage Yeast on Dealcoholized Red Wine by Preservatives Alone and in Binary Mixtures.

    Science.gov (United States)

    Sánchez-Rubio, Marta; Guerrouj, Kamal; Taboada-Rodríguez, Amaury; López-Gómez, Antonio; Marín-Iniesta, Fulgencio

    2017-09-01

    In order to preserve a commercial dealcoholized red wine (DRW), a study with 4 preservatives and binary mixtures of them were performed against 2 native spoilage yeasts: Rhodotorula mucilaginosa and Saccharomyces cerevisiae. Minimal inhibitory concentration (MIC) and minimal fungicidal concentration (MFC) for potassium sorbate, sodium benzoate, sodium metabisulfite and dimethyl dicarbonate (DMDC) were evaluated in DRW stored at 25 °C. MICs of potassium sorbate and sodium metabisulfite were 250 and 60 mg/kg, respectively for both target strains. However for sodium benzoate, differences between yeasts were found; R. mucilaginosa was inhibited at 125 mg/kg, while S. cerevisiae at 250 mg/kg. Regarding MFC, differences between strains were only found for sodium metabisulfite obtaining a MFC of 500 mg/kg for R. mucilaginosa and a MFC of 250 mg/kg for S. cerevisiae. Potassium sorbate and sodium benzoate showed the MFC at 1000 mg/kg and DMDC at 200 mg/kg. Regarding the effect of binary mixtures the Fractional Fungicidal Concentration Index (FFC i ) methodology showed that binary mixtures of 100 mg/kg DMDC/200 mg/kg potassium sorbate (FFC i = 0.7) and 50 mg/kg DMDC / 400 mg/kg sodium benzoate (FFC i = 0.65) have both synergistic effect against the 2 target strains. These binary mixtures can control the growth of spoilage yeasts in DRW without metabisulfite addition. The results of this work may be important in preserving the health of DRW consumers by eliminating the use of metabisulfite and reducing the risk of growth of R. mucilagosa, recently recognized as an emerging pathogen. © 2017 Institute of Food Technologists®.

  5. Survival of Spoilage and Pathogenic Microorganisms on Cardboard and Plastic Packaging Materials.

    Science.gov (United States)

    Siroli, Lorenzo; Patrignani, Francesca; Serrazanetti, Diana I; Chiavari, Cristiana; Benevelli, Marzia; Grazia, Luigi; Lanciotti, Rosalba

    2017-01-01

    The aim of this work was to study the interaction of corrugated and plastic materials with pathogenic and spoiling microorganisms frequently associated to fresh produce. The effect of the two packaging materials on the survival during the storage of microorganisms belonging to the species Escherichia coli , Listeria monocytogenes , Salmonella enteritidis , Saccharomyces cerevisiae , Lactobacillus plantarum , Pseudomonas fluorescens , and Aspergillus flavus was studied through traditional plate counting and scanning electron microscopy (SEM). The results obtained showed that cardboard materials, if correctly stored, reduced the potential of packaging to cross-contaminate food due to a faster viability loss by spoilage and pathogenic microorganisms compared to the plastic ones. In fact, the cell loads of the pathogenic species considered decreased over time independently on the inoculation level and packaging material used. However, the superficial viability losses were significantly faster in cardboard compared to plastic materials. The same behavior was observed for the spoilage microorganisms considered. The SEM microphotographs indicate that the reduction of superficial contamination on cardboard surfaces was due to the entrapping of the microbial cells within the fibers and the pores of this material. In addition, SEM data showed that the entrapped cells were subjected to more or less rapid lyses, depending on the species, due to the absence of water and nutrients, with the exception of molds. The latter spoilers were able to proliferate inside the cardboard fibers only when the absorption of water was not prevented during the storage. In conclusion, the findings of this work showed the reduction of cross-contamination potential of corrugated compared to plastic packaging materials used in fruit and vegetable sector. However, the findings outlined the importance of hygiene and low humidity during cardboard storage to prevent the mold growth on packaging.

  6. Pulsed-light inactivation of pathogenic and spoilage bacteria on cheese surface.

    Science.gov (United States)

    Proulx, J; Hsu, L C; Miller, B M; Sullivan, G; Paradis, K; Moraru, C I

    2015-09-01

    Cheese products are susceptible to postprocessing cross-contamination by bacterial surface contamination during slicing, handling, or packaging, which can lead to food safety issues and significant losses due to spoilage. This study examined the effectiveness of pulsed-light (PL) treatment on the inactivation of the spoilage microorganism Pseudomonas fluorescens, the nonenterohemorrhagic Escherichia coli ATCC 25922 (nonpathogenic surrogate of Escherichia coli O157:H7), and Listeria innocua (nonpathogenic surrogate of Listeria monocytogenes) on cheese surface. The effects of inoculum level and cheese surface topography and the presence of clear polyethylene packaging were evaluated in a full factorial experimental design. The challenge microorganisms were grown to early stationary phase and subsequently diluted to reach initial inoculum levels of either 5 or 7 log cfu/slice. White Cheddar and process cheeses were cut into 2.5×5 cm slices, which were spot-inoculated with 100 µL of bacterial suspension. Inoculated cheese samples were exposed to PL doses of 1.02 to 12.29 J/cm(2). Recovered survivors were enumerated by standard plate counting or the most probable number technique, as appropriate. The PL treatments were performed in triplicate and data were analyzed using a general linear model. Listeria innocua was the least sensitive to PL treatment, with a maximum inactivation level of 3.37±0.2 log, followed by P. fluorescens, with a maximum inactivation of 3.74±0.8 log. Escherichia coli was the most sensitive to PL, with a maximum reduction of 5.41±0.1 log. All PL inactivation curves were nonlinear, and inactivation reached a plateau after 3 pulses (3.07 J/cm(2)). The PL treatments through UV-transparent packaging and without packaging consistently resulted in similar inactivation levels. This study demonstrates that PL has strong potential for decontamination of the cheese surface. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc

  7. The fate of acetic acid during glucose co-metabolism by the spoilage yeast Zygosaccharomyces bailii.

    Directory of Open Access Journals (Sweden)

    Fernando Rodrigues

    Full Text Available Zygosaccharomyces bailii is one of the most widely represented spoilage yeast species, being able to metabolise acetic acid in the presence of glucose. To clarify whether simultaneous utilisation of the two substrates affects growth efficiency, we examined growth in single- and mixed-substrate cultures with glucose and acetic acid. Our findings indicate that the biomass yield in the first phase of growth is the result of the weighted sum of the respective biomass yields on single-substrate medium, supporting the conclusion that biomass yield on each substrate is not affected by the presence of the other at pH 3.0 and 5.0, at least for the substrate concentrations examined. In vivo(13C-NMR spectroscopy studies showed that the gluconeogenic pathway is not operational and that [2-(13C]acetate is metabolised via the Krebs cycle leading to the production of glutamate labelled on C(2, C(3 and C(4. The incorporation of [U-(14C]acetate in the cellular constituents resulted mainly in the labelling of the protein and lipid pools 51.5% and 31.5%, respectively. Overall, our data establish that glucose is metabolised primarily through the glycolytic pathway, and acetic acid is used as an additional source of acetyl-CoA both for lipid synthesis and the Krebs cycle. This study provides useful clues for the design of new strategies aimed at overcoming yeast spoilage in acidic, sugar-containing food environments. Moreover, the elucidation of the molecular basis underlying the resistance phenotype of Z. bailii to acetic acid will have a potential impact on the improvement of the performance of S. cerevisiae industrial strains often exposed to acetic acid stress conditions, such as in wine and bioethanol production.

  8. Mechanism of Action of Electrospun Chitosan-Based Nanofibers against Meat Spoilage and Pathogenic Bacteria.

    Science.gov (United States)

    Arkoun, Mounia; Daigle, France; Heuzey, Marie-Claude; Ajji, Abdellah

    2017-04-06

    This study investigates the antibacterial mechanism of action of electrospun chitosan-based nanofibers (CNFs), against Escherichia coli , Salmonella enterica serovar Typhimurium, Staphylococcus aureus and Listeria innocua , bacteria frequently involved in food contamination and spoilage. CNFs were prepared by electrospinning of chitosan and poly(ethylene oxide) (PEO) blends. The in vitro antibacterial activity of CNFs was evaluated and the susceptibility/resistance of the selected bacteria toward CNFs was examined. Strain susceptibility was evaluated in terms of bacterial type, cell surface hydrophobicity, and charge density, as well as pathogenicity. The efficiency of CNFs on the preservation and shelf life extension of fresh red meat was also assessed. Our results demonstrate that the antibacterial action of CNFs depends on the protonation of their amino groups, regardless of bacterial type and their mechanism of action was bactericidal rather than bacteriostatic. Results also indicate that bacterial susceptibility was not Gram-dependent but strain-dependent, with non-virulent bacteria showing higher susceptibility at a reduction rate of 99.9%. The susceptibility order was: E. coli > L. innocua > S. aureus > S. Typhimurium. Finally, an extension of one week of the shelf life of fresh meat was successfully achieved. These results are promising and of great utility for the potential use of CNFs as bioactive food packaging materials in the food industry, and more specifically in meat quality preservation.

  9. Antimicrobial activity of essential oils from Mediterranean aromatic plants against several foodborne and spoilage bacteria.

    Science.gov (United States)

    Silva, Nuno; Alves, Sofia; Gonçalves, Alexandre; Amaral, Joana S; Poeta, Patrícia

    2013-12-01

    The antimicrobial activity of essential oils extracted from a variety of aromatic plants, often used in the Portuguese gastronomy was studied in vitro by the agar diffusion method. The essential oils of thyme, oregano, rosemary, verbena, basil, peppermint, pennyroyal and mint were tested against Gram-positive (Listeria monocytogenes, Clostridium perfringens, Bacillus cereus, Staphylococcus aureus, Enterococcus faecium, Enterococcus faecalis, and Staphylococcus epidermidis) and Gram-negative strains (Salmonella enterica, Escherichia coli, and Pseudomonas aeruginosa). For most essential oils examined, S. aureus, was the most susceptible bacteria, while P. aeruginosa showed, in general, least susceptibility. Among the eight essential oils evaluated, thyme, oregano and pennyroyal oils showed the greatest antimicrobial activity, followed by rosemary, peppermint and verbena, while basil and mint showed the weakest antimicrobial activity. Most of the essential oils considered in this study exhibited a significant inhibitory effect. Thyme oil showed a promising inhibitory activity even at low concentration, thus revealing its potential as a natural preservative in food products against several causal agents of foodborne diseases and food spoilage. In general, the results demonstrate that, besides flavoring the food, the use of aromatic herbs in gastronomy can also contribute to a bacteriostatic effect against pathogens.

  10. Facts about food irradiation: Status and trends

    International Nuclear Information System (INIS)

    1991-01-01

    This fact sheet introduces the concept of irradiating food to reduce post-harvest losses from infestation, contamination and spoilage, to lower the incidence of foodborne diseases and to assist international trade in food products by offering an alternative to fumigation or some other treatments that may not be acceptable to the importing countries

  11. Basics of radiation microbiology for food protection

    International Nuclear Information System (INIS)

    Wills, P.A.

    1985-01-01

    The microbiological basics of food poisoning, food spoilage, and ionizing energy treatments are presented. Factors influencing the microbial resistance of ionizing radiation, including the use of physical agents for combination treatments, are briefly reviewed, and parameters involved in dose selection are considered

  12. Current strategies for improving food bacteria

    NARCIS (Netherlands)

    Kuipers, O P; Buist, Girbe; Kok, Jan

    2000-01-01

    Novel concepts and methodologies are emerging that hold great promise for the directed improvement of food-related bacteria, specifically lactic acid bacteria. Also, the battle against food spoilage and pathogenic bacteria can now be fought more effectively. Here we describe recent advances in

  13. Characteristics of Spoilage-Associated Secondary Cucumber Fermentation

    Science.gov (United States)

    Franco, Wendy; Johanningsmeier, Suzanne D.; McFeeters, Roger F.

    2012-01-01

    Secondary fermentations during the bulk storage of fermented cucumbers can result in spoilage that causes a total loss of the fermented product, at an estimated cost of $6,000 to $15,000 per affected tank. Previous research has suggested that such fermentations are the result of microbiological utilization of lactic acid and the formation of acetic, butyric, and propionic acids. The objectives of this study were to characterize the chemical and environmental conditions associated with secondary cucumber fermentations and to isolate and characterize potential causative microorganisms. Both commercial spoilage samples and laboratory-reproduced secondary fermentations were evaluated. Potential causative agents were isolated based on morphological characteristics. Two yeasts, Pichia manshurica and Issatchenkia occidentalis, were identified and detected most commonly concomitantly with lactic acid utilization. In the presence of oxygen, yeast metabolic activities lead to lactic acid degradation, a small decline in the redox potential (Eh, Ag/AgCl, 3 M KCl) of the fermentation brines, and an increase in pH to levels at which bacteria other than the lactic acid bacteria responsible for the primary fermentation can grow and produce acetic, butyric, and propionic acids. Inhibition of these yeasts by allyl isothiocyanate (AITC) resulted in stabilization of the fermented medium, while the absence of the preservative resulted in the disappearance of lactic and acetic acids in a model system. Additionally, three Gram-positive bacteria, Lactobacillus buchneri, a Clostridium sp., and Pediococcus ethanolidurans, were identified as potentially relevant to different stages of the secondary fermentation. The unique opportunity to study commercial spoilage samples generated a better understanding of the microbiota and environmental conditions associated with secondary cucumber fermentations. PMID:22179234

  14. Lactobacillus oligofermentans sp. nov., Associated with Spoilage of Modified-Atmosphere-Packaged Poultry Products

    Science.gov (United States)

    Koort, Joanna; Murros, Anna; Coenye, Tom; Eerola, Susanna; Vandamme, Peter; Sukura, Antti; Björkroth, Johanna

    2005-01-01

    Unidentified lactic acid bacterium (LAB) isolates which had mainly been detected in spoiled, marinated, modified atmosphere packaged (MAP) broiler meat products during two previous studies, were identified and analyzed for their phenotypic properties and the capability to produce biogenic amines. To establish the taxonomic position of these isolates, 16S rRNA gene sequence analysis, numerical analysis of ribopatterns, and DNA-DNA hybridization experiments were done. Unexpectedly for a meat-spoilage-associated LAB, the strains utilized glucose very weakly. According to the API 50 CHL test, arabinose and xylose were the only carbohydrates strongly fermented. None of the six strains tested for production of histamine, tyramine, tryptamine, phenylethylamine, putrescine, and cadaverine were able to produce these main meat-associated biogenic amines in vitro. The polyphasic taxonomy approach showed that these strains represent a new Lactobacillus species. The six isolates sequenced for the 16S rRNA encoding genes shared the highest similarity (95.0 to 96.3%) with the sequence of the Lactobacillus durianis type strain. In the phylogenetic tree, these isolates formed a distinct cluster within the Lactobacillus reuteri group, which also includes L. durianis. Numerical analyses of HindIII-EcoRI ribotypes placed all isolates together in a cluster with seven subclusters well separated from the L. reuteri group reference strains. The DNA-DNA hybridization levels between Lactobacillus sp. nov. isolates varied from 67 to 96%, and low hybridization levels (3 to 15%) were obtained with the L. durianis type strain confirming that these isolates belong to the same species different from L. durianis. The name Lactobacillus oligofermentans sp. nov. is proposed, with strain LMG 22743T (also known as DSM 15707T or AMKR18T) as the type strain. PMID:16085830

  15. Prediction of spoilage of tropical shrimp (Penaeus notialis) under dynamic temperature regimes

    NARCIS (Netherlands)

    Dabade, D.S.; Azokpota, P.; Nout, M.J.R.; Hounhouigan, D.J.; Zwietering, M.H.; Besten, den H.M.W.

    2015-01-01

    The spoilage activity of Pseudomonas psychrophila and Carnobacterium maltaromaticum, two tropical shrimp (Penaeus notialis) spoilage organisms, was assessed in cooked shrimps stored at 0 to 28 °C. Microbiological, chemical and sensory analyses were performed during storage. P. psychrophila had a

  16. Spoilage potential and sensory profile associated with bacteria isolated from cold-smoked salmon

    OpenAIRE

    Stohr, Valerie; Joffraud, Jean-jacques; Cardinal, Mireille; Leroi, Francoise

    2001-01-01

    Off-odours/flavours associated with cold-smoked salmon spoilage are due to the activity of microflora. This study evaluated the spoilage potential of nine bacterial groups (Shewanella putrefaciens, Brochothrix thermosphacta, Aeromonas spp., Lactobacillus alimentarius, Lactobacillus sake,Lactobacillus farciminis, Carnobacterium piscicola, Photobacterium phosphoreum and Serratia liquefaciens) isolated from cold-smoked salmon. Five different isolates from each group were inoculated into sterile ...

  17. Metabolic footprinting of Lactobacillus buchneri strain LA1147 during anaerobic spoilage of fermented cucumbers

    Science.gov (United States)

    Lactobacillus buchneri has recently been associated with anaerobic spoilage of fermented cucumbers due to its ability to metabolize lactic acid into acetic acid and 1,2-propanediol. However, we have limited knowledge of other chemical components in fermented cucumber that may be related to spoilage ...

  18. Spoilage evaluation, shelf-life prediction, and potential spoilage organisms of tropical brackish water shrimp (Penaeus notialis) at different storage temperatures

    NARCIS (Netherlands)

    Dabade, D.S.; Besten, den H.M.W.; Azokpota, P.; Nout, M.J.R.; Hounhouigan, D.J.; Zwietering, M.H.

    2015-01-01

    Maintaining the freshness of shrimp is a concern to shrimp stakeholders. To improve shrimp quality management, it is of importance to evaluate shrimp spoilage characteristics. Therefore, microbiological, sensory, and chemical changes of naturally contaminated tropical brackish water shrimp (Penaeus

  19. Spoilage fungi and their mycotoxins in commercially marketed chestnuts

    DEFF Research Database (Denmark)

    Overy, David Patrick; Seifert, K.A.; Savard, M.E.

    2003-01-01

    A nationwide survey was carried out to assess mould spoilage of Castanea sativa nuts sold in Canadian grocery stores in 1998-99. Morphological and cultural characters, along with secondary metabolite profiles derived from thin-layer chromatography, were used to sort and identify fungi cultured from...... isolated, but at a much lower frequency. HPLC and diode array detection were used to confirm the suspected presence of the mycotoxins penitrem A, chactoglobosin A and C, emodin and ochratoxin A in extracts prepared from naturally infected nut tissue. To the best of our knowledge, this is the first time...

  20. Volatile components associated with bacterial spoilage of tropical prawns

    DEFF Research Database (Denmark)

    Chinivasagam, H.N.; Bremner, Allan; Wood, A.F.

    1998-01-01

    Analysis of headspace volatiles by gas chromatography/mass spectrometry from king (Penaeus plebejus), banana (P. merguiensis), tiger (P. esculentus/semisulcatus) and greasy (Metapenaeus bennettae) prawns stored in ice or ice slurry, which is effectively an environment of low oxygen tension......, whereas sulphides and amines occurred whether the predominant spoilage organism was Ps.fragi or Shewanella putrefaciens. The free amino acid profiles of banana and king prawns were high in arginine (12-14%) and low in cysteine (0.1-0.17%) and methionine (0.1-0.2%). Filter sterilised raw banana prawn broth...

  1. Identification and Quantification of Volatile Chemical Spoilage Indexes Associated with Bacterial Growth Dynamics in Aerobically Stored Chicken.

    Science.gov (United States)

    Mikš-Krajnik, Marta; Yoon, Yong-Jin; Ukuku, Dike O; Yuk, Hyun-Gyun

    2016-08-01

    Volatile organic compounds (VOCs) as chemical spoilage indexes (CSIs) of raw chicken breast stored aerobically at 4, 10, and 21 °C were identified and quantified using solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS). The growth dynamics of total viable count (TVC), psychrotrophs, Pseudomonas spp., lactic acid bacteria (LAB), Brochothrix thermosphacta and H2 S producing bacteria were characterized based on maximum growth rates (μmax ), maximal microbial concentration (Nmax ) and at the moment of microbial shelf life (Svalues ), calculated from Gompertz-fitted growth curves. Pseudomonas spp. was predominant species, while B. thermosphacta was characterized by the highest μmax . The microbiological and sensory shelf lives were estimated based on TVC, Pseudomonas spp., and B. thermosphacta counts and sensory evaluation, respectively. Among 27 VOCs identified by GC-MS in spoiled chicken samples, ethanol (EtOH), 1-butanol-3-methyl (1But-3M), and acetic acid (C2 ) achieved the highest Pearson's correlation coefficients of 0.66, 0.61, and 0.59, respectively, with TVC, regardless of storage temperature. Partial least squares (PLS) regression revealed that the synthesis of 1But-3M and C2 was most likely induced by the metabolic activity of B. thermosphacta and LAB, while EtOH was attributed to Pseudomonas spp. The increase in concentration of selected volatile spoilage markers (EtOH, 1But-3M, and C2 ) in the headspace over spoiled chicken breast was found to be statistically significant (P growth. These findings highlight the possibility of analyzing the combination of 3 selected spoilage markers: EtOH, 1But-3M, and C2 as rapid evaluation for poultry quality testing using SPME-GC-MS. © 2016 Institute of Food Technologists®

  2. Radiation microbiology in food preservation

    International Nuclear Information System (INIS)

    Wills, P.A.

    1983-01-01

    The lethal effect of ionizing energy on micro-organisms and the influence of species, growth phase, gaseous atmosphere, temperature, water activity, chemical sensitizers and physical agents on microbial resistance are described briefly. Concern has often been expressed that the use of low doses of ionizing energy for processing food might result in mutants with increased resistance, virulence or toxin production capacity, that diagnostic characteristics of pathogens may alter, or that alterations in normal food spoilage patterns could cause storage problems. These fears are examined in a food preservation context and found to be unwarranted. The rationale for quantitative estimates of the dose of ionizing energy needed for specific food preservation applications is given and comparison made between the ionizing energy sensitivities of food pathogens and spoilage organisms

  3. Effect of Equilibrated pH and Indigenous Spoilage Microorganisms on the Inhibition of Proteolytic Clostridium botulinum Toxin Production in Experimental Meals under Temperature Abuse.

    Science.gov (United States)

    Golden, Max C; Wanless, Brandon J; David, Jairus R D; Lineback, D Scott; Talley, Ryan J; Kottapalli, Bala; Glass, Kathleen A

    2017-08-01

    Clostridium botulinum is a foreseeable biological hazard in prepared refrigerated meals that needs to be addressed in food safety plans. The objective of this study was to evaluate the effect of product composition and storage temperature on the inhibition of botulinum toxin formation in nine experimental meals (meat, vegetable, or carbohydrate based). Treatments were inoculated with proteolytic C. botulinum, vacuum packaged, cooked at 90°C for 10 min, and assayed for botulinum toxin in samples stored at 25°C for up to 96 h for phase 1, or at 25°C for 12 h and then transferred to 12.5°C for up to 12 and 6 weeks in phases 1 and 2, respectively. For phase 1, none of the treatments (equilibrated pH 5.8) supported toxin production when stored at 25°C for 48 h, but toxin production was observed in all treatments at 72 h. For the remaining experiments with storage at 12.5°C, toxin production was dependent on equilibrated pH, storage time, and growth of indigenous spoilage microorganisms. In phase 1, no gross spoilage and no botulinum toxin was detected for any treatment (pH ≤5.8) stored at 12.5°C for 12 weeks. In phase 2, gross spoilage varied by commodity, with the brussels sprouts meal with pH 6.5 showing the most rapid spoilage within 2 weeks and botulinum toxin detected at 5 and 6 weeks for the control and cultured celery juice treatments, respectively. In contrast, spoilage microbes decreased the pH of a pH 5.9 beef treatment by 1.0 unit, potentially inhibiting C. botulinum through 6 weeks at 12.5°C. None of the other treatments with pH 5.8 or below supported toxin production or spoilage. This study provides validation for preventive controls in refrigerated meals. These include equilibrated product pH and storage temperature and time to inhibit toxin formation by proteolytic C. botulinum, but the impact of indigenous microflora on safety and interpretation of challenge studies is also highlighted.

  4. Food irradiation and sterilization

    International Nuclear Information System (INIS)

    Josephson, E.S.

    1981-01-01

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25 to 70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning in achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70 to 80 0 C (bacon to 53 0 C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurrence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40 0 C to -20 0 C). Radappertized foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for 'wholesomeness' (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effects of radappertization on the 'wholesomeness' characteristics of these foods. (author)

  5. Food irradiation and sterilization

    Science.gov (United States)

    Josephson, Edward S.

    Radiation sterilization of food (radappertization) requires exposing food in sealed containers to ionizing radiation at absorbed doses high enough (25-70 kGy) to kill all organisms of food spoilage and public health significance. Radappertization is analogous to thermal canning is achieving shelf stability (long term storage without refrigeration). Except for dry products in which autolysis is negligible, the radappertization process also requires that the food be heated to an internal temperature of 70-80°C (bacon to 53°C) to inactivate autolytic enzymes which catalyze spoilage during storage without refrigeration. To minimize the occurence of irradiation induced off-flavors and odors, undesirable color changes, and textural and nutritional losses from exposure to the high doses required for radappertization, the foods are vacuum sealed and irradiated frozen (-40°C to -20°C). Radappertozed foods have the characteristic of fresh foods prepared for eating. Radappertization can substitute in whole or in part for some chemical food additives such as ethylene oxide and nitrites which are either toxic, carcinogenic, mutagenic, or teratogenic. After 27 years of testing for "wholesomeness" (safety for consumption) of radappertized foods, no confirmed evidence has been obtained of any adverse effecys of radappertization on the "wholesomeness" characteristics of these foods.

  6. Coexistence of Lactic Acid Bacteria and Potential Spoilage Microbiota in a Dairy Processing Environment.

    Science.gov (United States)

    Stellato, Giuseppina; De Filippis, Francesca; La Storia, Antonietta; Ercolini, Danilo

    2015-11-01

    Microbial contamination in food processing plants can play a fundamental role in food quality and safety. In this study, the microbiota in a dairy plant was studied by both 16S rRNA- and 26S rRNA-based culture-independent high-throughput amplicon sequencing. Environmental samples from surfaces and tools were studied along with the different types of cheese produced in the same plant. The microbiota of environmental swabs was very complex, including more than 200 operational taxonomic units with extremely variable relative abundances (0.01 to 99%) depending on the species and sample. A core microbiota shared by 70% of the samples indicated a coexistence of lactic acid bacteria with a remarkable level of Streptococcus thermophilus and possible spoilage-associated bacteria, including Pseudomonas, Acinetobacter, and Psychrobacter, with a relative abundance above 50%. The most abundant yeasts were Kluyveromyces marxianus, Yamadazyma triangularis, Trichosporon faecale, and Debaryomyces hansenii. Beta-diversity analyses showed a clear separation of environmental and cheese samples based on both yeast and bacterial community structure. In addition, predicted metagenomes also indicated differential distribution of metabolic pathways between the two categories of samples. Cooccurrence and coexclusion pattern analyses indicated that the occurrence of potential spoilers was excluded by lactic acid bacteria. In addition, their persistence in the environment can be helpful to counter the development of potential spoilers that may contaminate the cheeses, with possible negative effects on their microbiological quality. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  7. Effects of aqueous extract of Cinnamomum verum on growth of bread spoilage fungi

    Directory of Open Access Journals (Sweden)

    Monir Doudi

    2016-01-01

    Full Text Available Food waste has been identified as a considerable problem and bread is the most wasted food. This study aimed to evaluate In-vitro anti-fungal activity of cinnamon extract on bread spoilage fungi and to determine its anti-fungal effect in the bread slices. At first, the MIC and MFC values of the extract were determined against Aspergillus niger, Aspergillus flavus, Aspergillus fumigatus, Penicillium chrysogenum, Penicillium notatum and Rhizopus oryzae. Then, Aspergillus sp was selected to assess antifungal activities of different doses of cinnamon extract in bread slices. Cinnamon extract at a dose of 64 mg/ml completely inhibited all standard and bread isolated fungi. This concentration of extract also inhibited Aspergillus growth on bread slices and delayed colony formation but adversely affected the sensory characteristics of bread. Cinnamon extract at 32 mg/ml not only delayed fungal growth, but also improved bread shelf life and delayed its staling. Moreover, 32mg/ml of extract did not adversely affect bread aroma, flavor and texture. However, sodium acetate inhibited the growth of Aspergillus sp but is not recommended for fungal control because it is considered as chemical. Therefore 32 mg/ml of extract is recommended for increasing the shelf-life of flat bread.

  8. Food preservation by irradiation

    International Nuclear Information System (INIS)

    Kooij, J. van

    1981-01-01

    Twenty-five years of development work on the preservation of food by irradiation have shown that this technology has the potential to reduce post-harvest losses and to produce safe foods. The technological feasibility has been established but general acceptance of food irradiation by national regulatory bodies and consumers requires attention. The positive aspects of food preservation by irradiation include: the food keeps its freshness and its physical state, agents which cause spoilage (bacteria, etc.) are eliminated, recontamination does not take place, provided packaging materials are impermeable to bacteria and insects. It inhibits sprouting of root crops, kills insects and parasites, inactivates bacteria, spores and moulds, delays ripening of fruit, improves the technological properties of food. It makes foods biologically safe, allows the production of shelf-stable foods and is excellent for quarantine treatment, and generally improves food hygiene. The dose ranges needed for effective treatment are given

  9. Evaluation of natural antimicrobials on typical meat spoilage bacteria in vitro and in vacuum-packed pork meat.

    Science.gov (United States)

    Schirmer, Bjørn Christian; Langsrud, Solveig

    2010-03-01

    The aim of this study was to investigate the inhibitory effect of natural antimicrobials on the growth of typical spoilage bacteria from marinated pork. Minimum inhibitory concentrations (MIC) of thymol, cinnamaldehyde, allyl isothiocyanate, citric acid, ascorbic acid, a rosemary extract, and a grapefruit seed extract against Lactobacillus algidus, Leuconostoc mesenteroides, Leuconostoc carnosum, Carnobacterium maltaromaticum, Carnobacterium divergens, Brochothrix thermosphacta, and Serratia proteamaculans were determined in a microplate assay. Combinations of antimicrobials were tested and several combinations showed synergistic effects in inhibiting bacterial growth. Single and combined antimicrobials were added to vacuum-packed pork meat to evaluate preserving effects. Antimicrobial concentrations of up to 10 times the MIC values showed no effect on total bacterial growth in vacuum packed pork meaning that although most antimicrobials inhibited the growth of spoilage bacteria in vitro, results from the microplate assay could not be transferred to the meat system. Most natural antimicrobials possess strong odor and flavor that limit their use as a food preservative. In conclusion, this study showed that the use of natural antimicrobials in meat products is limited and that bacterial quality and shelf life was not enhanced under the chosen conditions.

  10. Species-Level Discrimination of Psychrotrophic Pathogenic and Spoilage Gram-Negative Raw Milk Isolates Using a Combined MALDI-TOF MS Proteomics-Bioinformatics-based Approach.

    Science.gov (United States)

    Vithanage, Nuwan R; Bhongir, Jeevana; Jadhav, Snehal R; Ranadheera, Chaminda S; Palombo, Enzo A; Yeager, Thomas R; Datta, Nivedita

    2017-06-02

    Identification of psychrotrophic pathogenic and spoilage Gram-negative bacteria using rapid and reliable techniques is important in commercial milk processing, as these bacteria can produce heat-resistant proteases and act as postprocessing contaminants in pasteurized milk. Matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) is a proven technology for identification of bacteria in food, however, may require optimization for identification of pathogenic and spoilage bacteria in milk and dairy products. The current study evaluated the effects of various culture conditions and sample preparation methods on assigning of raw milk isolates to the species level by MALDI-TOF MS. The results indicated that culture media, incubation conditions (temperature and time), and sample preparation significantly affected the identification rates of bacteria to the species level. Nevertheless, the development of spectral libraries of isolates grown on different media using a web tool for hierarchical clustering of peptide mass spectra (SPECLUST) followed by a ribosomal protein based bioinformatics approach significantly enhanced the assigning of bacteria, with at least one unique candidate biomarker peak identified for each species. Phyloproteomic relationships based on spectral profiles were compared to phylogenetic analysis using 16S rRNA gene sequences and demonstrated similar clustering patterns with significant discriminatory power. Thus, with appropriate optimization, MALDI-TOF MS is a valuable tool for species-level discrimination of pathogenic and milk spoilage bacteria.

  11. Food irradiation : an alternative technology for an emerging need

    International Nuclear Information System (INIS)

    Yang, Jae Seung

    1998-01-01

    Development and implementation of food irradiation was driven by needs pertaining to food safety improvement, food spoilage reduction, and quarantine/trade. The need for food safety is caused by the increasing morbidity and mortality caused by food-borne diseases worldwide, and it affects national economy and world-trade. Radiation technology can serve to ameliorate the vulnerability of our food supply system. (author)

  12. Food irradiation

    International Nuclear Information System (INIS)

    1991-01-01

    Processing of food with low levels of radiation has the potential to contribute to reducing both spoilage of food during storage - a particular problem in developing countries - and the high incidence of food-borne disease currently seen in all countries. Approval has been granted for the treatment of more than 30 products with radiation in over 30 countries but, in general, governments have been slow to authorize the use of this new technique. One reason for this slowness is a lack of understanding of what food irradiation entails. This book aims to increase understanding by providing information on the process of food irradiation in simple, non-technical language. It describes the effects that irradiation has on food, and the plant and equipment that are necessary to carry it out safely. The legislation and control mechanisms required to ensure the safety of food irradiation facilities are also discussed. Education is seen as the key to gaining the confidence of the consumers in the safety of irradiated food, and to promoting understanding of the benefits that irradiation can provide. (orig.) With 4 figs., 1 tab [de

  13. Food irradiation

    International Nuclear Information System (INIS)

    Migdal, W.

    1995-01-01

    A worldwide standard on food irradiation was adopted in 1983 by codex Alimentarius Commission of the Joint Food Standard Programme of the Food and Agriculture Organization (FAO) of the United Nations and The World Health Organization (WHO). As a result, 41 countries have approved the use of irradiation for treating one or more food items and the number is increasing. Generally, irradiation is used to: food loses, food spoilage, disinfestation, safety and hygiene. The number of countries which use irradiation for processing food for commercial purposes has been increasing steadily from 19 in 1987 to 33 today. In the frames of the national programme on the application of irradiation for food preservation and hygienization an experimental plant for electron beam processing has been established in Inst. of Nuclear Chemistry and Technology. The plant is equipped with a small research accelerator Pilot (19 MeV, 1 kW) and industrial unit Electronika (10 MeV, 10 kW). On the basis of the research there were performed at different scientific institutions in Poland, health authorities have issued permissions for irradiation for; spices, garlic, onions, mushrooms, potatoes, dry mushrooms and vegetables. (author)

  14. [Food additives and healthiness].

    Science.gov (United States)

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  15. Lactococcus lactis - a diploid bacterium

    DEFF Research Database (Denmark)

    Michelsen, Ole; Hansen, Flemming G.; Jensen, Peter Ruhdal

    the next division. Thus, the regions of the chromosome that are the last to be replicated are haploid even in fast-growing bacteria. In contrast to this general rule for bacteria, we found that Lactococcus lactis, a bacterium which has been exploited for thousands of years for the production of fermented...... milk products, is born with two complete non-replicating chromosomes. L. lactis therefore remain diploid throughout its entire life cycle....

  16. Advances in the control of wine spoilage by Zygosaccharomyces and Dekkera/Brettanomyces.

    Science.gov (United States)

    Zuehlke, J M; Petrova, B; Edwards, C G

    2013-01-01

    Understanding the characteristics of yeast spoilage, as well as the available control technologies, is vital to producing consistent, high-quality wine. Zygosaccharomyces bailii contamination may result in refermentation and CO2 production in sweet wines or grape juice concentrate, whereas Brettanomyces bruxellensis spoilage often contributes off-odors and flavors to red wines. Early detection of these yeasts by selective/differential media or genetic methods is important to minimize potential spoilage. More established methods of microbial control include sulfur dioxide, dimethyl dicarbonate, and filtration. Current research is focused on the use of chitosan, pulsed electric fields, low electric current, and ultrasonics as means to protect wine quality.

  17. Foods

    Science.gov (United States)

    Brennan, Charles

    2012-11-21

    There is one commodity the world over that unites mankind-food. In 2011 the United Nations claimed that the world's population had reached the seven billion mark, a number which is set to increase dramatically in the decades to come. Food security, supply and sustainability are of paramount concern to the future economic and social progress of humanity. It is the responsibility of the food industry, together with food scientists and technologists, to shoulder the burden of ensuring an adequate supply of nutritious, safe and sensorially acceptable foods for a range of demanding consumers. In responding to this challenge, we need to understand the link between agriculture, engineering, food processing, molecular biosciences, human nutrition, commercialisation and innovation. Access to information concerning the composition and quality of foods has never been so easy for consumers and technologists alike. A plethora of research publications are made available each month to scientists and associated interested parties. The outcomes of these research manuscripts are often distilled and disseminated into messages available to everyone through bulletin boards, forums and the popular press. Newspapers and new agencies constantly report on the latest pharma-medical finding, or news regarding food safety and security concerns. We live in an age where information is so readily available to everyone that the task of finding credible and reputable data can be difficult at times. Providing sound evidenced based research is where a peer-reviewed journal can provide clarity. [...].

  18. Development of Volatile Oil of Mustard and Vanillin as an Effective Food Preservation System for Military Bread and Baked Goods

    National Research Council Canada - National Science Library

    Muller, Wayne S; Sikes, Anthony; Yeomans, Walter; Anderson, Danielle; Senecal, Andy

    2006-01-01

    ...) vanillin is an effective food preservation system for molds and yeast. Four bread spoilage organisms were evaluated in the study Penicillium notatum, Rhizopus stolonifer, Aspergillus niger, and Saccharomycopsis fibuligera...

  19. Bacillus subtilis Biosensor Engineered To Assess Meat Spoilage

    NARCIS (Netherlands)

    Daszczuk, Alicja; Dessalegne, Yonathan; Drenth, Ismael; Hendriks, Elbrich; Jo, Emeraldo; van Lente, Tom; Oldebesten, Arjan; Parrish, Jonathon; Poljakova, Wlada; Purwanto, Annisa A.; van Raaphorst, Renske; Boonstra, Mirjam; van Heel, Auke; Herber, Martijn; van der Meulen, Sjoerd; Siebring, Jeroen; Sorg, Robin A.; Heinemann, Matthias; Kuipers, Oscar P.; Veening, Jan-Willem

    2014-01-01

    Here, we developed a cell-based biosensor that can assess meat freshness using the Gram-positive model bacterium Bacillus subtilis as a chassis. Using transcriptome analysis, we identified promoters that are specifically activated by volatiles released from spoiled meat. The most strongly activated

  20. Incorporation of nisin in natural casing for the control of spoilage microorganisms in vacuum packaged sausage.

    Science.gov (United States)

    de Barros, Joyce Regina; Kunigk, Leo; Jurkiewicz, Cynthia Hyppolito

    2010-10-01

    This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1) 0.1% food grade phosphoric acid; 2) 5.0 mg/L nisin; 3) 0.1% phosphoric acid and 5.0 mg/L nisin; and 4) sterile water (control). The sausages were produced in a pilot plant, stuffed into the pretreated natural casings, vacuum packaged and stored at 4 and 10 °C for 56 days. The experiments were performed according to a full factorial design 2(3), totalizing 8 treatments that were repeated in 3 blocks. Aerobic plate counts and lactic acid bacteria analysis were conducted at 1, 14, 28, 42 and 56 days of storage. Treatment of casings with phosphoric acid 0.1% alone did not inhibit the growth of lactic acid bacteria and reduced the aerobic plate count by 1 log. The activity of nisin against lactic acid bacteria was enhanced by the addition of phosphoric acid, demonstrating a synergistic effect. Furthermore nisin activity was more evident at lower storage temperature (4 ºC). Therefore treatment of the natural casings with nisin and phosphoric acid, combined with low storage temperature, are obstacles that present a potential for controlling the growth of lactic acid bacteria in vacuum packaged sausage.

  1. Incorporation of nisin in natural casing for the control of spoilage microorganisms in vacuum packaged sausage

    Directory of Open Access Journals (Sweden)

    Joyce Regina de Barros

    2010-12-01

    Full Text Available This study aimed to evaluate the effectiveness of natural casing treatment with nisin and phosphoric acid on control of spoilage microorganisms in vacuum packaged sausages. Ovine casings were dipped in the following baths: 1 0.1% food grade phosphoric acid; 2 5.0 mg/L nisin; 3 0.1% phosphoric acid and 5.0 mg/L nisin; and 4 sterile water (control. The sausages were produced in a pilot plant, stuffed into the pretreated natural casings, vacuum packaged and stored at 4 and 10 °C for 56 days. The experiments were performed according to a full factorial design 2³, totalizing 8 treatments that were repeated in 3 blocks. Aerobic plate counts and lactic acid bacteria analysis were conducted at 1, 14, 28, 42 and 56 days of storage. Treatment of casings with phosphoric acid 0.1% alone did not inhibit the growth of lactic acid bacteria and reduced the aerobic plate count by 1 log. The activity of nisin against lactic acid bacteria was enhanced by the addition of phosphoric acid, demonstrating a synergistic effect. Furthermore nisin activity was more evident at lower storage temperature (4 ºC. Therefore treatment of the natural casings with nisin and phosphoric acid, combined with low storage temperature, are obstacles that present a potential for controlling the growth of lactic acid bacteria in vacuum packaged sausage.

  2. Essential Oils Against Pathogen and Spoilage Microorganisms of Fruit Juices: Use of Versatile Antimicrobial Delivery Systems.

    Science.gov (United States)

    Trinetta, Valentina; Morgan, Mark T; Coupland, John N; Yucel, Umut

    2017-02-01

    Essential oils (EO) are increasingly used as natural antimicrobial compounds, however the effect of delivery system to enhance their antimicrobial activity has not been widely studied. Limonene (0 to 10 μL/mL) was added to microbial suspensions (∼10 5 CFU/mL) of selected foodborne pathogens (Listeria monocytogenes Scott A, Salmonella enterica Typhimurium, Escherichia coli and Staphylococcus aureus), and spoilage microorganisms (Lactobacillus plantarum, Saccharomyces cerevisiae, and Candida albicans). S. aureus was found to be the most sensitive foodborne pathogen while Salmonella enterica showed continued growth under all concentrations. Stable nanoemulsions and solid lipid nanoparticles (SLN) (d ∼ 170 nm) were prepared using an alkane carrier oil (n-tetradecane and n-eicosane, respectively). Interfacial effects and homogenous distribution of limonene in nanoemulsions improved its (8 and 12 μL/mL) antimicrobial effect against S. aureus. Higher aqueous concentrations as a result of expulsion from SLN further enhanced the antimicrobial activity pronounced at higher limonene concentrations. Therefore, our findings confirm that the emulsion-based delivery systems are able to effectively distribute limonene inside a microbial suspension to improve its antimicrobial activity. © 2017 Institute of Food Technologists®.

  3. Involvement of Bacterial Quorum-Sensing Signals in Spoilage of Bean Sprouts

    OpenAIRE

    Rasch, Maria; Andersen, Jens Bo; Nielsen, Kristian Fog; Flodgaard, Lars Ravn; Christensen, Henrik; Givskov, Michael; Gram, Lone

    2005-01-01

    Bacterial communication signals, acylated homoserine lactones (AHLs), were extracted from samples of commercial bean sprouts undergoing soft-rot spoilage. Bean sprouts produced in the laboratory did not undergo soft-rot spoilage and did not contain AHLs or AHL-producing bacteria, although the bacterial population reached levels similar to those in the commercial sprouts, 108 to 109 CFU/g. AHL-producing bacteria (Enterobacteriaceae and pseudomonads) were isolated from commercial sprouts, and s...

  4. Exploring lot-to-lot variation in spoilage bacterial communities on commercial modified atmosphere packaged beef.

    Science.gov (United States)

    Säde, Elina; Penttinen, Katri; Björkroth, Johanna; Hultman, Jenni

    2017-04-01

    Understanding the factors influencing meat bacterial communities is important as these communities are largely responsible for meat spoilage. The composition and structure of a bacterial community on a high-O 2 modified-atmosphere packaged beef product were examined after packaging, on the use-by date and two days after, to determine whether the communities at each stage were similar to those in samples taken from different production lots. Furthermore, we examined whether the taxa associated with product spoilage were distributed across production lots. Results from 16S rRNA amplicon sequencing showed that while the early samples harbored distinct bacterial communities, after 8-12 days storage at 6 °C the communities were similar to those in samples from different lots, comprising mainly of common meat spoilage bacteria Carnobacterium spp., Brochothrix spp., Leuconostoc spp. and Lactococcus spp. Interestingly, abundant operational taxonomic units associated with product spoilage were shared between the production lots, suggesting that the bacteria enable to spoil the product were constant contaminants in the production chain. A characteristic succession pattern and the distribution of common spoilage bacteria between lots suggest that both the packaging type and the initial community structure influenced the development of the spoilage bacterial community. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Papain Immobilized Polyurethane Film as Antimicrobial Food Package

    OpenAIRE

    M. Cynthya; V. Prabhawathi; D. Mukesh

    2014-01-01

    Food contamination occurs during post process handling. This leads to spoilage and growth of pathogenic microorganisms in the food, thereby reducing its shelf life or spreading of food borne diseases. Several methods are tried and one of which is use of antimicrobial packaging. Here, papain, a protease enzyme, is covalently immobilized with the help of glutarldehyde on polyurethane and used as a food wrap to protect food from microbial contamination. Covalent immobilizati...

  6. Detection of food treated with ionizing radiation

    International Nuclear Information System (INIS)

    Delincee, H.

    1998-01-01

    Treatment of food with ionizing energy-'food irradiation'- is finally becoming reality in many countries. The benefits include an improvement in food hygiene, spoilage reduction and extension of shelf-life. Although properly irradiated food is safe and wholesome, consumers should be able to make their own free choice between irradiated and non-irradiated food. For this purpose labelling is indispensable. In order to check compliance with existing regulations, detection of radiation treatment by analysing the food itself is highly desirable. Significant progress has been made in recent years in developing analytical detection methods utilizing changes in food originating from the radiation treatment

  7. Fate and control of pathogenic and spoilage micro-organisms in orange blossom (Citrus aurantium) and rose flower (Rosa centifolia) hydrosols.

    Science.gov (United States)

    Labadie, C; Cerutti, C; Carlin, F

    2016-12-01

    Hydrosols are hydrodistillation products used in food and cosmetic industries, perfumery, pharmacy and aromatherapy. The ability of preservatives to control previously reported bacterial proliferation and spoilage was evaluated. All tested preservatives were authorized for food and cosmetic application. Major pathogens of concern for foods and cosmetics were poorly able to grow in rose and orange blossom hydrosols when inoculated and incubated at 30°C. Commercial antimicrobials, such as isothiazolinone, chlorphenesin and paraben solutions, benzyl alcohol and sodium benzoate at pH = 5·0, controlled the growth of Pseudomonas and Burkholderia sp. strains representative of the natural microbiota of both hydrosols for >90 days at 30°C, only at concentrations close to the authorized limits. Concentrations of some of the tested preservatives that controlled growth at 5°C were lower than at 30°C. Pathogenic micro-organisms likely represent a low risk in rose flower and orange blossom hydrosol. However, the oligotrophic character of hydrosols and the antimicrobial properties of their essential oils do not prevent microbiological spoilage by the naturally present microbiota. In the absence of aseptic conditions and microbial inactivation process, only preservatives can stabilize hydrosols for a several-month storage. Several effective preservatives have been identified. © 2016 The Society for Applied Microbiology.

  8. Characterization of the radioresistance in the radioresistant bacterium deinococcus radiodurans

    International Nuclear Information System (INIS)

    Kong Xiangrong; Du Zeji

    1999-01-01

    The radioresistance of wild type Deinococcus radiodurans KD8301 and the factors affecting the radioresistance were investigated. KH3111 which was a DNA repair mutant of KD8301 (Zeji Du, 1998) was used to be compared with KD8301. Deinococcus radiodurans was discovered by Anderson et al (1956) in X-ray sterilized canned meat that was found to have undergone spoilage. this bacterium and other species of this genus share extreme resistance to ionizing radiation and other agents that damage DNA. Wild type KD8301 and its sensitive mutant KH3111 were irradiated with 60 Co γ-ray at the dose range 0.5 ∼ 10 kGy. Dose-survival fraction curves were made and the radio resistances were determined by LD 99 . The relative contents of DNA in cells were measured by Fluorescence Spectrophotometry (Freedman and Bruce, 1971). The results indicated that wild type KD8301 possesses more radioresistant than its mutant KH3111, LD99 were 9.5 kGy and 2.4 kGy respectively. KD8301 grown at exponential phase showed a decreased resistance to radiation, and the LD99 was 5.1 kGy. No differences of DNA/protein in cells were found between the exponential phase and the stationary phase. The results could be concluded that wild type KD8301 possesses remarkable radioresistance, but this ability was decreased or disappeared after mutation (in KH3111). None DNA relative content other than the growth stages were determinant factors of radioresistance in Deinococcus radiodurans. This results were different from other report (Dickie N et al, 1990). The cellular mechanisms might be the deference's of the bacterium cell morphology between the exponential phase and the stationary phase. Recently, the mutation site of KH3111 which was mutated chemically from wild type KD8301 was identified (Zeji Du, 1998). One base pair changed in the novel gene pprA which was isolated from KD8301 genomic DNA. This point mutation was confirmed to be responsible for the sensitivity of KH3111 to γ-ray and other DNA

  9. Contamination of salmon fillets and processing plants with spoilage bacteria.

    Science.gov (United States)

    Møretrø, Trond; Moen, Birgitte; Heir, Even; Hansen, Anlaug Å; Langsrud, Solveig

    2016-11-21

    The processing environment of salmon processing plants represents a potential major source of bacteria causing spoilage of fresh salmon. In this study, we have identified major contamination routes of important spoilage associated species within the genera Pseudomonas, Shewanella and Photobacterium in pre-rigor processing of salmon. Bacterial counts and culture-independent 16S rRNA gene analysis on salmon fillet from seven processing plants showed higher levels of Pseudomonas spp. and Shewanella spp. in industrially processed fillets compared to salmon processed under strict hygienic conditions. Higher levels of Pseudomonas spp. and Shewanella spp. were found on fillets produced early on the production day compared to later processed fillets. The levels of Photobacterium spp. were not dependent on the processing method or time of processing. In follow-up studies of two plants, bacterial isolates (n=2101) from the in-plant processing environments (sanitized equipment/machines and seawater) and from salmon collected at different sites in the production were identified by partial 16S rRNA gene sequencing. Pseudomonas spp. dominated in equipment/machines after sanitation with 72 and 91% of samples from the two plants being Pseudomonas-positive. The phylogenetic analyses, based on partial 16S rRNA gene sequencing, showed 48 unique sequence profiles of Pseudomonas of which two were dominant. Only six profiles were found on both machines and in fillets in both plants. Shewanella spp. were found on machines after sanitation in the slaughter department while Photobacterium spp. were not detected after sanitation in any parts of the plants. Shewanella spp. and Photobacterium spp. were found on salmon in the slaughter departments. Shewanella was frequently present in seawater tanks used for bleeding/short term storage. In conclusion, this study provides new knowledge on the processing environment as a source of contamination of salmon fillets with Pseudomonas spp. and

  10. Spoilage potential of Pseudomonas species isolated from goat milk.

    Science.gov (United States)

    Scatamburlo, T M; Yamazi, A K; Cavicchioli, V Q; Pieri, F A; Nero, L A

    2015-02-01

    Pseudomonas spp. are usually associated with spoilage microflora of dairy products due to their proteolytic potential. This is of particular concern for protein-based products, such as goat milk cheeses and fermented milks. Therefore, the goal of the present study was to characterize the proteolytic activity of Pseudomonas spp. isolated from goat milk. Goat milk samples (n=61) were obtained directly from bulk tanks on dairy goat farms (n=12), and subjected to a modified International Organization for Standardization (ISO) protocol to determine the number and proteolytic activity of Pseudomonas spp. Isolates (n=82) were obtained, identified by PCR, and subjected to pulsed-field gel electrophoresis with XbaI macro-restriction. Then, the isolates were subjected to PCR to detect the alkaline protease gene (apr), and phenotypic tests were performed to check proteolytic activity at 7°C, 25°C, and 35°C. Mean Pseudomonas spp. counts ranged from 2.9 to 4.8 log cfu/mL, and proteolytic Pseudomonas spp. counts ranged from 1.9 to 4.6 log cfu/mL. All isolates were confirmed to be Pseudomonas spp., and 41 were identified as Pseudomonas fluorescens, which clustered into 5 groups sharing approximately 82% similarity. Thirty-six isolates (46.9%) were positive for the apr gene; and 57 (69.5%) isolates presented proteolytic activity at 7°C, 82 (100%) at 25°C, and 64 (78%) at 35°C. The isolates were distributed ubiquitously in the goat farms, and no relationship among isolates was observed when the goat farms, presence of apr, pulsotypes, and proteolytic activity were taken into account. We demonstrated proteolytic activity of Pseudomonas spp. present in goat milk by phenotypic and genotypic tests and indicated their spoilage potential at distinct temperatures. Based on these findings and the ubiquity of Pseudomonas spp. in goat farm environments, proper monitoring and control of Pseudomonas spp. during production are critical. Copyright © 2015 American Dairy Science Association

  11. Food irradiation now

    International Nuclear Information System (INIS)

    1982-01-01

    From the start the Netherlands has made an important contribution to the irradiation of food through microbiological and toxicological research as well as through the setting-up of a pilot plant by the government and through the practical application of 'Gammaster' on a commercial basis. The proceedings of this tenth anniversary symposium of 'Gammaster' present all aspects of food irradiation and will undoubtedly help to remove the many misunderstandings. They offer information and indicate to the potential user a method that can make an important contribution to the prevention of decay and spoilage of foodstuffs and to the exclusion of food-borne infections and food poisoning in man. The book includes 8 contributions and 4 panel discussions in the field of microbiology; technology; legal aspects; and consumer aspects of food irradiation. As an appendix, the report 'Wholesomeness of irradiated food' of a joint FAO/IAEA/WHO Expert Committee has been added. (orig./G.J.P.)

  12. Monitoring of spoilage-associated microbiota on modified atmosphere packaged beef and differentiation of psychrophilic and psychrotrophic strains.

    Science.gov (United States)

    Hilgarth, M; Behr, J; Vogel, R F

    2018-03-01

    This study aimed to explore the discriminatory power of MALDI-TOF MS as a high-throughput method to monitor growth dynamics of meat-spoiling bacteria on modified atmosphere packaged (MAP) beef and to differentiate psychrophilic and psychrotrophic spoilage-associated strains. MAP beef steaks were incubated for 21 days at constant 4 and 10°C. Development of headspace gas composition, pH, CFU and spoilage-associated microbial composition were monitored. MALDI-TOF MS exhibited high discriminatory power for reliable, high-throughput identification of spoilage-associated, psychrotrophic microbiota. Microbiota development was highly dependent on initial abundance of specific species. Organoleptic onset of spoilage was concomitant with an alteration of headspace atmosphere and pH. Screening for psychrophiles at 4°C on beef revealed the abundance of Leuconostoc gelidum subsp. gelidum TMW2·1998 with characteristic psychrophilic growth behaviour. We suggest that control of initial contaminants is crucial to predict the onset of spoilage and that headspace atmosphere and pH are important parameters with spoilage-indicative potential. MALDI-TOF MS proved suitable for high-resolution monitoring of psychrotrophic and psychrophilic spoilage-associated microbiota and enables improved insights in the spoilage progress. The presence of psychrophilic strains on beef is the likely causative for unexplained spoilage events. © 2017 The Society for Applied Microbiology.

  13. High-level production of diacetyl in a metabolically engineered lactic acid bacterium

    DEFF Research Database (Denmark)

    2017-01-01

    The present invention provides a genetically modified lactic acid bacterium capable of producing diacetyl under aerobic conditions. Additionally the invention provides a method for producing diacetyl using the genetically modified lactic acid bacterium under aerobic conditions in the presence...... of a source of iron-containing porphyrin and a metal ion selected from Fe3+, Fe2+ and Cu2+. The lactic acid bacterium is genetically modified by deletion of those genes in its genome that encode polypeptides having lactate dehydrogenase (E.C 1.1.1.27/E.C.1.1.1.28); α-acetolactate decarboxylase (E.C 4.......C. 1.1.1.4/1.1.1.-) and alcohol dehydrogenase (E.C. 1.2.1.10) activity. The invention provides for use of the genetically modified lactic acid bacterium for the production of diacetyl and a food product....

  14. Recall costs balanced against spoilage control in Dutch custard.

    Science.gov (United States)

    Velthuis, A G J; Reij, M W; Baritakis, K; Dang, M; van Wagenberg, C P A

    2010-06-01

    The relation between the moment at which a recall of Dutch custard is initiated and the direct costs of this recall was investigated. A simulation model of the custard supply chain was developed to compare scenarios with and without a quarantine of 48 h at the storage of the production plant. The model consists of 3 parts: 1) the distribution of a 24,000-L batch of custard over the supply chain over time is simulated; 2) the time to detect spoilage bacteria with a recontamination test procedure is simulated; and 3) the direct recall costs of custard over the different parts of the supply chain are calculated. Direct recall costs increase from about 25,000 euros/batch to 36,171 euros/batch from 57 to 135 h in the situation without quarantine and from 25,000 euros/batch to 36,648 euros/batch from 123 h to 163 h for the situation with quarantine. Then costs decrease because more and more custard is at the consumer level and only 0.13% of the consumers will ask for a refund. With low true contamination probabilities quarantine is not profitable, but at later detection moments with high probabilities it is. We conclude that a simulation model is a helpful tool to evaluate the efficiency of risk management strategies like end product testing and a quarantine situation. 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  15. Ancient Item Spoilage Ritual Used in Nomadic Burial Rite

    Directory of Open Access Journals (Sweden)

    Beisenov Arman Z.

    2017-07-01

    Full Text Available The article considers the findings of items in ancient burials which were intentionally spoiled prior to deposition in graves. This tradition was widely spread both in terms of chronology and geography, and therefore cannot be attributed to any individual cultures or regions. The authors present new information on the ritual obtained during an investigation of Borsyk burial mound of the Middle Sarmatian period located in West Kazakhstan. The central grave of barrow 6 contained a heavily damaged bronze cauldron. The grave was looted in antiquity. Individual scattered bones of a human skeleton and minor gold foil adornments from the ceremonial dress of a nobleman were discovered in the grave. The authors suggest that the cauldron was intentionally deformed by the participants of an ancient mortuary and memorial ritual. According to the principal hypothesis concerning the essence of this ritual, spoilage of the items was related to the idea of assign the items with “different” and “transcendent” properties, which resulted from the necessity of burying the owner. Cauldrons played an important role in the life of steppe leaders. The authors assume a sacral nature of the use of cauldrons in the culture of steppe peoples associated with feasts, battles, and sacred hunting. Perhaps, there was a tradition of burying cauldrons together with their owners after spoiling the items in view of the concept of the other world and the role of a heroic leader therein.

  16. The Role of Cold-Shock Proteins in Low-Temperature Adaptation of Food-Related Bacteria

    NARCIS (Netherlands)

    Wouters, Jeroen A.; Rombouts, Frank M.; Kuipers, Oscar P.; Vos, Willem M. de; Abee, T.

    2000-01-01

    There is a considerable interest in the cold adaptation of food-related bacteria, including starter cultures for industrial food fermentations, food spoilage bacteria and food-borne pathogens. Mechanisms that permit low-temperature growth involve cellular modifications for maintaining membrane

  17. Intake assessment of the food additives nitrite (E 249 and E 250) and nitrate (E 251 and E 252)

    NARCIS (Netherlands)

    Sprong RC; Niekerk EM; Beukers MH; VVH; V&Z

    2017-01-01

    Nitrate and nitrite are authorised as preservatives in certain food products, such as salami, ham (nitrite) and cheese (nitrate). They prevent food spoilage and protect the consumer against food-borne pathogens. Next to that, nitrate and nitrite play a role in food colour retention and contribute to

  18. Molecular identification of phosphate solubilizing bacterium ...

    African Journals Online (AJOL)

    A phosphate solubilizing bacterium was isolated from the rhizosphere soil of upland rice and identified by 16S rRNA gene sequencing. The gene sequence showed 99% homology with Alcaligenes faecalis. Based on the gene sequence homology, it was identified as A. faecalis. Interaction effect of this bacterium on growth ...

  19. Development of spoilage bacterial community and volatile compounds in chilled beef under vacuum or high oxygen atmospheres.

    Science.gov (United States)

    Jääskeläinen, Elina; Hultman, Jenni; Parshintsev, Jevgeni; Riekkola, Marja-Liisa; Björkroth, Johanna

    2016-04-16

    Research into microbial community development and metabolism is essential to understand meat spoilage. Recent years have seen the emergence of powerful molecular techniques that are being used alongside conventional microbiology approaches. This enables more accurate studies on meat spoilage. The aim of this study was to investigate the influence of packaging (under vacuum and in high oxygen atmosphere) on the development of microbial communities and metabolic activities at 6 °C by using culture-dependent (cultivation, ribotyping) and culture-independent (amplicon sequencing) methods. At the beginning of shelf life, the microbial community mostly consisted of Carnobacterium and Lactobacillus. After two weeks of storage, Lactococcus and Lactobacillus were the dominant genera under vacuum and Leuconostoc in high oxygen meat packages. This indicates that oxygen favoured the genus Leuconostoc comprising only heterofermentative species and hence potential producers of undesirable compounds. Also the number of volatile compounds, such as diacetyl, 1-octen-3-ol and hexanoic acids, was higher in high oxygen packages than under vacuum packages. The beef in high oxygen atmosphere packaging was detected as spoiled in sensory evaluation over 10 days earlier than beef under vacuum packaging. Leuconostoc gelidum, Lactococcus piscium, Lactobacillus sakei and Lactobacillus algidus were the most common species of bacteria. The results obtained from identification of the isolates using ribotyping and amplicon sequencing correlated, except for L. algidus, which was detected in both types of packaging by amplicon sequencing, but only in vacuum packaged samples using the culture-based technique. This indicates that L. algidus grew, but was not cultivable in high oxygen beef using the Nordic Committee on Food Analysis standard method. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Thymus Vulgaris (Red Thyme) and Caryophyllus Aromaticus (Clove) Essential Oils to Control Spoilage Microorganisms in Pork Under Modified Atmosphere

    Science.gov (United States)

    D’Amato, Serena; Mazzarrino, Giovanni; Rossi, Chiara; Serio, Annalisa; López, Clemencia Chaves; Celano, Gaetano Vitale; Paparella, Antonello

    2016-01-01

    In recent years, it has been confirmed that essential oils (EOs) exert antimicrobial activity as they are able to inhibit cell growth and inactivate microbial cells. The application of biopreservation strategies by means of EOs opens up interesting perspectives in the food industry, including meat production. The paper aims to evaluate the effects of Thymus vulgaris (red thyme) and Caryophyllus aromaticus (cloves) EOs on the development of the spoilage population of fresh pork packaged under modified atmosphere (MAP). In particular, the research was focused on Brochothrix thermosphacta, a specific spoilage microorganism of fresh meat packed in anaerobic conditions or under MAP. Amongst seven EOs, those that showed the highest antimicrobial activity on 5 B. thermosphacta strains in vitro were: cloves [minimum inhibitory concentration (MIC) 0.6-2.5 mg/mL], savory (MIC 2.5-5.0 mg/mL), and red thyme (MIC 2.5 to 20 mg/mL). Red thyme and cloves EOs were selected for meat treatment, by increasing the dose at 20 and 40 mg/mL respectively, to take into account the matrix effect that can reduce EO availability. In spite of the minor efficacy observed in vitro, 40 mg/mL red thyme EO strongly limited the growth of B. thermosphacta in pork samples up to day 6 of storage [below 3.0 Log colony forming unit (CFU)/g, starting from 2.0 Log CFU/g at time 0], and exerted an antimicrobial effect also on the aerobic mesophilic count. Good results were obtained also with 20 mg/mL red thyme EO. The control of B. thermosphacta growth through EOs encourages research on alternative methods for extending the shelf life of fresh meat under MAP. PMID:27853710

  1. Thymus vulgaris (red thyme and Caryophyllus aromaticus (clove essential oils to control spoilage microorganisms in pork under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Serena D'Amato

    2016-08-01

    Full Text Available In recent years, it has been confirmed that essential oils (EOs exert antimicrobial activity as they are able to inhibit cell growth and inactivate microbial cells. The application of biopreservation strategies by means of EOs opens up interesting perspectives in the food industry, including meat production. The paper aims to evaluate the effects of Thymus vulgaris (red thyme and Caryophyllus aromaticus (cloves EOs on the development of the spoilage population of fresh pork packaged under modified atmosphere (MAP. In particular, the research was focused on Brochothrix thermosphacta, a specific spoilage microorganism of fresh meat packed in anaerobic conditions or under MAP. Amongst seven EOs, those that showed the highest antimicrobial activity on 5 B. thermosphacta strains in vitro were: cloves [minimum inhibitory concentration (MIC 0.6-2.5 mg/mL], savory (MIC 2.5-5.0 mg/mL, and red thyme (MIC 2.5 to 20 mg/mL. Red thyme and cloves EOs were selected for meat treatment, by increasing the dose at 20 and 40 mg/mL respectively, to take into account the matrix effect that can reduce EO availability. In spite of the minor efficacy observed in vitro, 40 mg/mL red thyme EO strongly limited the growth of B. thermosphacta in pork samples up to day 6 of storage [below 3.0 Log colony forming unit (CFU/g, starting from 2.0 Log CFU/g at time 0], and exerted an antimicrobial effect also on the aerobic mesophilic count. Good results were obtained also with 20 mg/mL red thyme EO. The control of B. thermosphacta growth through EOs encourages research on alternative methods for extending the shelf life of fresh meat under MAP.

  2. Antibacterial activity of guava (Psidium guajava L.) and Neem (Azadirachta indica A. Juss.) extracts against foodborne pathogens and spoilage bacteria.

    Science.gov (United States)

    Mahfuzul Hoque, M D; Bari, M L; Inatsu, Y; Juneja, Vijay K; Kawamoto, S

    2007-01-01

    The antibacterial activity of guava (Psidium guajava) and neem (Azadirachta indica) extracts against 21 strains of foodborne pathogens were determined--Listeria monocytogenes (five strains), Staphylococcus aureus (four strains), Escherichia coli O157:H7 (six strains), Salmonella Enteritidis (four strains), Vibrio parahaemolyticus, and Bacillus cereus, and five food spoilage bacteria: Pseudomonas aeroginosa, P. putida, Alcaligenes faecalis, and Aeromonas hydrophila (two strains). Guava and neem extracts showed higher antimicrobial activity against Gram-positive bacteria compared to Gram-negative bacteria except for V. parahaemolyticus, P. aeroginosa, and A. hydrophila. None of the extracts showed antimicrobial activity against E. coli O157:H7 and Salmonella Enteritidis. The minimum inhibitory concentration (MIC) of ethanol extracts of guava showed the highest inhibition for L. monocytogenes JCM 7676 (0.1 mg/mL), S. aureus JCM 2151 (0.1 mg/mL), S. aureus JCM 2179 (0.1 mg/mL), and V. parahaemolyticus IFO 12711 (0.1 mg/mL) and the lowest inhibition for Alcaligenes faecalis IFO 12669, Aeromonas hydrophila NFRI 8282 (4.0 mg/mL), and A. hydrophila NFRI 8283 (4.0 mg/mL). The MIC of chloroform extracts of neem showed similar inhibition for L. monocytogenes ATCC 43256 (4.0 mg/mL) and L. monocytogenes ATCC 49594 (5.0 mg/mL). However, ethanol extracts of neem showed higher inhibition for S. aureus JCM 2151 (4.5 mg/mL) and S. aureus IFO 13276 (4.5 mg/mL) and the lower inhibition for other microorganisms (6.5 mg/mL). No significant effects of temperature and pH were found on guava and neem extracts against cocktails of L. monocytogenes and S. aureus. The results of the present study suggest that guava and neem extracts possess compounds containing antibacterial properties that can potentially be useful to control foodborne pathogens and spoilage organisms.

  3. Longterm storage of post-packaged bread by controlling spoilage pathogens using Lactobacillus fermentum C14 isolated from homemade curd.

    Science.gov (United States)

    Barman, Soma; Ghosh, Ranjan; Sengupta, Shreya; Mandal, Narayan C

    2017-01-01

    One potent lactic acid bacterial strain C14 with strong antifungal activity was isolated from homemade curd. Based on morphological as well as biochemical characters and 16S rDNA sequence homology the strain was identified as Lactobacillus fermentum. It displayed a wide antimicrobial spectrum against both Gram-positive and Gram-negative pathogenic bacteria, and also against number of food spoilage, plant and human pathogenic fungi. The cell free supernatant (CFS) of the strain C14 was also effective against the fungi tested. Inhibition of radial growth of Penicillium digitatum, Trichophyton rubrum and Mucor sp. was noticed in the presence of CFS of C14 even at low concentration (1%). More than 94.3 ± 1.6% and 91.5 ± 2.2% inhibition of conidial germination of P. digitatum and Mucor sp. were noticed in the presence of 10-fold-concentrated CFS of C14. Massive deformation of the fungal mycelia was observed by SEM studies, and losses of cellular proteins and DNA are also evident upon its treatment with C14. HPLC analysis revealed the presence of phenyl lactic acid, lactic acid along with some unidentified compounds in the antifungal extract. Challenge experiment showed immense potential of the strain C14 in preventing the spoilage of bread samples caused by Mucor sp. and Bacillus subtilis. The bread samples remained fresh upto 25 days even after inoculation with Mucor sp. (3.7 × 104 spores /ml) and B. subtilis (4.6 × 104 CFU /ml). Along with the antifungal properties, the isolated lactic acid bacterial strain also showed very good antioxidant activities. Unchanged level of liver enzymes serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase in albino mice upon feeding with C14 also suggested non-toxic nature of the bacterial isolate.

  4. Longterm storage of post-packaged bread by controlling spoilage pathogens using Lactobacillus fermentum C14 isolated from homemade curd.

    Directory of Open Access Journals (Sweden)

    Soma Barman

    Full Text Available One potent lactic acid bacterial strain C14 with strong antifungal activity was isolated from homemade curd. Based on morphological as well as biochemical characters and 16S rDNA sequence homology the strain was identified as Lactobacillus fermentum. It displayed a wide antimicrobial spectrum against both Gram-positive and Gram-negative pathogenic bacteria, and also against number of food spoilage, plant and human pathogenic fungi. The cell free supernatant (CFS of the strain C14 was also effective against the fungi tested. Inhibition of radial growth of Penicillium digitatum, Trichophyton rubrum and Mucor sp. was noticed in the presence of CFS of C14 even at low concentration (1%. More than 94.3 ± 1.6% and 91.5 ± 2.2% inhibition of conidial germination of P. digitatum and Mucor sp. were noticed in the presence of 10-fold-concentrated CFS of C14. Massive deformation of the fungal mycelia was observed by SEM studies, and losses of cellular proteins and DNA are also evident upon its treatment with C14. HPLC analysis revealed the presence of phenyl lactic acid, lactic acid along with some unidentified compounds in the antifungal extract. Challenge experiment showed immense potential of the strain C14 in preventing the spoilage of bread samples caused by Mucor sp. and Bacillus subtilis. The bread samples remained fresh upto 25 days even after inoculation with Mucor sp. (3.7 × 104 spores /ml and B. subtilis (4.6 × 104 CFU /ml. Along with the antifungal properties, the isolated lactic acid bacterial strain also showed very good antioxidant activities. Unchanged level of liver enzymes serum glutamic pyruvic transaminase and serum glutamic oxaloacetic transaminase in albino mice upon feeding with C14 also suggested non-toxic nature of the bacterial isolate.

  5. Use of a Titrimetric Method to Assess the Bacterial Spoilage of Fresh Beef 1

    Science.gov (United States)

    Shelef, Leora A.; Jay, James M.

    1970-01-01

    A new method of determining bacterial spoilage in fresh beef is presented. The technique is based upon the fact that as beef undergoes refrigerator spoilage, there is a gradual increase in the production of alkaline substances by the spoilage flora. The level of these substances was measured by titrating meat homogenates to a pH 5.00 end point, employing 0.02 n HCl and an autotitrator. When 23 samples of ground beef from retail stores were tested, an average of 1.32 ml of acid was required for titration of 1 g of fresh beef to pH 5.00, whereas 2.58 ml was required for the same meat at the onset of spoilage. Preliminary data indicate that beef which requires more than 2 ml of 0.02 n HCl/g to lower its pH to 5.00 under the conditions of the test is in some state of incipient spoilage. The statistical correlation between titration values, log bacterial numbers, and extract-release volume was high (P < 0.001). The technique is simple to execute and is highly reproducible, and duplicate samples can be run within 15 min. PMID:4917189

  6. Efficacy of lactoferricin B in controlling ready-to-eat vegetable spoilage caused by Pseudomonas spp.

    Science.gov (United States)

    Federico, Baruzzi; Pinto, Loris; Quintieri, Laura; Carito, Antonia; Calabrese, Nicola; Caputo, Leonardo

    2015-12-23

    The microbial content of plant tissues has been reported to cause the spoilage of ca. 30% of chlorine-disinfected fresh vegetables during cold storage. The aim of this work was to evaluate the efficacy of antimicrobial peptides in controlling microbial vegetable spoilage under cold storage conditions. A total of 48 bacterial isolates were collected from ready-to-eat (RTE) vegetables and identified as belonging to Acinetobacter calcoaceticus, Aeromonas media, Pseudomonas cichorii, Pseudomonas fluorescens, Pseudomonas jessenii, Pseudomonas koreensis, Pseudomonas putida, Pseudomonas simiae and Pseudomonas viridiflava species. Reddish or brownish pigmentation was found when Pseudomonas strains were inoculated in wounds on leaves of Iceberg and Trocadero lettuce and escarole chicory throughout cold storage. Bovine lactoferrin (BLF) and its hydrolysates (LFHs) produced by pepsin, papain and rennin, were assayed in vitro against four Pseudomonas spp. strains selected for their heavy spoiling ability. As the pepsin-LFH showed the strongest antimicrobial effect, subsequent experiments were carried out using the peptide lactoferricin B (LfcinB), well known to be responsible for its antimicrobial activity. LfcinB significantly reduced (P ≤ 0.05) spoilage by a mean of 36% caused by three out of four inoculated spoiler pseudomonads on RTE lettuce leaves after six days of cold storage. The reduction in the extent of spoilage was unrelated to viable cell density in the inoculated wounds. This is the first paper providing direct evidence regarding the application of an antimicrobial peptide to control microbial spoilage affecting RTE leafy vegetables during cold storage.

  7. Changes of Bacterial Diversity Depend on the Spoilage of Fresh Vegetables

    Directory of Open Access Journals (Sweden)

    Dong Hwan Lee

    2011-04-01

    Full Text Available Almost 10~30% of vegetables were discarded by the spoilage from farms to tables. After harvest, vegetables are often spoiled by a wide variety of microorganisms including many bacterial and fungal species. This investigation was conducted to extent the knowledge of relationship the spoilage of vegetables and the diversity of microbes. The total aerobic bacterial numbers in fresh lettuce, perilla leaf, and chicory were 2.6~2.7×106, 4.6×105, 1.2×106 CFU/g of fresh weight, respectively. The most common bacterial species were Pseudomonas spp., Alysiella spp., and Burkholderia spp., and other 18 more genera were involved in. After one week of incubation of those vegetables at 28℃, the microbial diversity had been changed. The total aerobic bacterial numbers increased to 1.1~4.6×108, 4.9×107, and 7.6×108 CFU/g of fresh weight for lettuce, perilla leaf, and chicory that is about 102 times increased bacterial numbers than that before spoilage. However, the diversity of microbes isolated had been simplified and fewer bacterial species had been isolated. The most bacterial population (~48% was taken up by Pseudomonas spp., and followed by Arthrobacter spp. and Bacillus spp. The spoilage activity of individual bacterial isolates had been tested using axenic lettuce plants. Among tested isolates, Pseudomonas fluorescence and Pantoea agglomerans caused severe spoilage on lettuce.

  8. Antifungal effect of antimicrobial peptides (AMPs LR14) derived from Lactobacillus plantarum strain LR/14 and their applications in prevention of grain spoilage.

    Science.gov (United States)

    Gupta, Ruchi; Srivastava, Sheela

    2014-09-01

    The concern for food safety has led to an increased interest in the development of novel antimicrobials. Keeping this aim in mind, we have investigated the antifungal effect of antimicrobial peptides (AMPs LR14) produced by Lactobacillus plantarum strain LR/14 against four spoilage fungi, namely, Aspergillus niger, Rhizopus stolonifer, Mucor racemosus and Penicillium chrysogenum. Interestingly, all the four fungi were inhibited, suggesting that AMPs LR14 exhibited anti-fungal property. The peptides inhibited both, the spore germination and hyphal growth, however, the former stage was found to be more susceptible. The hyphal extensions were also inhibited in a dose-dependent manner. Viability test of treated spores confirmed the fungicidal activity of AMPs LR14. AMPs LR14 were also studied for the prevention of wheat grain spoilage under storage. Unhygienic conditions in damp godowns and store-houses, lead to loss of food grains and make them unfit for human consumption due to microbial deterioration. The treatment of wheat seeds with AMPs LR14 prevented fungal growth even after a prolonged storage under laboratory conditions for ∼2.5 years. The carbohydrate and protein content of the AMPs LR14-treated seeds denoted no significant loss, but the seed viability was affected as germination was retarded. Such studies have not been reported for any bacteriocin/AMP to the best of our knowledge. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Irradiation of foods

    International Nuclear Information System (INIS)

    Pai, J.S.

    2001-01-01

    Although irradiation is being investigated for the last more than 50 years for the application in preservation of food, it has not yet been exploited commercially in some countries like India. No other food processing technique has undergone such close scrutiny. There are many advantages to this process, which few others can claim. The temperature remains ambient during the process and the form of the food does not change resulting in very few changes in the sensory and nutritive quality of the food product. At the same time the microorganisms are effectively destroyed. Most of the spoilage and pathogenic organisms are sensitive to irradiation. Fortunately, most governments are supportive for the process and enacting laws permitting the process for foods

  10. Societal benefits of food irradiation

    International Nuclear Information System (INIS)

    Prakash, Anuradha

    2013-01-01

    Food irradiation has a direct impact on society by reducing the occurrence of food-borne illness, decreasing food spoilage and waste, and facilitating global trade. Food irradiation is approved in 40 countries around the world to decontaminate food of disease and spoilage causing microorganisms, sterilize insect pests, and inhibit sprouting. A recent estimate suggests that 500,000 metric of food is currently irradiated worldwide, primarily to decontaminate spices. Since its first use in the 1960s the use of irradiation for food has grown slowly, but it remains the major technology of choice for certain applications. The largest growth sector in recent years has been phytosanitary irradiation of fruit to disinfest fruit intended for international shipment. For many countries which have established strict quarantine standards, irradiation offers as an effective alternative to chemical fumigants some of which are being phased out due to their effects on the ozone layer. Insects can be sterilized at very low dose levels, thus quality of fruit can be maintained. Irradiation is also highly effective in destroying microbial pathogens such as Salmonella spp., E. coli, and Listeria, hence its application for treatment of spices, herbs, dried vegetables, frozen seafood, poultry, and meat and its contribution to reducing foodborne illnesses. Unfortunately the use of irradiation for improving food safety has been under-exploited. This presentation will provide details on the use, benefits, opportunities, and challenges of food irradiation. (author)

  11. The influence of Pichia killer toxins on the wine spoilage yeasts

    Directory of Open Access Journals (Sweden)

    Urszula Błaszczyk

    2015-08-01

    Full Text Available Killer yeasts are able to produce toxins that antagonize the growth of susceptible yeasts cells of the same species or the ones that are related to them. Killer strains are resistant to their own toxins but can be sensitive to killer proteins of other yeasts. The killer proteins of Pichia spp. are known for its broad spectrum of antifungal activity including pathogens such as Candida albicans. The aim of the study was to investigate the potential of the partly purified killer toxins to inhibit the growth of selected yeast strains which can contribute to wine spoilage. Three Pichia killer yeast strains (CBS 1982, CBS 5759, CBS 7373 were used in the study. The killer protein secreted by Pichia anomala CBS 1982 was characterized by the highest antifungal activity. The most pronounced effect of the reduction of cell proliferation by killer toxin preparations was found after 2 and 20 h cultivation. Among the 13 tested strains, all Pichia killer toxin preparations inhibited the growth of Rhodotorula graminis Rg, Rhodotorula mucilaginosa Rm and Schizosaccharomyces pombe DSM 70576. Killer toxins produced by Pichia anomala CBS 1982 (K8 and CBS 5759 (K4 limited the growth of Candida pulcherrima K5 and Hanseniaspora guillermondii DSM 3432 after 2, 20 and 168 h of incubation. A significant reduction of Debaryomyces hansenii DSM 3428 biomass was observed in medium with the addition of one toxin preparation (Pichia anomala CBS 1982. The growth limitation of Candida glabrata DSM 6425, Hanseniaspora uvarum DSM 2768, Metchnikowia pulcherrima DSM 70321 and Cryptococcus laurentii DSM 70766 was noticed only after 2 hours cultivation in presence of killer protein preparations. The killer toxins could be used in the food industry as selective tools to control infections during the fermentation of wine and improve the quality of the final product.

  12. Volatile components associated with bacterial spoilage of tropical prawns.

    Science.gov (United States)

    Chinivasagam, H N; Bremner, H A; Wood, A F; Nottingham, S M

    1998-06-30

    Analysis of headspace volatiles by gas chromatography/mass spectrometry from king (Penaeus plebejus), banana (P. merguiensis), tiger (P. esculentus/semisulcatus) and greasy (Metapenaeus bennettae) prawns stored in ice or ice slurry, which is effectively an environment of low oxygen tension, indicated the presence of amines at the early stages of storage (less than 8 days) irrespective of the nature of the storage media. Esters were more prevalent in prawns stored on ice (normal oxygen conditions) at the latter stages of storage (more than 8 days) and were only produced by Pseudomonas fragi, whereas sulphides and amines occurred whether the predominant spoilage organism was Ps. fragi or Shewanella putrefaciens. The free amino acid profiles of banana and king prawns were high in arginine (12-14%) and low in cysteine (0.1-0.17%) and methionine (0.1-0.2%). Filter sterilised raw banana prawn broth inoculated with a total of 15 cultures of Ps. fragi and S. putrefaciens and incubated for two weeks at 5 degrees C, showed the presence of 17 major compounds in the headspace volatiles analysed using gas chromatography/mass spectrometry (GC/MS). These were mainly amines, sulphides, ketones and esters. Principal Component Analysis of the results for the comparative levels of the volatiles produced by pure cultures, inoculated into sterile prawn broth, indicated three subgroupings of the organisms; I, Ps. fragi from a particular geographic location; II, S. putrefaciens from another geographic location; and III, a mixture of Ps. fragi and S. putrefaciens from different geographic locations. The sensory impression created by the cultures was strongly related to the chemical profile as determined by GC/MS. Organisms, even within the same subgrouping classified as identical by the usual tests, produced a different range of volatiles in the same uniform substrate.

  13. Metabolism of lactic acid in fermented cucumbers by Lactobacillus buchneri and related species, potential spoilage organisms in reduced salt fermentations

    Science.gov (United States)

    Recent evidence suggests that Lactobacillus buchneri may play an important role in spoilage-associated secondary fermentation of cucumbers. Lactic acid degradation during fermented cucumber spoilage is influenced by sodium chloride (NaCl) concentration, pH, and presence of oxygen. Objectives were to...

  14. Occurrence and growth of yeasts in processed meat products - implications for potential spoilage

    DEFF Research Database (Denmark)

    Nielsen, Dennis Sandris; Jacobsen, Tomas; Jespersen, Lene

    2008-01-01

    Spoilage of meat products is in general attributed to bacteria but new processing and storage techniques inhibiting growth of bacteria may provide opportunities for yeasts to dominate the microflora and cause spoilage of the product. With the aim of obtaining a deeper understanding of the potential...... role of yeast in spoilage of five different processed meat products (bacon, ham, salami and two different liver patés), yeasts were isolated, enumerated and identified during processing, in the final product and in the final product at the end of shelf life. Yeasts were isolated along the bacon...... of the processed meat products. The yeast microflora was complex with 4-12 different species isolated from the different production sites. In general, Candida zeylanoides, Debaryomyces hansenii and the newly described Candida alimentaria were found to be the dominant yeast species. In addition, three putatively...

  15. Spoilage of lightly salted lumpfish (Cyclopterus lumpus) roe at 5°C

    DEFF Research Database (Denmark)

    Basby, Merethe; Jeppesen, V.F.; Huss, Hans Henrik

    1998-01-01

    Lightly salted lumpfish roe (3.5–4.8% fw/w] salt in the water-phase, pH 5.4, vacuum-packed) was stored at 5°C. After 2 1/2 or 3 months of storage, different degrees of spoilage, caused by bacterial activity, occurred in eleven roe batches. Off-odors ranged from no or very weak odors to strong...... sulphury, sour odors. The microflora consisted of lactic acid bacteria, Enterobacteriaceae and Vibrio spp. Concentration of lactic acid, acetic acid, trimethylamine and total volatile bases were unrelated to spoilage odors. Volatile sulfur compounds (H2S, probably CS2, CH3SH and CH3CH2SH or CH3SCH3......), produced during storage, appeared to be contributors to spoilage odors....

  16. Seafood Spoilage Predictor - development and distribution of a product specific application software

    DEFF Research Database (Denmark)

    Dalgaard, Paw; Buch, P.; Silberg, Steen

    2002-01-01

    To allow shelf-life prediction of a range of products, the Seafood Spoilage Predictor (SSP) software has been developed to include both kinetic models for growth of specific spoilage microorganisms and empirical relative rates of spoilage models. SSP can read and evaluate temperature profile data...... of different formats and in this way the software is a flexible device for electronic time-temperature integration. Predicted values of microbial growth and of remaining product shelf life can be exported from SSP as graphs and tables in ASCII, HTML and eXtensible Mark-up Language (XML) formats and this allows...... SSP to be used in combination with other programmes. More than 300 people have downloaded SSP and distribution of this software from the internet has been efficient in stimulating the application of predictive microbiology and of mathematical seafood shelf-life models within industry, research...

  17. Use of an electronic nose for the early detection and differentiation between spoilage fungi.

    Science.gov (United States)

    Keshri, G; Magan, N; Voysey, P

    1998-11-01

    Six spoilage fungi (four Eurotium species, a Penicillium sp. and Wallemia sebi) were grown as spore lawn surface cultures at 0.95 water activity and 25 degrees C. Prior to and during visible growth (24 and 48, and 72 h), single cultures were enclosed in polyethylene bags, the head space was sampled with an electronic nose unit, consisting of 14 polymer sensors, and the data analysed. There was good replication between volatile patterns of the same species and using principal component, discriminant function and cluster analyses it was possible to differentiate between the agar blanks, three Eurotium spp., the Penicillium sp. and W. sebi during microscopic growth for the first time. This suggests that there is potential for the early detection of the activity of spoilage fungi in general, as well as possible differentiation between related xerophilic spoilage fungi, by detection of the patterns of volatile odours produced using an electronic nose system.

  18. Quorum Sensing in the Context of Food Microbiology

    Science.gov (United States)

    Skandamis, Panagiotis N.

    2012-01-01

    Food spoilage may be defined as a process that renders a product undesirable or unacceptable for consumption and is the outcome of the biochemical activity of a microbial community that eventually dominates according to the prevailing ecological determinants. Although limited information are reported, this activity has been attributed to quorum sensing (QS). Consequently, the potential role of cell-to-cell communication in food spoilage and food safety should be more extensively elucidated. Such information would be helpful in designing approaches for manipulating these communication systems, thereby reducing or preventing, for instance, spoilage reactions or even controlling the expression of virulence factors. Due to the many reports in the literature on the fundamental features of QS, e.g., chemistry and definitions of QS compounds, in this minireview, we only allude to the types and chemistry of QS signaling molecules per se and to the (bioassay-based) methods of their detection and quantification, avoiding extensive documentation. Conversely, we attempt to provide insights into (i) the role of QS in food spoilage, (ii) the factors that may quench the activity of QS in foods and review the potential QS inhibitors that might “mislead” the bacterial coordination of spoilage activities and thus may be used as biopreservatives, and (iii) the future experimental approaches that need to be undertaken in order to explore the “gray” or “black” areas of QS, increase our understanding of how QS affects microbial behavior in foods, and assist in finding answers as to how we can exploit QS for the benefit of food preservation and food safety. PMID:22706047

  19. Food irradiation nears commercial development

    International Nuclear Information System (INIS)

    1981-01-01

    One person out of eight in the world today suffers from chronic undernourishment. This problem is likely to get worse as the world's population doubles during the next thirty to forty years. Since about 25% or more of our harvested food is lost due to various kinds of wastage and spoilage, food preservation is no less important than food production. To supply the world's demand for food, it is more reasonable to conserve what is produced than to produce more to compensate for subsequent losses. Thus, it is obvious that all methods of preserving food and agricultural produce should be examined to see if their use might alleviate the world's food shortage, and that to develop better and safer techniques of food preservation will improve food supplies. Food preservation is an ever greater problem for the developing countries, not only because of their chronic problems of undernourishment, but also because most of them are in tropical or sub-tropical regions where food spoilage is rapid. The IAEA and the Food and Agriculture Organization (FAO) held a symposium on food irradiation at Colombo in Sri Lanka. The symposium paid special attention to the use of food irradiation in preserving tropical fruits as well as fish and fish products. It also examined the cost of the food irradiation process and compared it with those of conventional processes. Food irradiation is one field in which advance is most likely to be achieved through international co-operation. This co-operation has been supported by the IAEA and FAO in a number of ways. During the last 15 years three previous symposia (Karlsruhe, 1966; Bombay, 1972; Wageningen, 1977), numerous panel meetings, and training courses, have been held on this subject and many nations' food irradiation projects have been supported by technical assistance and co-ordinated research programmes

  20. Food preservation by irradiation

    International Nuclear Information System (INIS)

    1978-01-01

    As shortages of food and energy still continue to constitute the major threats to the well-being of the human race, all actions aiming at overcoming these problems must be assigned vital importance. Of the two complementary ways of solving the food problem (i.e., increasing the production of food and decreasing the spoilage of food) a novel method designed to contribute to the latter purpose has been discussed at this symposium hosted by The Netherlands and held under the aegis of the Food and Agriculture Organization of the United Nations, the International Atomic Energy Agency and the World Health Organization. Progress made since the last symposium of this kind (Bombay, India, 1972) was reviewed from the technological, economic and wholesomeness points of view by participants from 39 countries (60% of the latter were of the developing world). From the reports presented on the use of radiations to control physiological changes in plants, feasibility of radiation preservation of potatoes, onions, garlic, as well as of some tropical and subtropical fruits (mangoes, papayas, litchis and avocado) was confirmed. For potatoes, onions and mangoes, optimal conditions of treatment and storage were established on a larger scale, combined with sizeable consumer trials. Combinations of ionizing radiation with chemicals (salycilic acid, for potatoes), and physical agents (ultraviolet rays, for papayas) have been reported to be successful against the incidence of rot. A considerable number of papers dealt with the control of microbiological spoilage of foods. Work since 1972 has shown that radurization of fruits and vegetables (bananas, mangoes, dried dates, endive, chickory, onions, soup-greens), meat, poultry, marine products (mackerel, cod and plaice fillets, shrimps), decontamination of food ingredients and food technology aids (enzyme preparations, proteins, starch, spices), radappertization of meat and animal feedstuffs as well as combination treatments with salt, heat

  1. Inactivation of foodborne pathogenic and spoilage micro-organisms using ultraviolet-A light in combination with ferulic acid.

    Science.gov (United States)

    Shirai, A; Watanabe, T; Matsuki, H

    2017-02-01

    The low energy of UV-A (315-400 nm) is insufficient for disinfection. To improve UV-A disinfection technology, we evaluated the effect of ferulic acid (FA) addition on disinfection by UV-A light-emitting diode (LED) (350-385 nm) against various food spoilers and pathogens (seven bacteria and four fungi species). Photoantimicrobial assays were performed at FA concentrations below the MIC. The MIC of the isomerized FA, consisting of 93% cis-form and 7% trans-form, was very similar to that of the commercially available FA (trans-form). Irradiation with UV-A (1·0 J cm -2 ) in the presence of 100 mg l -1 FA resulted in enhanced reducing of all of the tested bacterial strains. A combination of UV-A (10 J cm -2 ) and 1000 mg l -1 FA resulted in enhanced reducing of Saccharomyces cerevisiae and one of the tested filamentous fungi. These results demonstrated that the combination of a short-term application of UV-A and FA at a low concentration yielded synergistic enhancement of antimicrobial activity, especially against bacteria. Microbial contamination is one of the most serious problems for foods, fruit and sugar thick juices. UV light is suitable for the nonthermal decontamination of food products by inactivating the contaminating micro-organisms. However, UV-A exposure is insufficient for disinfection. This study demonstrates that the combination of UV-A LED light (350-385 nm), which is not hazardous to human eyes and skin, and ferulic acid (FA), a known phytochemical and food additive, provides synergistic antimicrobial activity against foodborne pathogenic and spoilage micro-organisms. Therefore, FA addition to UV-A light treatment may be useful for improvement of UV-A disinfection technology to prevent food deterioration. © 2016 The Society for Applied Microbiology.

  2. A gaseous acetic acid treatment to disinfect fenugreek seeds and black pepper inoculated with pathogenic and spoilage bacteria.

    Science.gov (United States)

    Nei, Daisuke; Enomoto, Katsuyoshi; Nakamura, Nobutaka

    2015-08-01

    Contamination of spices by pathogenic and/or spoilage bacteria can be deleterious to consumer's health and cause deterioration of foods, and inactivation of such bacteria is necessary for the food industry. The present study examined the effect of gaseous acetic acid treatment in reducing Escherichia coli O157:H7, Salmonella Enteritidis and Bacillus subtilis populations inoculated on fenugreek seeds and black pepper. Treatment with gaseous acetic acid at 0.3 mmol/L, 0.6 mmol/L and 4.7 mmol/L for 1-3 h significantly reduced the populations of E. coli O157:H7 and Salmonella Enteritidis on black pepper and fenugreek seeds at 55 °C (p pathogens than the treatment at 0.3 mmol/L. An approximately 5.0 log reduction was obtained after 3 h of treatment with 4.7 mmol/L acetic acid. No significant reductions in the population of B. subtilis spores inoculated on fenugreek seeds and black pepper were obtained after the gas treatments at 0.3 mmol/L or 0.6 mmol/L (p > 0.05). However, the gas treatment at 4.7 mmol/L significantly reduced B. subtilis spores (p < 0.05), and 4.0 log CFU/g and 3.5 log CFU/g reductions on fenugreek seeds and black pepper, respectively, were obtained after 3 h of treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Food irradiation - A new way to process food

    International Nuclear Information System (INIS)

    1987-01-01

    The film shows how irradiation of food by ionizing energy (gamma rays or beams of electrons) can help cut down post-harvest losses of food such as cereals, meat, fish and shellfish and fresh or dried fruits and vegetables. One quarter to one third of the total world food production is lost due to sprouting, destruction by insects and parasites, spoilage by micro-organisms such as bacteria and funghi, and premature ripening. Food contamination not only leads to economic problems but can also cause diseases such as trichinosis, toxoplasmosis, etc. The new technique of food irradiation has been studied by independent groups of experts whose evaluations without exception have been favourable. One of the main advantages is that there are no chemical residues. On the long run, food irradiation will help to assure world-wide food security

  4. Determination of Spoilage Microbiota of Pacific White Shrimp During Ambient and Cold Storage Using Next-Generation Sequencing and Culture-Dependent Method.

    Science.gov (United States)

    Yang, Sheng-Ping; Xie, Jing; Qian, Yun-Fang

    2017-05-01

    This study was conducted to determine the initial and spoilage microbiota of Pacific white shrimp during ambient and cold storage using next-generation sequencing (NGS) and a culture-dependent method. The quality changes were also evaluated by sensory analysis and total volatile basic nitrogen (TVB-N) values. After 1 d of storage, the psychrotrophic bacteria were only 5.97 log CFU/g, accounting for 1.1% of the mesophilic bacteria counts (7.94 log CFU/g). The psychrotrophic bacteria counts exceeded the counts of mesophilic bacteria for shrimp stored at 4 °C after 6 d of storage, indicating that psychrotrophic bacteria became predominant. The NGS was used to identify the bacterial species in samples stored at 25 and 4 °C. The results showed that the dominant microorganisms were Vibrio at 25 °C, and Acinetobacter, Psychrobacter, and Shewanella at 4 °C. By the culture-dependent method based on 16S rRNA gene and VITEK®2 CompactA system, it showed that the dominant microorganisms were Proteus spp. at 25 °C, and Shewanella putrefaciens, Acinetobacter johnsonii, and Aeromonas sobria at 4 °C. In conclusion, differences in results of microbiota analyzed by culture dependent and independent approaches were observed. The combination of both methodologies may provide more comprehensive information about the dominant spoilage microbiota in Pacific white shrimp during ambient and cold storage. © 2017 Institute of Food Technologists®.

  5. Development of a model system for the study of spoilage associated secondary cucumber fermentation during long-term storage.

    Science.gov (United States)

    Franco, Wendy; Pérez-Díaz, Ilenys M

    2012-10-01

    Calcium chloride fermentations represent an alternative to reduce chloride concentrations in the wastewaters generated from commercial cucumber fermentations, currently performed in cover brine solutions containing 6% to 12% sodium chloride. However, preliminary attempts to commercially ferment the cucumbers in the presence of oxygen led to the development of a secondary cucumber fermentation or spoilage. The development of cucumber secondary fermentation has also been occasionally reported by processors using cover brine solutions containing sodium chloride. This study focused on the development of a model system to characterize CaCl(2) and NaCl secondary cucumber fermentations under conditions similar to those present on the commercial scale. Cucumber fruits mixed with cover brine solutions, containing 100 mM CaCl(2) or 1.03 M NaCl, and 25 mM acetic acid, were fermented in 2 L fermentation vessels subjected to air-purging at a rate of 5 mL/min. Microorganisms and selected biochemical changes detected in the experimental cucumber fermentations had been previously observed in commercial spoilage samples, suggesting the successful reproduction of the secondary fermentation in the laboratory. Experimental secondary fermentations were characterized by the rapid oxidation of the lactic acid produced during the primary fermentation, which, in turn, increased pH. Lactic acid disappearance seemed to be the result of yeast metabolism that also led to the chemical reduction of the environment to levels at which other bacteria could become established and produce butyric, propionic, and acetic acids. This model system will be applied for the identification of strategies to prevent the initiation of the cucumber secondary fermentation and reduce economic losses in the pickling industry. The study of secondary cucumber fermentation has represented a challenge for many years. The successful development of a model system for the study of this phenomenon in the laboratory is

  6. Involvement of bacterial quorum-sensing signals in spoilage of bean sprouts

    DEFF Research Database (Denmark)

    Rasch, Maria; Andersen, Jens Bo; Nielsen, Kristian Fog

    2005-01-01

    sprouts. Thin-layer chromatography and liquid chromatography-high-resolution mass spectrometry revealed the presence of N-3-oxo-hexanoyl-l-homoserine lactone in spoiled bean sprouts and in extracts from pure cultures of bacteria. During normal spoilage, the pH of the sprouts increased due to proteolytic...

  7. Development and validation of a colorimetric sensor array for fish spoilage monitoring

    DEFF Research Database (Denmark)

    Morsy, Mohamed K.; Zor, Kinga; Kostesha, Natalie

    2016-01-01

    their color changes in response to compounds present in fresh products (hexanal, 1-octane-3-ol) used as negative controls. The colorimetric sensor array was used to follow fish spoilage over time at room temperature for up to 24 h as well as at 4 °C for 9 days. Additionally, fish decay was monitored using...

  8. The occurrence of spoilage yeasts in cream-filled bakery products.

    Science.gov (United States)

    Osimani, Andrea; Milanović, Vesna; Taccari, Manuela; Cardinali, Federica; Pasquini, Marina; Aquilanti, Lucia; Clementi, Francesca

    2017-04-01

    Filling creams can provide an adequate substrate for spoilage yeasts because some yeasts can tolerate the high osmotic stress in these products. To discover the source of spoilage of a cream-filled baked product, end products, raw materials, indoor air and work surfaces were subjected to microbiological and molecular analyses. The efficacy of disinfectants against spoilage yeasts was also assessed. The analyses on end products revealed the presence of the closest relatives to Zygosaccharomyces bailii with counts ranging from 1.40 to 4.72 log cfu g -1 . No spoilage yeasts were found in the indoor air and work surfaces. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis, carried out directly on filling creams collected from unopened cans, showed the presence of bands ascribed to the closest relatives to Z. bailii sensu lato, although with counts < 1 log cfu g -1 . Susceptibility testing of yeast isolates to disinfectants showed a significantly lower effect of 10% alkyl dimethyl benzyl ammonium chloride. Different responses of isolates to the tested disinfectants were seen. To guarantee the quality of end products, reliable and sensitive methods must be used. Moreover, hygiene and the application of good manufacturing practices represent the most efficient way for the prevention and minimization of cross-contamination. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  9. Importance of Photobacterium phosphoreum in relation to spoilage of modified atmosphere-packed fish products

    DEFF Research Database (Denmark)

    Dalgaard, Paw; Mejlholm, Ole; Christiansen, T.J.

    1997-01-01

    products and the organism is likely to be of importance for spoilage of several modified atmosphere-packed (MAP) marine fish species when stored at chill temperatures. Some microbiological methods recommended for control of fish products by national and international authorities are inappropriate...

  10. Photocatalytic disinfection of spoilage bacteria Pseudomonas fluorescens and Macrococcus caseolyticus by nano-TiO2

    Science.gov (United States)

    Photocatalytic disinfection of spoilage bacteria gram-negative (G-) P. fluorescens and gram-positive (G+) M. caseolyticus by nano-TiO2 under different experimental conditions and the disinfection mechanism were investigated. The experimental conditions included the initial bacterial populations, nan...

  11. Spoilage of sous vide cooked salmon (Salmo salar) stored under refrigeration.

    Science.gov (United States)

    Díaz, P; Garrido, M D; Bañón, S

    2011-02-01

    The spoilage of Sous Vide 'SV' cooked salmon stored under refrigeration was studied. Samples were packaged under vacuum in polyamide-polypropylene pouches, cooked at an oven temperature/time of 80 (°)C/45 min, quickly chilled at 3 (°)C and stored at 2 (°)C for 0, 5 or 10 weeks for catering use. Microbial (aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae), physical-chemical (pH, water activity, TBARS, acidity, L*a*b* color, texture profile analysis and shear force) and sensory (appearance, odor, flavor, texture and overall quality) parameters were determined. SV processing prevented the growth of aerobic and anaerobic psychrotrophs, lactic acid bacteria, molds and yeasts and Enterobacteriaceae. There were no relevant changes in pH, water activity, TBARS, CIELab color associated with cooked salmon spoilage. Instrumental texture data were contradictory. Slight decrease in lactic acid levels was found. In contrast, the SV cooked salmon suffered considerable sensory deterioration during its refrigerated storage, consisting of severe losses of cooked salmon odor and flavor, slight rancidity, discoloration associated with white precipitation, and moderates softness, and loss of chewiness and juiciness. No acidification, putrefaction or relevant rancidity was detected. The sensory spoilage preceded microbiological and physical-chemical spoilage, suggesting that microbiological quality alone may overestimate the shelf life of SV cooked salmon.

  12. Effect of bacterial interactions on the spoilage of cold-smoked salmon.

    Science.gov (United States)

    Joffraud, Jean-Jacques; Cardinal, Mireille; Cornet, Josiane; Chasles, Jean-Sébastien; Léon, Sandrine; Gigout, Frédérique; Leroi, Françoise

    2006-10-15

    Cold-smoked salmon is a lightly preserved fish product in which a mixed microbial flora develops during storage and where the interactive behaviour of micro-organisms may contribute to their growth and spoilage activity. The aim of this study was to assess the effect of the bacterial interactions between the main species contaminating the cold-smoked salmon on bacterial growth, chemical and sensory changes, and spoilage. First, Carnobacterium piscicola, Photobacterium phosphoreum, Lactobacillus sakei, Vibrio sp., Brochothrix thermosphacta and Serratia liquefaciens-like were inoculated as pure cultures on sterile cold-smoked salmon. All bacterial species grew well; Vibrio sp. was the fastest and L. sakei strains developed very rapidly as well with a high maximum cell density on cold-smoked salmon blocks (up to 10(9) cfu g(-1) after 10 days at 8 degrees C). Based on sensory analysis, Vibrio sp. was identified as non-spoilage bacteria, C. piscicola as very lightly and B. thermosphacta as lightly spoiling. L. sakei and S. liquefaciens-like were found to be the most spoiling bacteria. Secondly, C. piscicola and L. sakei, two species frequently occurring in the lactic flora of the product, were inoculated together and each of them in mixed cultures with respectively P. phosphoreum, Vibrio sp., B. thermosphacta, and S. liquefaciens-like. The growth of L. sakei was shown to strongly inhibit most of the co-inoculated strains i.e. P. phosphoreum, B. thermosphacta, S. liquefaciens-like and, to a lesser extent, Vibrio sp. The growth of C. piscicola seemed to be enhanced with B. thermosphacta and to develop earlier with P. phosphoreum and Vibrio sp. Conversely, S. liquefaciens-like and P. phosphoreum were weakly inhibited by C. piscicola. The main observation resulting from the sensory evaluation was the delay in the appearance of the spoilage characteristics in the mixed cultures with L. sakei, in particular L. sakei/ S. liquefaciens-like. On the other hand, the spoilage

  13. Chemical composition and antimicrobial activity of essential oils from selected herbs cultivated in the South of Brazil against food spoilage and foodborne pathogens Composição química e atividade antimicrobiana de óleos essenciais de plantas selecionadas cultivadas no Sul do Brasil contra micro-organismos patogênicos e deteriorantes de alimentos

    Directory of Open Access Journals (Sweden)

    Sheila Mello da Silveira

    2012-07-01

    Full Text Available The chemical composition of 10 selected plant essential oils obtained by steam distillation was determined by GC and GC/MS. The antimicrobial activity of the essential oils was screened against 12 important food-related bacterial strains by agar disc-diffusion assay. MIC and MBC were determined for the essential oils that presented the highest activity in the agar disc-diffusion test. The most active essential oils against the tested bacteria were, in descending order, lemongrass (Cymbopogon flexuosus, basil (Ocimum basilicum, oregano (Origanum vulgare, cinnamon leaf (Cinnamomum zeylanicum, and laurel (Laurus nobilis. Except for S. Typhimurium, the tested bateria were inhibited at MIC values lower or equal to 0.62mg mL-1 by lemongrass (Cymbopogon flexuosus essential oil. Yersinia enterocolitica presented the highest sensitivity to all essential oils tested (CMI≤0.62mg mL-1. There was a significant correlation (PA composição química de 10 óleos essenciais obtidos por destilação a vapor foi determinada por CG/DIC e CG/EM. A atividade antimicrobiana dos óleos essenciais foi detectada através do método de difusão em ágar frente a 12 espécies de bactérias de importância em alimentos. As CMI e CMB foram determinadas para os óleos essenciais que na difusão em ágar evidenciaram maior atividade. Os óleos essenciais que apresentaram maior atividade contra as bactérias testadas foram, em ordem decrescente, os de capim-limão (Cymbopogon flexuosus, manjericão (Ocimum basilicum, orégano (Origanum vulgare, folha de canela (Cinnamomum zeylanicum e louro (Laurus nobilis. Com exceção de S. Typhimurium, o óleo essencial de capim limão (Cymbopogon flexuosus apresentou valores de CMI e CMB iguais ou inferiores a 0,62mg mL-1 contra os micro-organismos testados. Yersinia enterocolitica foi o patógeno mais sensível frente a todos os óleos essenciais avaliados (CMI≤0,62mg mL-1. Foi detectada correlação significativa (P<0,05 entre os n

  14. Knowledge and practices of food hygiene and safety among camel ...

    African Journals Online (AJOL)

    The respondents showed low knowledge in answering questions regarding spoilage microorganisms and effective cleaning of containers. About 53% of women retailers used rejected/spoiled milk for household consumption. This could result in a high food safety risk. Therefore, training of actors along the camel milk value ...

  15. Volatile sulfur compounds in foods as a result of ionizing radiation

    Science.gov (United States)

    Ionizing radiation improves food safety and extends shelf life by inactivating food-borne pathogens and spoilage microorganisms. However, irradiation may induce the development of an off-odor, particularly at high doses. The off-odor has been called “irradiation odor”. Substantial evidence suggests ...

  16. Trends in antimicrobial food packaging systems: Emitting sachets and absorbent pads

    Science.gov (United States)

    Active antimicrobial packaging interacts with packaged food and headspace to reduce, retard, or even inhibit the growth of spoilage and pathogenic microorganisms. Sachets and pads are one of the most successful applications of active food packaging. This review discusses recent developments of antim...

  17. Analysis of Growth Inhibition and Metabolism of Hydroxycinnamic Acids by Brewing and Spoilage Strains of Brettanomyces Yeast

    Science.gov (United States)

    Lentz, Michael; Harris, Chad

    2015-01-01

    Brettanomyces yeasts are well-known as spoilage organisms in both the wine and beer industries, but also contribute important desirable characters to certain beer styles. These properties are mediated in large part by Brettanomyces’ metabolism of hydroxycinnamic acids (HCAs) present in beverage raw materials. Here we compare growth inhibition by, and metabolism of, HCAs among commercial brewing strains and spoilage strains of B. bruxellensis and B. anomalus. These properties vary widely among the different strains tested and between the HCAs analyzed. Brewing strains showed more efficient metabolism of ferulic acid over p-coumaric acid, a trait not shared among the spoilage strains. PMID:28231223

  18. Analysis of Growth Inhibition and Metabolism of Hydroxycinnamic Acids by Brewing and Spoilage Strains of Brettanomyces Yeast

    Directory of Open Access Journals (Sweden)

    Michael Lentz

    2015-10-01

    Full Text Available Brettanomyces yeasts are well-known as spoilage organisms in both the wine and beer industries, but also contribute important desirable characters to certain beer styles. These properties are mediated in large part by Brettanomyces’ metabolism of hydroxycinnamic acids (HCAs present in beverage raw materials. Here we compare growth inhibition by, and metabolism of, HCAs among commercial brewing strains and spoilage strains of B. bruxellensis and B. anomalus. These properties vary widely among the different strains tested and between the HCAs analyzed. Brewing strains showed more efficient metabolism of ferulic acid over p-coumaric acid, a trait not shared among the spoilage strains.

  19. Technology of food preservation by irradiation

    International Nuclear Information System (INIS)

    Thomas, Paul

    1997-01-01

    Food Technology Division, Bhabha Atomic Research Centre, Mumbai has demonstrated that radiation processing of foods can contribute to nations food security by reducing post-harvest losses caused by insect infestation, microbial-spoilage and physiological changes. The technology has commercial potential for the conservation of cereals, pulses and their products, spices, onions, potatoes, garlic, some tropical fruits, sea foods, meat and poultry. Irradiation can ensure hygienic quality in foods including frozen foods by eliminating food borne pathogens and parasitic organisms. It offers a viable environment friendly alternative to chemical fumigants for quarantine treatment against insect pests in agricultural and horticultural products entering international trade. The safety and nutritional adequacy of irradiated foods for human consumption is well established. About 40 countries including India have regulations permitting irradiation of foods and 28 countries are irradiating foods for processing industries and institutional catering

  20. Biodegradation of endosulfan by a soil bacterium.

    Science.gov (United States)

    Shivaramaiah, H M; Kennedy, I R

    2006-01-01

    A bacterium capable of metabolizing endosulfan (6,7,8,9,10,10-hexachloro-1,5,5a,6,9,9a-hexahydro-6,9-methano-2,4,3-benzodioxathiepine3-oxide) was isolated from cotton-growing soil and effectively shown to degrade endosulfan into endosulfan sulfate. The bacterium degraded 50% of the compound within 3 days of incubation. Endosulfan sulfate was the only terminal product and no other metabolites were formed during the incubation. Endosulfan and its metabolites were analyzed by gas chromatography. The metabolites formed indicated that the organism follows an oxidative pathway for metabolism of this pesticide. Therefore, the present study, microbial degradation of endosulfan by a soil bacterium, may provide a basis for the development of bioremediation strategies to remediate the pollutants in the environment.

  1. Zygosaccharomyces kombuchaensis: the physiology of a new species related to the spoilage yeasts Zygosaccharomyces lentus and Zygosaccharomyces bailii.

    Science.gov (United States)

    Steels, Hazel; James, Steve A; Bond, Chris J; Roberts, Ian N; Stratford, Malcolm

    2002-05-01

    Zygosaccharomyces kombuchaensis was recently discovered in the 'tea fungus' used to make fermented tea. Z. kombuchaensis was shown by ribosomal DNA sequencing to be a novel species, and a close relative of Zygosaccharomyces lentus, from which it could not be distinguished by conventional physiological tests. Z. lentus was originally established as a new taxon by growth at 4 degrees C, sensitivity for heat and oxidative stress, and lack of growth in aerobic shaken culture at temperatures above 25 degrees C. Subsequent analysis of Z. kombuchaensis reveals that this species shares these unusual characteristics, confirming its close genealogical relationship to Z. lentus. Detailed physiological data from a number of Z. kombuchaensis and Z. lentus strains clearly demonstrate that these two species can in fact be distinguished from one another based on their differing resistance/sensitivity to the food preservatives benzoic acid and sorbic acid. The spoilage yeasts Zygosaccharomyces bailii and Z. lentus are resistant to both acetic acid and sorbic acid, whereas Z. kombuchaensis is resistant to acetic acid but sensitive to sorbic acid. This would indicate that Z. kombuchaensis strains lack the mechanism for resistance to sorbic acid, but possess the means of resistance to acetic acid. This observation would therefore suggest that these two resistance mechanisms are different, and that in all probability acetic and sorbic acids inhibit yeast growth by different modes of action. Z. kombuchaensis strains were also sensitive to benzoic acid, again suggesting inhibition dissimilar from that to acetic acid.

  2. Anti-bacteria effect of active ingredients of siraitia grosvenorii on the spoilage bacteria isolated from sauced pork head meat

    Science.gov (United States)

    Li, X.; Xu, L. Y.; Cui, Y. Q.; Pang, M. X.; Wang, F.; Qi, J. H.

    2018-01-01

    Extraction and anti-bacteria effect of active ingredients of Siraitia grosvenorii were studied in this paper. Extraction combined with ultrasonic was adopted. The optimum extraction condition was determined by single factor test; the anti-bacteria effect of active ingredients and minimum inhibitory concentration (MIC) were valued by Oxford-cup method. The results indicated that optimum extraction condition of active ingredients extracted from Siraitia grosvenorii were described as follows: ethanol concentrations of sixty-five percent and twenty minutes with ultrasonic assisted extraction; the active ingredients of Siraitia grosvenorii had anti-bacteria effect on Staphylococcus epidermidis, Proteus vulgaris, Bacillus sp, Serratia sp and MIC was 0.125g/mL, 0.0625g/mL, 0.125g/mL and 0.125g/mL. The active constituent of Siraitia grosvenorii has obvious anti-bacteria effect on the spoilage bacteria isolated from Sauced pork head meat and can be used as a new natural food preservation to prolong the shelf-life of Low-temperature meat products.

  3. In vitro antifungal effect of black cumin seed quinones against dairy spoilage yeasts at different acidity levels.

    Science.gov (United States)

    Halamova, Katerina; Kokoska, Ladislav; Flesar, Jaroslav; Sklenickova, Olga; Svobodova, Blanka; Marsik, Petr

    2010-12-01

    The antiyeast activity of the black cumin seed (Nigella sativa) quinones dithymoquinone, thymohydroquinone (THQ), and thymoquinone (TQ) were evaluated in vitro with a broth microdilution method against six dairy spoilage yeast species. Antifungal effects of the quinones were compared with those of preservatives commonly used in milk products (calcium propionate, natamycin, and potassium sorbate) at two pH levels (4.0 and 5.5). THQ and TQ possessed significant antiyeast activity and affected the growth of all strains tested at both pH levels, with MICs ranging from 8 to 128 μg/ml. With the exception of the antibiotic natamycin, the inhibitory effects of all food preservatives against the yeast strains tested in this study were strongly affected by differences in pH, with MICs of ≥16 and ≥512 μg/ml at pH 4.0 and 5.5, respectively. These findings suggest that HQ and TQ are effective antiyeast agents that could be used in the dairy industry as chemical preservatives of natural origin.

  4. Production Method that Leads to TiO2 Nanofibrous Structure Usable in Food Packaging

    Directory of Open Access Journals (Sweden)

    Kovář Radovan

    2016-12-01

    Full Text Available Burned inorganic nanofibers most often occur in the nature in two forms: rutile and anatase. Today, the production of rutile is about to end, while anatase provides more application possibilities. The resulting fiber structure is determined by calcination. It is necessary to find the optimal temperature as well as time, during which the fibers must withstand temperature load. For such method of calcination, it is necessary to create a special design of continuous furnace. Anatase has application in food packaging. Packages containing anatase are used for: food safety, improved packaging for spoilage reduction, sensors for detection of pathogens and spoilage, disinfectants and antimicrobial surfaces.

  5. Evaluation of the spoilage potential of bacteria isolated from spoiled raw salmon (Salmo salar) fillets stored under modified atmosphere packaging.

    Science.gov (United States)

    Macé, Sabrina; Joffraud, Jean-Jacques; Cardinal, Mireille; Malcheva, Mariya; Cornet, Josiane; Lalanne, Valérie; Chevalier, Frédérique; Sérot, Thierry; Pilet, Marie-France; Dousset, Xavier

    2013-01-01

    The spoilage potential of eight bacterial groups/species (Serratia spp., Hafnia alvei, Brochothrix thermosphacta, Carnobacterium maltaromaticum, Shewanella baltica, Lactococcus piscium, Photobacterium phosphoreum, "other Enterobacteriaceae" [containing one strain of Moellerella sp., Morganella sp. and Pectobacterium sp.]) isolated from spoiled raw salmon fillets stored under modified atmosphere packaging (MAP) was evaluated by inoculation into sterile raw salmon cubes followed by storage for 12days at 8°C. Microbial growth and sensory changes were monitored during the storage period. The dominant spoilage bacteria were C. maltaromaticum, H. alvei and P. phosphoreum. In order to further characterize their spoilage potential and to study the effect of their interactions, each of these 3 specific spoilage organisms (SSO) and two mixed-cultures, C. maltaromaticum/H. alvei and C. maltaromaticum/P. phosphoreum were tested in the sterile salmon model system using a combination of complementary methods: molecular (PCR-TTGE), sensory, chemical and conventional microbiological analyses. It was concluded that, in the mixed-culture inoculated samples, the dominant species determined the spoilage characteristics. The volatile fraction of P. phosphoreum inoculated samples was analyzed by solid-phase microextraction (SPME) followed by gas chromatography coupled to mass spectrometry (GC-MS). Among the specific volatile compounds present on P. phosphoreum spoiled inoculated samples, acetic acid was correlated with sensory analysis and can be proposed as a raw salmon spoilage marker. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Acetic acid induces a programmed cell death process in the food spoilage yeast Zygosaccharomyces bailii.

    Science.gov (United States)

    Ludovico, Paula; Sansonetty, Filipe; Silva, Manuel T; Côrte-Real, Manuela

    2003-03-01

    Here we show that 320-800 mM acetic acid induces in Zygosaccharomyces bailii a programmed cell death (PCD) process that is inhibited by cycloheximide, is accompanied by structural and biochemical alterations typical of apoptosis, and occurs in cells with preserved mitochondrial and plasma membrane integrity (as revealed by rhodamine 123 (Rh123) and propidium iodide (PI) staining, respectively). Mitochondrial ultrastructural changes, namely decrease of the cristae number, formation of myelinic bodies and swelling were also seen. Exposure to acetic acid above 800 mM resulted in killing by necrosis. The occurrence of an acetic acid-induced active cell death process in Z. bailii reinforces the concept of a physiological role of the PCD in the normal yeast life cycle.

  7. Identification of spoilage yeasts in a food-production chain by microsatellite polymerase chain reaction fingerprinting

    NARCIS (Netherlands)

    Baleiras Couto, M.M.; Hartog, B.J.; Veld, J.H.J. Huis in 't; Hofstra, H.; Vossen, J.M.B.M. van der

    1996-01-01

    A survey of yeast strains present in the production chain of mayonnaise and salad dressings was carried out over a period of 14 months. Attempts were made to identify the isolated yeasts with the API system, but identification of all species involved was not possible. In the investigation the

  8. Zymomonas mobilis: a bacterium for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Baratti, J.C.; Bu' Lock, J.D.

    1986-01-01

    Zymomonas mobilis is a facultative anaerobic gram negative bacterium first isolated in tropical countries from alcoholic beverages like the African palm wine, the Mexican pulque and also as a contaminant of cider (cider sickness) or beer in the European countries. It is one of the few facultative anaerobic bacteria degrading glucose by the Entner-Doudoroff pathway usually found in strictly aerobic microorganisms. Some work was devoted to this bacterium in the 50s and 60s and was reviewed by Swings and De Ley in their classical paper published in 1977. During the 70s there was very little work on the bacterium until 1979 and the first report by the Australian group of P.L. Rogers on the great potentialities of Z. mobilis for ethanol production. At that time the petroleum crisis had led the developed countries to search for alternative fuel from renewable resources. The Australian group clearly demonstrated the advantages of the bacterium compared to the yeasts traditionally used for the alcoholic fermentation. As a result, there was a considerable burst in the Zymomonas literature which started from nearly zero in the late 70s to attain 70 papers published in the field in 1984. In this article, papers published from 1982 to 1986 are reviewed.

  9. Kinetics of biofilm formation and desiccation survival of Listeria monocytogenes in single and dual species biofilms with Pseudomonas fluorescens, Serratia proteamaculans or Shewanella baltica on food-grade stainless steel surfaces.

    Science.gov (United States)

    Daneshvar Alavi, Hessam Edin; Truelstrup Hansen, Lisbeth

    2013-01-01

    This study investigated the dynamics of static biofilm formation (100% RH, 15 °C, 48-72 h) and desiccation survival (43% RH, 15 °C, 21 days) of Listeria monocytogenes, in dual species biofilms with the common spoilage bacteria, Pseudomonas fluorescens, Serratia proteamaculans and Shewanella baltica, on the surface of food grade stainless steel. The Gram-negative bacteria reduced the maximum biofilm population of L. monocytogenes in dual species biofilms and increased its inactivation during desiccation. However, due to the higher desiccation resistance of Listeria relative to P. fluorescens and S. baltica, the pathogen survived in greater final numbers. In contrast, S. proteamaculans outcompeted the pathogen during the biofilm formation and exhibited similar desiccation survival, causing the N21 days of Serratia to be ca 3 Log10(CFU cm(-2)) greater than that of Listeria in the dual species biofilm. Microscopy revealed biofilm morphologies with variable amounts of exopolymeric substance and the presence of separate microcolonies. Under these simulated food plant conditions, the fate of L. monocytogenes during formation of mixed biofilms and desiccation depended on the implicit characteristics of the co-cultured bacterium.

  10. Effects of dietary rosemary extract on lamb spoilage under retail display conditions.

    Science.gov (United States)

    Bañón, Sancho; Méndez, Lorena; Almela, Elisabet

    2012-03-01

    A dietary rosemary extract (RE) was tested to extend the shelf life of raw lamb meat. Lambs were supplemented with 0.6mgkg(-1) RE during fattening (from 13 to 25kg live weight). Meat spoilage (total viable counts, psycrophilic bacteria, Enterobacteriaceae, molds and yeasts), TBARS, CIE L*a*b* color and the sensory traits of lamb cuts were analyzed on days 0, 7, 14 or 21 under retail display conditions (70/30 O(2)/CO(2) atmosphere, 2°C temperature and 1600lx lighting). Supplementation of the lamb diet with RE was effective (Pretail display conditions. Dietary rosemary clearly inhibited lipid oxidation and rancidity, and was moderately efficient in preventing sensory deterioration and microbial spoilage. Although the results concerning meat preservation were limited, the dietary use of rosemary extracts in lambs seems to be promising as a nutritional strategy for improving meat quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

  11. The Challenges of Eliminating or Substituting Antimicrobial Preservatives in Foods.

    Science.gov (United States)

    Erickson, Marilyn C; Doyle, Michael P

    2017-02-28

    Consumers' criteria for evaluating food safety have evolved recently from considering the food's potential to cause immediate physical harm to considering the potential long-term effects that consumption of artificial ingredients, including antimicrobial preservatives, would have on health. As bacteriostatic and bactericidal agents to prevent microbial spoilage, antimicrobials not only extend shelf life, but they also enhance the product's safety. Antimicrobials and their levels that may be used in foods are specified by regulatory agencies. This review addresses the safety of antimicrobials and the potential consequences of removing those that are chemically synthesized or replacing them with antimicrobials from so-called natural sources. Such changes can affect the microbiological safety and spoilage of food as well as reduce shelf life, increase wastage, and increase the occurrence of foodborne illnesses.

  12. The Spoilage Yeast Zygosaccharomyces bailii Forms Mitotic Spores: a Screening Method for Haploidization

    OpenAIRE

    Rodrigues, Fernando; Ludovico, Paula; Sousa, Maria João; Steensma, H. Yde; Côrte-Real, Manuela; Leão, Cecília

    2003-01-01

    Zygosaccharomyces bailii ISA 1307 and the type strain of this spoilage yeast show a diploid DNA content. Together with a rather peculiar life cycle in which mitotic but no meiotic spores appear to be formed, the diploid DNA content explains the observed difficulties in obtaining auxotrophic mutants. Mitotic chromosome loss induced by benomyl and selection on canavanine media resulted in three haploid strains of Z. bailii. This new set of Z. bailii strains allows the easy isolation...

  13. Effect of microbial cell-free meat extract on the growth of spoilage bacteria.

    Science.gov (United States)

    Nychas, G-J E; Dourou, D; Skandamis, P; Koutsoumanis, K; Baranyi, J; Sofos, J

    2009-12-01

    This study examined the effect of microbial cell-free meat extract (CFME) derived from spoiled meat, in which quorum sensing (QS) compounds were present, on the growth kinetics (lag phase, and growth rate) of two spoilage bacteria, Pseudomonas fluorescens and Serratia marcescens. Aliquots of CFME from spoiled meat were transferred to Brain Heart Infusion broth inoculated with 10(3) CFU ml(-1) of 18 h cultures of Ps. fluorescens or Ser. marcescens, both fresh meat isolates; CFME derived from unspoiled fresh meat ('clean' meat) served as a control. Changes in impedance measurements were monitored for 48 h, and the detection time (Tdet) was recorded. It was found that in the absence of CFME containing QS compounds the Tdet was shorter (P meat. The rate of growth of Ps. fluorescens, recorded as the maximum slope rate of conductance changes (MSrCC), after Tdet, was higher (P meat. Similar results in MSrCC of impedance changes were obtained for Ser. marcescens. The study indicated that the growth rate (expressed in MSrCC units) of meat spoilage bacteria in vitro was enhanced in samples supplemented with CFME containing QS compounds compared to control samples (i.e., without CFME or with CFME from 'clean' meat). This behaviour may explain the dominant role of these two bacteria in the spoilage of meat. These results illustrate the potential effect of signalling compounds released during storage of meat on the behaviour of meat spoilage bacteria. Understanding such interactions may assist in the control of fresh meat quality and the extension of its shelf life.

  14. Spoilage-related microbiota associated with chilled beef stored in air or vacuum pack.

    Science.gov (United States)

    Pennacchia, C; Ercolini, D; Villani, F

    2011-02-01

    In order to study the spoilage-related microbiota of beef at species level, a combination of culture-independent and culture-dependent methods was used to analyse nine different beef samples stored at 4°C in air or in vacuum pack. Plate counts on selective agars after 0, 7 and 20 days of storage showed that vacuum packaging reduced the viable counts of Brochothrix thermosphacta, Pseudomonas spp. and Enterobacteriaceae, whereas the growth of lactic acid bacteria (LAB) was unaffected. Storage in vacuum pack mainly affected viable counts and not necessarily the species diversity of microbial populations on meat. Such populations were studied by PCR-DGGE of DNA directly extracted from meat and from bulk cells from culture media, followed by sequencing of DGGE fragments. Pseudomonas spp., Carnobacterium divergens, B. thermosphacta, Rahnella spp. and Serratia grimesii, or close relatives were detected in the meat at time zero. The use of the culture-independent method highlighted the occurrence of species that were not detected by plating. Photobacterium spp. occurred in most meat samples stored in air or in vacuum pack, which indicates this organism probably has a role in spoilage. In contrast, culture-dependent analysis allowed detection of bacterial species that were not found in DNA extracted directly from meat. This was the case for several species of Serratia or Rhanella among the enterobacteria, and Leuconostoc spp. among the LAB. Besides advancing our knowledge of the species involved in the spoilage of vacuum-packaged meat, this study shows the benefits of combining culture-based and direct approaches to enhance understanding of populations of spoilage bacteria. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Reduction of spoilage of chilled vacuum-packed lamb by psychrotolerant clostridia.

    Science.gov (United States)

    Adam, Katharine H; Flint, Steve H; Brightwell, Gale

    2013-02-01

    Methods for the reduction of spoilage, of lamb, by psychrotolerant clostridia were investigated including exposure to air, hot and cold water spray washing and tyndallisation. Initially vegetative cells of psychrotolerant clostridia associated with spoilage of chilled vacuum-packed meat were exposed to aerobic cooked meat medium at room temperature (21 °C) to determine how long they remained viable. Survival of strains varied from 2h to 3 days. Vegetative cells of Clostridium estertheticum subsp. estertheticum survived 7 days at 10 °C with little reduction in viable numbers. This ruled out exposure to air as a practical method for reducing spoilage. Trials were also carried out on chilled vacuum-packed lamb inoculated with spores of Cl. estertheticum subsp. estertheticum. The time until inoculated packs reached the loss of vacuum stage varied from 38 to 53 days. Hot and cold water washing extended the shelf life by 12 to 13 days in comparison to untreated packs. Copyright © 2012 Elsevier Ltd. All rights reserved.

  16. Non-destructive detection of fish spoilage using a wireless basic volatile sensor.

    Science.gov (United States)

    Bhadra, Sharmistha; Narvaez, Claudia; Thomson, Douglas J; Bridges, Greg E

    2015-03-01

    A hydrogel-pH-electrode based near-field passive volatile sensor is described for real-time monitoring of fish spoilage. The sensor employs a varactor-based LC resonator that can be interrogated remotely using inductive coupling. The sensor's resonant frequency varies in response to the basic volatile spoilage compounds (total volatile basic nitrogen, TVB-N) in the headspace of packaged fish. The sensor is shown to have a linear response to logarithm of the ammonia gas concentration with a detection limit of 0.001 mg L(-1) (1.5 ppm). Trials on tilapia at 24 °C and 4 °C, employing direct comparison of sensor measurements with microbial analysis, indicate that the sensor response is correlated with the bacterial growth pattern in fish samples. It is shown that the sensor can distinctly identify when the product rejection level (10(7) cfu g(-1) bacterial population) occurs for both 24 °C and 4 °C storage conditions. This demonstrates a potential for real-time monitoring of fish spoilage. The wireless sensor is suited to embedding in packaging material and does not require an integrated circuit, making it amenable to inexpensive mass production using printed electronic technology. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Sour rot-damaged grapes are sources of wine spoilage yeasts.

    Science.gov (United States)

    Barata, André; González, Sara; Malfeito-Ferreira, Manuel; Querol, Amparo; Loureiro, Virgílio

    2008-11-01

    Yeast species of sound and sour rot-damaged grapes were analysed during fermentation and grape ripening in the vineyard, using general and selective culture media. During 2003 and 2004 vintages, microvinifications were carried out with sound grapes to which different amounts of grapes with sour rot were added. The wine spoilage species Zygosaccharomyces bailii was only recovered during fermentations with sour rot, reaching 5.00 log CFU mL(-1) (2003) and 2.48 log CFU mL(-1) (2004) at the end of fermentation. The study of yeast populations during the sour rot ripening process (2005 vintage) showed that the veraison-damaged grapes always exhibited higher total yeast counts and a much greater diversity of species. From a total of 22 ascomycetous species, 17 were present only in damaged grapes. The most frequent species were Issatchenkia occidentalis and Zygoascus hellenicus. The spoilage species Z. bailii and Zygosaccharomyces bisporus were consistently isolated exclusively from damaged grapes. This work demonstrates that one of the most dangerous wine spoilage species, Z. bailii, is strongly associated with sour rot grapes and survives during fermentation with Saccharomyces cerevisiae. The use of selective media provides a more accurate characterization of grape contamination species.

  18. Status of food irradiation in Pakistan

    International Nuclear Information System (INIS)

    Wahid, M.; Sattar, A.; Khan, I.

    1985-01-01

    Radiation preservation of various foods was studied. Optimum radiation-doses were established for controlling insect infestation, reducing microbial spoilage, extending storage life, delaying ripening of fresh fruits or vegetables and increasing nutritional value through sprouting of seeds. Influence of radiation physico-chemical properties and nutrients as well as antinutrients of foods was studied. Technical feasibility of radiation preservation of several food materials was established. Commercial trials on radiation preservation of potatoes were completed and cost economics calculated. The results of these findings have briefly been described. (authors)

  19. Food irradiation: current problems and future potential

    International Nuclear Information System (INIS)

    Kilcast, D.

    1995-01-01

    Food irradiation is one of a set of processing technologies that can be used to increase the microbiological safety and shelf-life of a wide range of foods. Ionizing radiation is used to generate highly active chemical species within the food, which react with DNA. Under normal usage conditions, the food receives a pasteurizing treatment that gives a valuable reduction in common food-spoilage organisms and food pathogens. This review describes how the process is used in practice, including the benefits and limitations. The nature of changes to food components are outlined, together with the development of practical detection methods that utilize these changes. The legislative position of food irradiation is outlined, with the specific example of the introduction of the technology within the UK. The reasons for the slow uptake in the use of the technology are discussed, and the problem of consumer acceptance is addressed. (author)

  20. Proceedings of a seminar on food irradiation

    International Nuclear Information System (INIS)

    1985-07-01

    International interest in the industrial use of ionizing radiation as a means of food preservation has increased rapidly following the favourable outcome of many years of intensive research on the health implications of food irradiation. The introduction in the U.S. and elsewhere of legislation restricting the use of chemical additives to foods for both human and animal consumption has contributed to this development. A high priority must be given to coordinating legislation on food irradiation within the European Community if international trade in irradiated foods is to make progress and food losses by spoilage and by insect infestation are to be minimised. Speakers from the United Kigdom, France and Germany describe the legislative and developmental situation in their respective countries. The implication for the Irish food industry is presented by scientists working on food research and development and regulatory aspects in Ireland are also discussed

  1. Extreme Ionizing-Radiation-Resistant Bacterium

    Science.gov (United States)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2013-01-01

    There is a growing concern that desiccation and extreme radiation-resistant, non-spore-forming microorganisms associated with spacecraft surfaces can withstand space environmental conditions and subsequent proliferation on another solar body. Such forward contamination would jeopardize future life detection or sample return technologies. The prime focus of NASA s planetary protection efforts is the development of strategies for inactivating resistance-bearing micro-organisms. Eradi cation techniques can be designed to target resistance-conferring microbial populations by first identifying and understanding their physiologic and biochemical capabilities that confers its elevated tolerance (as is being studied in Deinococcus phoenicis, as a result of this description). Furthermore, hospitals, food, and government agencies frequently use biological indicators to ensure the efficacy of a wide range of radiation-based sterilization processes. Due to their resistance to a variety of perturbations, the nonspore forming D. phoenicis may be a more appropriate biological indicator than those currently in use. The high flux of cosmic rays during space travel and onto the unshielded surface of Mars poses a significant hazard to the survival of microbial life. Thus, radiation-resistant microorganisms are of particular concern that can survive extreme radiation, desiccation, and low temperatures experienced during space travel. Spore-forming bacteria, a common inhabitant of spacecraft assembly facilities, are known to tolerate these extreme conditions. Since the Viking era, spores have been utilized to assess the degree and level of microbiological contamination on spacecraft and their associated spacecraft assembly facilities. Members of the non-sporeforming bacterial community such as Deinococcus radiodurans can survive acute exposures to ionizing radiation (5 kGy), ultraviolet light (1 kJ/m2), and desiccation (years). These resistive phenotypes of Deinococcus enhance the

  2. Stereo and scanning electron microscopy of in-shell Brazil nut (Bertholletia excelsa H.B.K.): part two-surface sound nut fungi spoilage susceptibility.

    Science.gov (United States)

    Scussel, Vildes M; Manfio, Daniel; Savi, Geovana D; Moecke, Elisa H S

    2014-11-01

    This work reports the in-shell Brazil nut spoilage susceptible morpho-histological characteristics and fungi infection (shell, edible part, and brown skin) through stereo and scanning electron microscopies (SEM). The following characteristics related to shell (a) morphology-that allow fungi and insects' entrance to inner nut, and (b) histology-that allow humidity absorption, improving environment conditions for living organisms development, were identified. (a.1) locule in testae-the nut navel, which is a cavity formed during nut detaching from pods (located at 1.0 to 2.0/4th of the shell B&C nut faces linkage). It allows the nut brown skin (between shell and edible part) first contact to the external environment, through the (a.2) nut channel-the locule prolongation path, which has the water/nutrients cambium function for their transport and distribution to the inner seed (while still on the tree/pod). Both, locule followed by the channel, are the main natural entrance of living organisms (fungi and insects), including moisture to the inner seed structures. In addition, the (a.3) nut shell surface-which has a crinkled and uneven surface morphology-allows water absorption, thus adding to the deterioration processes too. The main shell histological characteristic, which also allows water absorption (thus improving environment conditions for fungi proliferation), is the (b.1) cell wall porosity-the multilayered wall and porous rich cells that compose the shell faces double tissue layers and the (b.2) soft tissue-the mix of tissues 2 faces corner/linkage. This work also shows in details the SEM nut spoilage susceptible features highly fungi infected with hyphae and reproductive structures distribution. © 2014 Institute of Food Technologists®

  3. Irradiated food: too hot to handle?

    International Nuclear Information System (INIS)

    Coghlan, Andy.

    1990-01-01

    This article discusses current arguments for and against the irradiation of food for human consumption. The technique, which involves bombarding batches of food with gamma rays, x rays or accelerated electrons, is claimed to halt spoilage, kill bacteria and thus extend the shelf-life of various foodstuffs. Irradiated foods are at present indistinguishable from non-irradiated food and this problem may not be solved before the government's bill legalizes the process. Opponents claim the technique may not be safe and that the food industry may use it to fool consumers into buying rotten foods. Proponents say that even though many foods, such as poultry, seafood, fruits, vegetables and spices may be treated, it is unlikely that more than a small proportion will be. They reject safety worries as alarmist exaggeration. (UK)

  4. A new strategy for inhibition of the spoilage yeasts Saccharomyces cerevisiae and Zygosaccharomyces bailii based on combination of a membrane-active peptide with an oligosaccharide that leads to an impaired glycosylphosphatidylinositol (GPI)-dependent yeast wall protein layer.

    Science.gov (United States)

    Bom, I J; Klis, F M; de Nobel, H; Brul, S

    2001-12-01

    Glycosylphosphatidylinositol (GPI)-dependent cell wall proteins in yeast are connected to the beta-1,3-glucan network via a beta-1,6-glucan moiety. Addition of gentiobiose or beta-1,6-glucan oligomers to growing cells affected the construction of a normal layer of GPI-dependent cell wall proteins at the outer rim of the Saccharomyces cerevisiae cell wall. Treated S. cerevisiae cells secreted significant amounts of cell wall protein 2, were much more sensitive to the lytic action of zymolyase 20T and displayed a marked increase in sensitivity to the small amphipathic antimicrobial peptide MB-21. Similar results in terms of sensitization of yeast cells to the antimicrobial peptide were obtained with the notorious food spoilage yeast Zygosaccharomyces bailii. Our results indicate that treating cells with a membrane-perturbing compound together with compounds that lead to an impaired construction of a normal GPI-dependent yeast wall protein layer represents an effective strategy to prevent the growth of major food spoilage yeasts.

  5. Laboratory and Field Evaluation of a Waterless Food Service Sanitation System Used by Military Mobile Kitchen Trailer Crews

    Science.gov (United States)

    1993-12-01

    then incubated at 35°C for 24 hours to encourage bacterial growth and food spoilage . Counts in the spoiled food exceeded 10’/g. bReduction was...severalfood poisoning bacteria by more than six logs. In the field, all surfaces of food -serving utensils and equipment examined were monitored for bacterial ...pans soiled by food inoculated with test bacteria were sampled for bacterial counts, cleaned and sanitized as previously reported (1). Inactivation of

  6. The wholesomeness of irradiated food

    International Nuclear Information System (INIS)

    Elias, P.S.; Matsuyama, A.

    1978-01-01

    It is apparent that there is a need for protection of the consumer and a need for governmental authorities to insure a safe and wholesome food supply for the population. Based on objective and scientific evidence regarding the safety of food irradiation, national and international health authorities are able to determine whether irradiated food is acceptable for human consumption. Following a thorough review of all available data, the Joint FAO/IAEA/WHO Expert Committee unconditionally approved wheat and ground wheat products and papaya irradiated for disingestation at a maximum dose of 100 krad, potatoes irradiated for sprout control at a maximum dose not exceeding 15 krad, and chicken irradiated at a maximum dose of 700 krad to reduce microbiological spoilage. Lastly, it unconditionally approved strawberries irradiated at a maximum dose of 300 krad to prolong storage. Onions at irradiated for sprout control at a maximum dose of 15 krad were temporarily approved, subject to preparation of further data on multigeneration reproduction studies on rats. Codfish and redfish eviscerated after irradiation at a maximum dose of 220 krad to reduce microbiological spoilage were also approved, based on the results of various studies in progress. Temporary, conditional approval of rice irradiated for insect disinfestation at a maximum dose of 100 krad was based on results of long-term studies on rats and monkies, available in the next review. Due to insufficient data, no decision regarding irradiated mushrooms was made. (Bell, E.)

  7. Role of radiation technology in preservation of food and agricultural commodities

    International Nuclear Information System (INIS)

    Rajput, Sanjay

    2016-01-01

    Several technological benefits can be achieved by gamma radiation processing of agricultural commodities and food include: inhibition of sprouting in tubers, bulbs and rhizomes; disinfestation of insect pests in stored products; disinfestation of quarantine pests in fresh produce; delay in ripening and senescence in fruits and vegetables; destruction of microbes responsible for spoilage of food; elimination of parasites and pathogens of public health importance in food

  8. Characterization of Bacteriophages Virulent for Clostridium perfringens and Identification of Phage Lytic Enzymes as Alternatives to Antibiotics for Potential Control of the Bacterium

    Science.gov (United States)

    Clostridium perfringens is a Gram-positive, spore-forming anaerobic bacterium that plays a significant role in human food-borne disease as well as non-food-borne human, animal, and poultry diseases. There has been a resurgent interest in the use of bacteriophages or their gene products to control b...

  9. Food irradiation - a viable technology for reducing postharvest losses of food

    International Nuclear Information System (INIS)

    Loaharanu, P.

    1985-01-01

    Research and development in the past 30 years have clearly demonstrated that food irradiation is a safe, effective and environmentally clean process of food preservation. Twenty-seven countries have approved over 40 irradiated foods or groups of related food items for human consumption, either on an unconditional or a restricted basis. The technology is beginning to play an important role in reducing post-harvest losses of food and in facilitating wider distribution of food in the trade. Its wide application in solving microbial spoilage losses of food, insect disinfestation, improving hygienic qualities, slowing down physiological processes of foods is reviewed. Special emphasis is placed on applications of direct relevance to countries in Asia and the Pacific region

  10. Influence of audiovisuals and food samples on consumer acceptance of food irradiation

    International Nuclear Information System (INIS)

    Pohlman, A.J.; Wood, O.B.; Mason, A.C.

    1994-01-01

    The effects of audiovisual presentation on consumers' knowledge and attitudes toward food irradiation were demonstrated. Food irradiation is a method of food preservation that can destroy the microorganisms responsible for many foodborne illnesses and food spoilage. However, the food industry has been slow to adopt this method because it is unsure of consumer acceptance. One hundred and seventy-nine consumers were given a slide-tape presentation on food irradiation. Test subjects were also presented with a sample of irradiated strawberries. It was found that participants knew more about and were more positive toward food irradiation following the educational program. These findings demonstrate the value of educational materials in influencing the food preferences of consumers

  11. Food irradiation - a viable technology for reducing post harvest losses of food

    International Nuclear Information System (INIS)

    Loaharanu, O.

    1985-01-01

    Research and development in the past 30 years have clearly demonstrated that food irradiation is a safe, effective and environmentally clean process of food preservation. Twenty-seven countries have approved over 40 irradiated foods or groups of related food items for human consumption, either on an unconditional or a restricted basis. The technology is beginning to play an important role in reducing post-harvest losses of food in facilitating wider distribution of food in the trade. Its wide application in solving microbial spoilage loss of food, insect disinfestation, improving hygenic qualities, slowing down physiological processes of foods is reviewed. Special emphasis is placed on applications of direct relevance to countries in Asia and the Pacific region. (author)

  12. Bacterial spores in food: how phenotypic variability complicates prediction of spore properties and bacterial behavior

    NARCIS (Netherlands)

    Eijlander, R.T.; Abee, T.; Kuipers, O.P.

    2011-01-01

    Bacillus spores are a known cause of food spoilage and their increased resistance poses a major challenge in efficient elimination. Recent studies on bacterial cultures at the single cell level have revealed how minor differences in essential spore properties, such as core water content or germinant

  13. Bacterial spores in food : how phenotypic variability complicates prediction of spore properties and bacterial behavior

    NARCIS (Netherlands)

    Eijlander, Robyn T.; Abee, Tjakko; Kuipers, Oscar P.

    Bacillus spores are a known cause of food spoilage and their increased resistance poses a major challenge in efficient elimination. Recent studies on bacterial cultures at the single cell level have revealed how minor differences in essential spore properties, such as core water content or germinant

  14. Potential use of Rosemary, Propolis and Thyme as Natural Food Preservatives

    NARCIS (Netherlands)

    Tzima, K.; Makris, D.; Nikiforidis, C.V.; Mourtzinos, I.

    2015-01-01

    The use of preservatives in food stuffs and beverages is essential in order to prevent spoilage due to microbial growth or undesirable chemical changes. However, the use of synthetic additives has been associated with various health problems. Therefore, consumers have turned suspicious and obverted

  15. Modified-atmosphere packaging of hen table eggs: effects on pathogen and spoilage bacteria.

    Science.gov (United States)

    Pasquali, F; Manfreda, G; Olivi, P; Rocculi, P; Sirri, F; Meluzzi, A

    2012-12-01

    As part of a more comprehensive research activity on the use of modified-atmosphere packaging for the improvement of quality and functional properties of table eggs, the effects of air, 100% CO(2), and 100% O(2) packaging were also evaluated on the survival of experimentally inoculated pathogen bacteria (Salmonella Enteritidis, Escherichia coli, and Listeria monocytogenes) as well as on spoilage bacteria (total aerobic mesophilic bacteria) on table eggs during 30 d of storage at 4, 25, and 37°C by colony count method. In general, temperatures played a major role, rather than gasses, in influencing the bacterial survival. In particular, the lowest microbial loads were registered at 4°C on E. coli and spoilage bacteria, whereas 37°C was the best storage temperature to avoid the psychrotropic microorganism L. monocytogenes development regardless of the gas used. One hundred percent CO(2) packaging, in association with a low storage temperature (4°C), had a significant positive effect in reducing Salmonella loads. On eggs inoculated with L. monocytogenes and stored at 4°C as well as on eggs containing only spoilage bacteria and stored at 25°C, 100% CO(2) resulted the best gas in comparison with air and O(2). One hundred percent CO(2) packaging showed no negative effect on pathogen survival compared with air. Although further improvements are required to control RH within packaging to limit bacteria growth/survival, in view of the positive effects of CO(2) packaging on quality traits of table eggs, 100% CO(2) packaging might represent a promising innovative technique for the maintenance of egg characteristics during transport, retail, and domestic storage.

  16. Characterization and evaluation of the spoilage potential of Lactococcus piscium isolates from modified atmosphere packaged meat.

    Science.gov (United States)

    Rahkila, Riitta; Nieminen, Timo; Johansson, Per; Säde, Elina; Björkroth, Johanna

    2012-05-01

    A total of 222 psychrotrophic lactococci isolated from use-by day, modified atmosphere packaged (MAP) meat were identified to the species level by numerical analyses of EcoRI and ClaI ribopatterns and phylogenetic sequence analyses of 16S, rpoA and pheS genes. In addition, their meat spoilage potential was studied. The majority of the isolates (n=215) were identified as Lactococcus piscium, while seven isolates belonged to Lactococcus raffinolactis. L. piscium was shown to be adapted to growing in a variety of MAP meat products including broiler, turkey, pork, and minced meat from beef and pork, where they belonged to the predominating microbiota at the end of the storage. Numerical analyses of EcoRI and ClaI ribopatterns, and phylogenetic sequence analyses of rpoA and pheS genes were shown to be reliable tools in species level identification of meat lactococci. The spoilage potential of L. piscium was evaluated by inoculating representative isolates to MAP pork stored at 6 °C for 22 days. Development of spoilage population was monitored using a culture-independent T-RFLP approach. The sensory shelf life of pork inoculated with L. piscium was shortened compared to the uninoculated control. Alongside with the inoculated L. piscium isolates, Leuconostoc spp. present as initial contaminants in the samples thrived. This shows that even though lactococci were inoculated at higher levels compared to the natural microbiota, they did not occupy the niche and prevent the growth of other lactic acid bacteria. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Role of plasmids in Lactobacillus brevis BSO 464 hop tolerance and beer spoilage.

    Science.gov (United States)

    Bergsveinson, Jordyn; Baecker, Nina; Pittet, Vanessa; Ziola, Barry

    2015-02-01

    Specific isolates of lactic acid bacteria (LAB) can grow in the harsh beer environment, thus posing a threat to brew quality and the economic success of breweries worldwide. Plasmid-localized genes, such as horA, horC, and hitA, have been suggested to confer hop tolerance, a trait required for LAB survival in beer. The presence and expression of these genes among LAB, however, do not universally correlate with the ability to grow in beer. Genome sequencing of the virulent beer spoilage organism Lactobacillus brevis BSO 464 revealed the presence of eight plasmids, with plasmids 1, 2, and 3 containing horA, horC, and hitA, respectively. To investigate the roles that these and the other five plasmids play in L. brevis BSO 464 growth in beer, plasmid curing with novobiocin was used to derive 10 plasmid variants. Multiplex PCRs were utilized to determine the presence or absence of each plasmid, and how plasmid loss affected hop tolerance and growth in degassed (noncarbonated) beer was assessed. Loss of three of the eight plasmids was found to affect hop tolerance and growth in beer. Loss of plasmid 2 (horC and 28 other genes) had the most dramatic effect, with loss of plasmid 4 (120 genes) and plasmid 8 (47 genes) having significant, but smaller, impacts. These results support the contention that genes on mobile genetic elements are essential for bacterial growth in beer and that beer spoilage ability is not dependent solely on the three previously described hop tolerance genes or on the chromosome of a beer spoilage LAB isolate.

  18. Antimicrobial assays of natural extracts and their inhibitory effect against Listeria innocua and fish spoilage bacteria, after incorporation into biopolymer edible films.

    Science.gov (United States)

    Iturriaga, L; Olabarrieta, I; de Marañón, I Martínez

    2012-08-01

    The antimicrobial activity of twelve natural extracts was tested against two fish spoilage bacteria (Pseudomonas fluorescens and Aeromonas hydrophila/caviae) and Listeria innocua, in order to assess their potential utilization in the preservation and safety of minimally processed fish products. After a screening of the active extracts by agar diffusion and vapour diffusion methods, oregano and thyme essential oils and citrus extract were selected. The minimum inhibitory concentration (MIC) of the selected extracts was determined by disc diffusion method against target bacteria and at two temperatures: bacteria's optimal growth temperature (30 °C or 37 °C) and refrigeration temperature (4 °C). Due to its better solubility, lack of odour and greater inhibitory effect obtained against L. innocua at refrigerated temperature, citrus extract was selected and incorporated at 1% (v/v) into different biopolymer film forming solutions (gelatin, methyl cellulose and their blend 50:50 w/w). The antimicrobial activity of the developed films was then evaluated, just after preparation of the films and after one month of storage at 43±3% relative humidity and 24±3 °C. Regardless of the biopolymer matrix, all the developed films showed antimicrobial activity against the target bacteria. The most sensitive bacterium towards active films was L. innocua while P. fluorescens appeared as the most resistant one, in accordance with the previously performed antimicrobial tests for pure extracts. The differences in activity of the films between the tested two temperatures were not significant except for L. innocua, for which three times higher inhibition diameters were observed at refrigerated temperature. The inhibitory effectiveness of the films against the tested strains was maintained regardless of the biopolymer matrix for at least one month. Therefore, these edible films show potential for their future use in fresh fish fillets preservation. Copyright © 2012 Elsevier B.V. All

  19. The use of chitooligosaccharide in beer brewing for protection against beer-spoilage bacteria and its influence on beer performance.

    Science.gov (United States)

    Zhao, Xue; Yu, Zhimin; Wang, Ting; Guo, Xuan; Luan, Jing; Sun, Yumei; Li, Xianzhen

    2016-04-01

    To identify a biological preservative that can protect beer from microbial contamination, which often results in the production of turbidity and off-flavor. The antimicrobial activity of a chitooligosaccharide against beer-spoilage bacteria and its effect on the fermentation performance of brewer's yeast was studied. Chitooligosaccharide with an average 2 kDa molecular weight was the best at inhibiting all tested beer-spoilage bacteria. The application of chitooligosaccharide in the brewing process did not influence the fermentation of brewer's yeast. The change in beer performance induced by the contamination of Lactobacillus brevis could be effectively controlled by application of chitooligosaccharide in the beer brewing process. The experimental data suggested that chitooligosaccharide should be an excellent preservative to inhibit beer-spoilage bacteria in the brewing process and in the end product.

  20. Bacterium-like Particles for efficient immune stimulation of existing vaccines and new subunit vaccines in mucosal applications

    Directory of Open Access Journals (Sweden)

    Natalija eVan Braeckel-Budimir

    2013-09-01

    Full Text Available The successful development of a mucosal vaccine critically depends on the use of a safe and effective immunostimulant and/or carrier system. This review describes the effectiveness and mode of action of an immunostimulating particle derived from bacteria in mucosal subunit vaccines. The non-living particles, designated Bacterium-like Particles (BLPs are based on the food-grade bacterium Lactococcus lactis. The focus of the overview is on the development of intranasal BLP-based vaccines to prevent diseases caused by influenza and respiratory syncytial virus, and includes a selection of Phase I clinical data for the intranasal FluGEM vaccine.

  1. The involvement of bacterial quorum sensing in the spoilage of refrigerated Litopenaeus vannamei.

    Science.gov (United States)

    Zhu, Suqin; Wu, Haohao; Zeng, Mingyong; Liu, Zunying; Wang, Ying

    2015-01-02

    Quorum-sensing signals in refrigerated shrimp (Litopenaeus vannamei) undergoing spoilage were examined using bioreporter assays, thin-layer chromatography and gas chromatography-mass spectrometry, and the results revealed the presence of three types of autoinducers including acetylated homoserine lactones (AHLs) (i.e., N-hexanoyl-homoserine lactone, N-oxohexanoyl-homoserine lactone and N-octanoyl-homoserine lactone), autoinducer-2, and cyclic dipeptides (i.e., cyclo-(L-Pro-L-Leu), cyclo-(L-Leu-L-Leu) and cyclo-(L-Pro-L-Phe)). Autoinducer-2, rather than any AHL, was detected in extracts from pure cultures of the specific spoilage organisms (SSO), i.e., Shewanella putrefaciens (SS01) and Shewanella baltica (SA02). As for the cyclic peptides, only SA02 was determined to produce cyclo-(L-Pro-L-Leu). According to the transcription levels of LuxR (the master quorum-sensing regulator) in the SSO in response to exogenous autoinducers, the SSO could sense AHLs and cyclo-(L-Leu-L-Leu), rather than autoinducer-2, cyclo-(L-Leu-L-Leu) and cyclo-(L-Pro-L-Phe). In accordance with the results of LuxR expression, the production of biofilm matrixes and extracellular proteases in the SSO was regulated by exogenous AHLs and cyclo-(L-Pro-L-Leu), rather than 4,5-dihydroxy-2,3-pentanedione (the autoinducer-2 precursor), cyclo-(L-Leu-L-Leu) and cyclo-(L-Pro-L-Phe). Exogenous N-hexanoyl-homoserine lactone and cyclo-(L-Pro-L-Leu) increased the growth rates and population percentages of the SSO in shrimp samples under refrigerated storage, and interestingly, exogenous 4,5-dihydroxy-2,3-pentanedione also increased the population percentages of the SSO in vivo by inhibiting the growth of the competing bacteria. However, according to the levels of TVB-N and the volatile organic components in the shrimp samples, exogenous 4,5-dihydroxy-2,3-pentanedione did not accelerate the shrimp spoilage process as N-hexanoyl-homoserine lactone and cyclo-(L-Pro-L-Leu) did. In summary, our results suggest that

  2. The spoilage yeast Zygosaccharomyces bailii forms mitotic spores: a screening method for haploidization.

    Science.gov (United States)

    Rodrigues, Fernando; Ludovico, Paula; Sousa, Maria João; Steensma, H Yde; Côrte-Real, Manuela; Leão, Cecília

    2003-01-01

    Zygosaccharomyces bailii ISA 1307 and the type strain of this spoilage yeast show a diploid DNA content. Together with a rather peculiar life cycle in which mitotic but no meiotic spores appear to be formed, the diploid DNA content explains the observed difficulties in obtaining auxotrophic mutants. Mitotic chromosome loss induced by benomyl and selection on canavanine media resulted in three haploid strains of Z. bailii. This new set of Z. bailii strains allows the easy isolation of recessive mutants and is suitable for further molecular genetic studies.

  3. Role of Plasmids in Lactobacillus brevis BSO 464 Hop Tolerance and Beer Spoilage

    OpenAIRE

    Bergsveinson, Jordyn; Baecker, Nina; Pittet, Vanessa; Ziola, Barry

    2014-01-01

    Specific isolates of lactic acid bacteria (LAB) can grow in the harsh beer environment, thus posing a threat to brew quality and the economic success of breweries worldwide. Plasmid-localized genes, such as horA, horC, and hitA, have been suggested to confer hop tolerance, a trait required for LAB survival in beer. The presence and expression of these genes among LAB, however, do not universally correlate with the ability to grow in beer. Genome sequencing of the virulent beer spoilage organi...

  4. The influence of substrate on siderophore production by fish spoilage bacteria

    DEFF Research Database (Denmark)

    Gram, Lone

    1996-01-01

    Siderophore production of fish spoilage bacteria (5 isolates of Shewanella putrefaciens and 5 of Pseudomonas sp.) was determined in fish extract, Tris-succinate medium, a liquid medium of the Chrome-Azurol-S (CAS) agar and in M9 medium supplemented with glucose and casamino acids (M9GC). One...... isolates. S. putrefaciens produced siderophores of the hydroxamate type in fish extract and to a lesser extend in the M9GC medium. Growth was supported by the other media. S. putrefaciens grew weakly on the Chrome-azurol-S (CAS agar as this medium did not support siderophore-production. However...

  5. Combination treatment of gamma radiation and paraben in controlling spoilage of poultry meat

    International Nuclear Information System (INIS)

    Shiralkar, N.D.; Rege, D.V.

    1977-01-01

    With a view of controlling spoilage, combination treatment of poultry meat with gamma radiation and a chemical preservative has been investigated. Raw poultry pieces of about 25 g. weight were dipped in 0.1% propyl-paraben solution for two hours and were given a 0.1 Mrad dose from 60 Co gamma radiation. It was found that paraben was not affected by irradiation. The flavour evaluation scores indicated the shelf-life of poultry meat was prolonged by a couple of days as compared to untreated controls in refrigerated storage. (M.G.B.)

  6. Challenges and advances in systems biology analysis of Bacillus spore physiology; molecular differences between an extreme heat resistant spore forming Bacillus subtilis food isolate and a laboratory strain

    NARCIS (Netherlands)

    Brul, Stanley; van Beilen, Johan; Caspers, Martien P M; O'Brien, Andrea; de Koster, Chris; Oomes, Suus; Smelt, Jan; Kort, Remco; Ter Beek, Alex

    Bacterial spore formers are prime organisms of concern in the food industry. Spores from the genus Bacillus are extremely stress resistant, most notably exemplified by high thermotolerance. This sometimes allows surviving spores to germinate and grow out to vegetative cells causing food spoilage and

  7. Challenges and advances in systems biology analysis of Bacillus spore physiology; molecular differences between an extreme heat resistant spore forming Bacillus subtilis food isolate and a laboratory strain

    NARCIS (Netherlands)

    Brul, S.; van Beilen, J.; Caspers, M.; O'Brien, A.; de Koster, C.; Oomes, S.; Smelt, J.; Kort, R.; ter Beek, A.

    2011-01-01

    Bacterial spore formers are prime organisms of concern in the food industry. Spores from the genus Bacillus are extremely stress resistant, most notably exemplified by high thermotolerance. This sometimes allows surviving spores to germinate and grow out to vegetative cells causing food spoilage and

  8. An Overview on the Effects of Sodium Benzoate as a Preservative in Food Products

    Directory of Open Access Journals (Sweden)

    Shahmohammadi

    2016-05-01

    Full Text Available Context Food spoilage has been a common problem throughout history, and much of the spoilage is caused the activity of microorganisms or enzymatic reactions during the storage of food. Thus, using chemical substances could prevent or delay food spoilage and this has led to the great success of these compounds in the treatment of human diseases. Sodium benzoate is one of the synthetic additives that are widely used in the food industry. Evidence Acquisition In this review we summarized the history and role of benzoate sodium in the food industry, its limited value in different food, other uses, pharmacokinetics, and its toxicity in animal studies. A literature search was carried out using MEDLINE, Scopus, Science Direct, and Scientific Information Databases (SID. Results Sodium benzoate is used in different industries as well as the food industry and it has adverse effects similar to other food additives. Conclusions Studies on natural ingredients in foods to find compounds with similar effects as benzoate with less adverse effects is necessary.

  9. Antifungal Microbial Agents for Food Biopreservation-A Review.

    Science.gov (United States)

    Leyva Salas, Marcia; Mounier, Jérôme; Valence, Florence; Coton, Monika; Thierry, Anne; Coton, Emmanuel

    2017-07-08

    Food spoilage is a major issue for the food industry, leading to food waste, substantial economic losses for manufacturers and consumers, and a negative impact on brand names. Among causes, fungal contamination can be encountered at various stages of the food chain (e.g., post-harvest, during processing or storage). Fungal development leads to food sensory defects varying from visual deterioration to noticeable odor, flavor, or texture changes but can also have negative health impacts via mycotoxin production by some molds. In order to avoid microbial spoilage and thus extend product shelf life, different treatments-including fungicides and chemical preservatives-are used. In parallel, public authorities encourage the food industry to limit the use of these chemical compounds and develop natural methods for food preservation. This is accompanied by a strong societal demand for 'clean label' food products, as consumers are looking for more natural, less severely processed and safer products. In this context, microbial agents corresponding to bioprotective cultures, fermentates, culture-free supernatant or purified molecules, exhibiting antifungal activities represent a growing interest as an alternative to chemical preservation. This review presents the main fungal spoilers encountered in food products, the antifungal microorganisms tested for food bioprotection, and their mechanisms of action. A focus is made in particular on the recent in situ studies and the constraints associated with the use of antifungal microbial agents for food biopreservation.

  10. ENHANCING FOOD SAFETY AND STABILITY THROUGH IRRADIATION: A REVIEW

    Directory of Open Access Journals (Sweden)

    Manzoor Ahmad Shah

    2014-04-01

    Full Text Available Food irradiation is one of the non thermal food processing methods. It is the process of exposing food materials to the controlled amounts of ionizing radiations such as gamma rays, X-rays and accelerated electrons, to improve microbiological safety and stability. Irradiation disrupts the biological processes that lead to decay of food quality. It is an effective tool to reduce food-borne pathogens, spoilage microorganisms and parasites; to extend shelf-life and for insect disinfection. The safety and consumption of irradiated foods have been extensively studied at national levels and in international cooperations and have concluded that foods irradiated under appropriate technologies are both safe and nutritionally adequate. Specific applications of food irradiation have been approved by national legislations of more than 55 countries worldwide. This review aims to discuss the applications of irradiation in food processing with the emphasis on food safety and stability.

  11. Promotion of food irradiation in Japan

    International Nuclear Information System (INIS)

    Kondo, Shunsuke; Tanaka, Shunichi; Tada, Mikitaro; Furuta, Masakazu; Kume, Tamikazu; Hayashi, Toru; Yamamoto, Kazuko

    2007-01-01

    Atomic Energy Commission of Japan has organized special symposia inviting citizens and consumers on food irradiation based on the report presented by expert members meeting discussing about food irradiation in various countries as well as in Japan. This document summarizes the lectures and talks presented at the symposia: usefulness of food irradiation, one of the most effective means of sterilization to ensure sanitary supplies and to prevent loss from spoilage, activities of the subcommittee consisting of experts of this field, a report of the open forum with public participants on food irradiation, present status of detection techniques for the irradiated foods, the role of phyto-sanitary measures in plant protection, and how to realize the consumer's free choices for irradiated foods. (S. Ohno)

  12. Testing commercial biopreservative against spoilage microorganisms in MAP packed Ricotta fresca cheese.

    Science.gov (United States)

    Spanu, C; Scarano, C; Piras, F; Spanu, V; Pala, C; Casti, D; Lamon, S; Cossu, F; Ibba, M; Nieddu, G; De Santis, E P L

    2017-09-01

    Ricotta fresca cheese is susceptible to secondary contamination and is able to support the growth of pathogens or spoilage psychotrophic bacteria during storage. The aim of the present study was to evaluate which among three commercial biopreservatives was suitable to be used to control the growth of spoilage microorganisms in sheep's milk MAP ricotta fresca cheese. 144 Ricotta fresca cheese samples were inoculated either with the bioprotective culture Lyofast FPR 2 (including Enterococcus faecium, Lactobacillus plantarum e Lactobacillus rhamnosus) or Lyofast CNBAL (Carnobacterium spp) or the fermentate MicroGARD 430. Not inoculated control and experimental ricotta were MAP packed (30% CO 2 and 70% N 2 ) and stored at 4 °C. Triplicate samples were analyzed after 5 h and 7, 14 and 21 days after inoculation for total bacterial count, mesophilic lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp, Listeria monocytogenes, moulds and yeasts. Among the tested biopreservatives only Carnobacterium spp was able to control Pseudomonas spp and Enterobacteriaceae. The maximum reduction in the concentration of Pseudomonas spp and Enterobacteriaceae was respectively 1.93 and 2.66 log 10  cfu/g, observed 14 days after production. Therefore, Carnobacterium spp was selected as the culture of choice to conduct a challenge study against Pseudomonas spp. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Characterization of spoilage bacteria in pork sausage by PCR-DGGE analysis

    Directory of Open Access Journals (Sweden)

    Francesca Silva Dias

    2013-09-01

    Full Text Available To investigate microbial diversity and identify spoilage bacteria in fresh pork sausages during storage, twelve industrial pork sausages of different trademarks were stored at 4 ºC for 0, 14, 28 and 42 days, 80% relative humidity and packaged in sterile plastic bags. Microbiological analysis was performed. The pH and water activity (a w were measured. The culture-independent method performed was the Polymerase Chain Reaction - Denaturing Gradient Gel Electrophoresis (PCR-DGGE. The culture-dependent method showed that the populations of mesophilic bacteria and Lactic Acid Bacteria (LAB increased linearly over storage time. At the end of the storage time, the average population of microorganisms was detected, in general, at the level of 5 log cfu g-1. A significant (P < 0.005 increase was observed in pH and a w values at the end of the storage time. The PCR-DGGE allowed a rapid identification of dominant communities present in sausages. PCR-DGGE discriminated 15 species and seven genera of bacteria that frequently constitute the microbiota in sausage products. The most frequent spoilage bacteria identified in the sausages were Lactobacillus sakei and Brochothrix thermosphacta. The identification of dominant communities present in fresh pork sausages can help in the choice of the most effective preservation method for extending the product shelf-life.

  14. American Lobsters (Homarus Americanus) not Surviving During Air Transport: Evaluation of Microbial Spoilage.

    Science.gov (United States)

    Tirloni, Erica; Stella, Simone; Gennari, Mario; Colombo, Fabio; Bernardi, Cristian

    2016-04-19

    Eighteen American lobsters ( Homarus americanus ), dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters' meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these not-surviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1%) and Photobacterium spp. (24.1%), and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3%) and lipolytic ability (75.5%), suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

  15. American lobsters (Homarus americanus not surviving during air transport: evaluation of microbial spoilage

    Directory of Open Access Journals (Sweden)

    Erica Tirloni

    2016-05-01

    Full Text Available Eighteen American lobsters (Homarus americanus, dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters’ meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these notsurviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1% and Photobacterium spp. (24.1%, and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3% and lipolytic ability (75.5%, suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

  16. Risk assessment of fungal spoilage: A case study of Aspergillus niger on yogurt.

    Science.gov (United States)

    Gougouli, Maria; Koutsoumanis, Konstantinos P

    2017-08-01

    A quantitative risk assessment model of yogurt spoilage by Aspergillus niger was developed based on a stochastic modeling approach for mycelium growth by taking into account the important sources of variability such as time-temperature conditions during the different stages of chill chain and individual spore behavior. Input parameters were fitted to the appropriate distributions and A. niger colony's diameter at each stage of the chill chain was estimated using Monte Carlo simulation. By combining the output of the growth model with the fungus prevalence, that can be estimated by the industry using challenge tests, the risk of spoilage translated to number of yogurt cups in which a visible mycelium of A. niger is being formed at the time of consumption was assessed. The risk assessment output showed that for a batch of 100,000 cups in which the percentage of contaminated cups with A. niger was 1% the predicted numbers (median (5 th , 95 th percentiles)) of the cups with a visible mycelium at consumption time were 8 (5, 14). For higher percentages of 3, 5 and 10 the predicted numbers (median (5 th , 95 th percentiles)) of the spoiled cups at consumption time were estimated to be 24 (16, 35), 39 (29, 52) and 80 (64, 94), respectively. The developed model can lead to a more effective risk-based quality management of yogurt and support the decision making in yogurt production. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Farm and abattoir sources of Carnobacterium species and implications for lamb meat spoilage.

    Science.gov (United States)

    Mills, John; Horváth, Kylie Marree; Reynolds, Angela Denise; Brightwell, Gale

    2018-03-01

    To investigate the transmission route of Carnobacterium from the farm environment to the meat-manufacturing plant and potential risk for meat spoilage. A sheep farm level survey of Carnobacterium, consisting of 150 environmental and animal (no 100) associated samples, was carried out on two farms. A further 20 lamb carcass samples were taken from an abattoir servicing one of the farms. The majority of C. maltaromaticum isolates were associated with fleece followed by hard sheep contact surfaces, rectal-anal-mucosal swabs and carcasses. Enterobacterial Repetitive Intergenic Consenus PCR (ERIC-PCR) profiling revealed 4 distinct ERIC types. Each ERIC type was found on both farms, three of which were also found on lamb carcasses. ERIC-PCR was effective at demonstrating within-species variability of C. maltaromaticum. This study provides initial information showing that farm sources maybe an important transmission route of Carnobacterium for contamination of lamb carcasses and subsequently the meat processing environment. Data on distribution, diversity, sources and transmission routes for meat product contamination is limited for spoilage bacteria. This study highlights the importance of good hygienic slaughter practices and cleaning routines to remove accumulated detritus from the handling of animals that may lead to cross contamination. This article is protected by copyright. All rights reserved.

  18. Adaptive response and tolerance to sugar and salt stress in the food yeast Zygosaccharomyces rouxii.

    Science.gov (United States)

    Dakal, Tikam Chand; Solieri, Lisa; Giudici, Paolo

    2014-08-18

    The osmotolerant and halotolerant food yeast Zygosaccharomyces rouxii is known for its ability to grow and survive in the face of stress caused by high concentrations of non-ionic (sugars and polyols) and ionic (mainly Na(+) cations) solutes. This ability determines the success of fermentation on high osmolarity food matrices and leads to spoilage of high sugar and high salt foods. The knowledge about the genes, the metabolic pathways, and the regulatory circuits shaping the Z. rouxii sugar and salt-tolerance, is a prerequisite to develop effective strategies for fermentation control, optimization of food starter culture, and prevention of food spoilage. This review summarizes recent insights on the mechanisms used by Z. rouxii and other osmo and halotolerant food yeasts to endure salts and sugars stresses. Using the information gathered from S. cerevisiae as guide, we highlight how these non-conventional yeasts integrate general and osmoticum-specific adaptive responses under sugar and salts stresses, including regulation of Na(+) and K(+)-fluxes across the plasma membrane, modulation of cell wall properties, compatible osmolyte production and accumulation, and stress signalling pathways. We suggest how an integrated and system-based knowledge on these mechanisms may impact food and biotechnological industries, by improving the yeast spoilage control in food, enhancing the yeast-based bioprocess yields, and engineering the osmotolerance in other organisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Nanotechnology for Food Packaging and Food Quality Assessment.

    Science.gov (United States)

    Rossi, Marco; Passeri, Daniele; Sinibaldi, Alberto; Angjellari, Mariglen; Tamburri, Emanuela; Sorbo, Angela; Carata, Elisabetta; Dini, Luciana

    Nanotechnology has paved the way to innovative food packaging materials and analytical methods to provide the consumers with healthier food and to reduce the ecological footprint of the whole food chain. Combining antimicrobial and antifouling properties, thermal and mechanical protection, oxygen and moisture barrier, as well as to verify the actual quality of food, e.g., sensors to detect spoilage, bacterial growth, and to monitor incorrect storage conditions, or anticounterfeiting devices in food packages may extend the products shelf life and ensure higher quality of foods. Also the ecological footprint of food chain can be reduced by developing new completely recyclable and/or biodegradable packages from natural and eco-friendly resources. The contribution of nanotechnologies to these goals is reviewed in this chapter, together with a description of portable devices ("lab-on-chip," sensors, nanobalances, etc.) which can be used to assess the quality of food and an overview of regulations in force on food contact materials. © 2017 Elsevier Inc. All rights reserved.

  20. Food irradiation: a look at regulatory status, consumer acceptance, and economies of scale

    International Nuclear Information System (INIS)

    Morrison, R.M.

    1986-01-01

    Food irradiation is receiving renewed attention by many individuals--scientists, policy makers, agricultural producers, public health officials, and consumers. Interest in food irradiation’s benefits and limitations has been piqued by recent concerns over the safety of chemical fumigants and preservatives and interest in reducing the incidence of food borne diseases. Individuals concerned with food shortage problems in developing countries are anxious to see if irradiation can be used to eliminate high spoilage losses in those countries. Food processors and retailers are always looking for less costly preservation methods and exploring new techniques to achieve desirable qualities in fresh and processed foods

  1. Bacteriophage GC1, a Novel Tectivirus Infecting Gluconobacter Cerinus, an Acetic Acid Bacterium Associated with Wine-Making.

    Science.gov (United States)

    Philippe, Cécile; Krupovic, Mart; Jaomanjaka, Fety; Claisse, Olivier; Petrel, Melina; le Marrec, Claire

    2018-01-16

    The Gluconobacter phage GC1 is a novel member of the Tectiviridae family isolated from a juice sample collected during dry white wine making. The bacteriophage infects Gluconobacter cerinus , an acetic acid bacterium which represents a spoilage microorganism during wine making, mainly because it is able to produce ethyl alcohol and transform it into acetic acid. Transmission electron microscopy revealed tail-less icosahedral particles with a diameter of ~78 nm. The linear double-stranded DNA genome of GC1 (16,523 base pairs) contains terminal inverted repeats and carries 36 open reading frames, only a handful of which could be functionally annotated. These encode for the key proteins involved in DNA replication (protein-primed family B DNA polymerase) as well as in virion structure and assembly (major capsid protein, genome packaging ATPase (adenosine triphosphatase) and several minor capsid proteins). GC1 is the first tectivirus infecting an alphaproteobacterial host and is thus far the only temperate tectivirus of gram-negative bacteria. Based on distinctive sequence and life-style features, we propose that GC1 represents a new genus within the Tectiviridae , which we tentatively named " Gammatectivirus ". Furthermore, GC1 helps to bridge the gap in the sequence space between alphatectiviruses and betatectiviruses.

  2. Comparison of some physical techniques for detection of spoilage in apple juice inoculated with Saccharomyces cerevisiae: Optical and photothermal methods

    NARCIS (Netherlands)

    Chirtoc, I.; Chirtoc, M.; Bicanic, D.D.; Cozijnsen, J.L.; Breeuwer, P.

    2003-01-01

    Several physical techniques were used to study the extent of spoilage in apple juice deliberately inoculated with yeast (concentration of Saccharomyces cerevisiae ranged from 25 cells mL(-1) to 2.5 x 10(6) cells mL(-1), respectively) and their performance compared in terms of detection limit

  3. Modelling and predicting the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon

    DEFF Research Database (Denmark)

    Gimenez, B.; Dalgaard, Paw

    2004-01-01

    Aims: To evaluate and model the simultaneous growth of Listeria monocytogenes and spoilage micro-organisms in cold-smoked salmon.Methods and Results: Growth kinetics of L. monocytogenes, lactic acid bacteria (LAB), Enterobacteriaceae, enterococci and Photobacterium phosphoreum were determined in ...

  4. Predictive microbiology combined with metagenomic analysis targeted on the 16S rDNA : A new approach for food quality

    OpenAIRE

    Delhalle, Laurent; Taminiau, Bernard; Ellouze, Mariem; Nezer, Carine; Daube, Georges

    2013-01-01

    OBJECTIVES The food spoilage process is mainly caused by alteration micro-organisms and classical culture-based methods have therefore been used to assess the microbiological quality of food. These techniques are simple to implement but may not be relevant to understand the modifications of the microbial ecology which occur in the food product in response to different changes in the environmental conditions. Metagenomic analysis targeted on 16S ribosomal DNA can bring about a solution to t...

  5. Evaluation of spoilage potential and volatile metabolites production by Shewanella baltica isolated from modified atmosphere packaged live mussels.

    Science.gov (United States)

    Odeyemi, Olumide A; Burke, Christopher M; Bolch, Christopher J S; Stanley, Roger

    2018-01-01

    Under the current commercial practice, live mussels only have 10days' shelf-life. Observed spoilage indices reduce consumers' acceptance, palatability and shelf-life of modified atmosphere packaged (MAP) live mussels. The aims of this study are to isolate specific spoilage bacteria from modified atmosphere packaged live mussels, evaluate isolates for microbial spoilage indices using qualitative methods and volatile metabolites production. Forty-six hydrogen sulphide producing bacteria were isolated and evaluated for trimethylamine n-oxide (TMAO) reduction, proteolytic and lipolytic activities and hydrogen sulphide production. Twenty-eight isolates were obtained from pouch water and 18 from mussel meat. All the isolates could produce H 2 S on Iron agar at 25°C while 30/46 produced H 2 S at 4°C and tolerate 0-6% NaCl. Four (4/46) isolates could not hydrolyse mussel protein. Over 80% isolates reduced TMAO to TMA in 3days with the production of H 2 S. Results of this study shows hydrogen sulphide producing bacteria isolated from MAP live mussels produce microbial spoilage indices. Isolate with highest enzymatic activities and hydrogen sulphide production was identified as Shewanella baltica using 16S rRNA gene. Axenic culture of the isolate was inoculated into sterile mussel broth. Inoculated sample was further stored at 4°C for 10days for spoilage study. Volatile metabolites produced during storage were evaluated using headspace solid phase micro-extraction gas chromatography mass spectrometry (HS-SPME GC/MS). A total of 44 compounds were identified in the sample after 10days while 27 compounds were identified in inoculated mussel broth. Group of compounds identified are alcohols, aldehydes, phenol, furans, ketone, esters, organic acid, aromatic hydrocarbons, alkanes, nitrogen and sulphur containing compounds. Dimethyl trisulphide, methyl-phenol, 3,5-octadiene and thiohexene were unique to inoculated mussel broth. Understanding spoilage mechanism and attendant

  6. Gracilibacillus kimchii sp. nov., a halophilic bacterium isolated from kimchi.

    Science.gov (United States)

    Oh, Young Joon; Lee, Hae-Won; Lim, Seul Ki; Kwon, Min-Sung; Lee, Jieun; Jang, Ja-Young; Park, Hae Woong; Nam, Young-Do; Seo, Myung-Ji; Choi, Hak-Jong

    2016-09-01

    A novel halophilic bacterium, strain K7(T), was isolated from kimchi, a traditional Korean fermented food. The strain is Gram-positive, motile, and produces terminal endospores. The isolate is facultative aerobic and grows at salinities of 0.0-25.0% (w/v) NaCl (optimum 10-15% NaCl), pH 5.5-8.5 (optimum pH 7.0-7.5), and 15-42°C (optimum 37°C). The predominant isoprenoid quinone in the strain is menaquinone-7 and the peptidoglycan of the strain is meso-diaminopimelic acid. The major fatty acids of the strain are anteisio-C15:0, iso-C15:0, and, C16:0 (other components were < 10.0%), while the major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, and three unidentified lipids. A phylogenetic analysis of 16S rRNA gene sequence similarity showed that the isolated strain was a cluster of the genus Gracilibacillus. High levels of gene sequence similarity were observed between strain K7(T) and Gracilibacillus orientalis XH-63(T) (96.5%), and between the present strain and Gracilibacillus xinjiangensis (96.5%). The DNA G+C content of this strain is 37.7 mol%. Based on these findings, strain K7(T) is proposed as a novel species: Gracilibacillus kimchii sp. nov. The type strain is K7(T) (KACC 18669(T); JCM 31344(T)).

  7. Agrobacterium tumefaciens is a diazotrophic bacterium

    International Nuclear Information System (INIS)

    Kanvinde, L.; Sastry, G.R.K.

    1990-01-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grown on nitrogen-free medium, reduce acetylene to ethylene, and incorporate 15 N supplied as 15 N 2 . As with most other well-characterized diazotrophic bacteria, the presence of NH 4 + in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship

  8. Functions of Nano-Materials in Food Packaging

    Science.gov (United States)

    Yap, Ray Chin Chong; Kwablah, Amegadze Paul Seyram; He, Jiating; Li, Xu

    Food packaging has been changing from bulky and rigid form in the past to different variation of lights and plastic packagings. Regardless of the changes, the packaging must be able to uphold its original function which is to serve as food containment as well as to protect the food from the external environment. Coupled with the increasing consumer’s awareness on food waste, higher standard of living, technological developments are underway to enhance the shelf-life of packed food as well as methods to provide indications of food packaging environment. There are many different indicators for food spoilage, but two commonly found gases in food packaging are oxygen and carbon dioxide. Oxygen is the main mechanism for food spoilage, while carbon dioxide is often used in modified-atmosphere-packaging. There are also different methods of gas scavenging and/or sensing techniques based on different concepts in the literature. In this review, the focus will be on nano-materials, namely titanium dioxide, silica, zeolites and metal organic frameworks. This review is structured in a manner to highlight how each material can be used in both gas scavenging and/or indicators applications. The last part of the review focuses on the approach and some key considerations when integrating nano-materials into the plastic film.

  9. Mesophilic and psychrotrophic bacteria from meat and their spoilage potential in vitro and in beef.

    Science.gov (United States)

    Ercolini, Danilo; Russo, Federica; Nasi, Antonella; Ferranti, Pasquale; Villani, Francesco

    2009-04-01

    Mesophilic and psychrotrophic populations from refrigerated meat were identified in this study, and the spoilage potential of microbial isolates in packaged beef was evaluated by analyzing the release of volatile organic compounds (VOC) by gas chromatography-mass spectrometry (GC/MS). Fifty mesophilic and twenty-nine psychrotrophic isolates were analyzed by random amplified polymorphic DNA-PCR, and representative strains were identified by 16S rRNA gene sequencing. Carnobacterium maltaromaticum and C. divergens were the species most frequently found in both mesophilic and psychrotrophic populations. Acinetobacter baumannii, Buttiauxella spp. and Serratia spp. were identified among the mesophilic isolates, while Pseudomonas spp. were commonly identified among the psychrotrophs. The isolates were further characterized for their growth at different temperatures and their proteolytic activity in vitro on meat proteins extracts at 7 degrees C. Selected proteolytic strains of Serratia proteamaculans, Pseudomonas fragi, and C. maltaromaticum were used to examine their spoilage potential in situ. Single strains of these species and mixtures of these strains were used to contaminate beef chops that were packed and stored at 7 degrees C. At time intervals up to 1 month, viable counts were determined, and VOC were identified by GC/MS. Generally, the VOC concentrations went to increase during the storage of the contaminated meats, and the profiles of the analyzed meat changed dramatically depending on the contaminating microbial species. About 100 volatiles were identified in the different contaminated samples. Among the detected volatiles, some specific molecules were identified only when the meat was contaminated by a specific microbial species. Compounds such as 2-ethyl-1-hexanol, 2-buten-1-ol, 2-hexyl-1-octanol, 2-nonanone, and 2-ethylhexanal were detectable only for C. maltaromaticum, which also produced the highest number of aldehydes, lactones, and sulfur compounds. The

  10. Food irradiation: an alternative technology

    International Nuclear Information System (INIS)

    Loaharanu, P.

    1985-01-01

    History has shown that man has continued to search for methods to protect his food from various spoilage agents. Traditional methods of food preservation such as drying, salting, fermentation, have been known for centuries and are being practised even today. Within the past century, modern technologies such as canning, freezing, refrigeration, the use of preservatives and pesticides, have further equipped man with an arsenal of methods to combat food losses and to increase the quantity, quality and safety of our food supplies. The most recent technology, irradiation, has gone through a great deal of research and development in the past 40 years and has shown a strong potential as another method for food preservation. As irradiation is still not familiar to the public at large, this paper attempts to inform scientists, officials, representatives of the food industry, and consumers of the global situation of the safety, benefits and applications of food irradiation by answering common questions often asked about the technology today. Special emphasis will be placed on the possible contribution of food irradiation to ASEAN

  11. Microbial spoilage and formation of biogenic amines in fresh and thawed modified atmosphere-packed salmon ( Salmo salar ) at 2 degrees C

    DEFF Research Database (Denmark)

    Emborg, Jette; Laursen, B.G.; Rathjen, T.

    2002-01-01

    Aims: To evaluate the microbial spoilage, formation of biogenic amines and shelf life of chilled fresh and frozen/thawed salmon packed in a modified atmosphere and stored at 2 degrees C.Methods and Results: The dominating microflora, formation of biogenic amines and shelf life were studied in two...... series of storage trials with naturally contaminated fresh and thawed modified atmosphere-packed (MAP) salmon at 2 degrees C. Photobacterium phosphoreum dominated the spoilage microflora of fresh MAP salmon at more than 106 cfu g-1 and the activity of this specific spoilage organism (SSO) limited...

  12. Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon ( Salmo salar ) analyzed by GC-MS and multivariate regression

    DEFF Research Database (Denmark)

    Jørgensen, Lasse Vigel; Huss, Hans Henrik; Dalgaard, Paw

    2001-01-01

    -carboxaldehyde produced by autolytic activity. Only a few of the volatile compounds produced during spoilage of cold-smoked salmon had an aroma value high enough to indicate contribution to the spoilage off- flavor of cold-smoked salmon. These were trimethylamine, 3- methylbutanal, 2-methyl-1-butanol, 3-methyl-1-butanol......, 1- penten-3-ol, and 1-propanol. The potency and importance of these compounds was confirmed by gas chromatography- olfactometry. The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop...

  13. SPOILAGE BACTERIA AND QUALITY INDEX METHOD SCORE IN REARED GILTHEAD SEABREAM

    Directory of Open Access Journals (Sweden)

    A. Panebianco

    2008-12-01

    Full Text Available A model to predict the Quality Index Method (QIM score increase during the storage was set for Sparus aurata. In this regard, 126 specimens were analysed during the storage in ice, enumerating the spoilage bacteria in Iron Agar as well as evaluating the QIM. The growth curves and the observed QIM scores were used to calculate (fitting method the terms a and b which relate the bacterial growth to the predicted QIM values. The presumptive Pseudomonas better explains the QIM trends; furthermore the model was validated with regard to other QIM curves obtained during a temperature fluctuating storage, introducing into the predictive system the secondary model for Shewanella spp. (Dalgard, 1995 and Rasmussen et al. (2002. In this case, the model produced a good estimation of the observed QIM.

  14. Study on the spoilage potential ofPseudomonas fluorescenson salmon stored at different temperatures.

    Science.gov (United States)

    Xie, Jing; Zhang, Zhen; Yang, Sheng-Ping; Cheng, Ying; Qian, Yun-Fang

    2018-01-01

    The bacterial kinetics and quality indexes [sensory quality, total volatile basic nitrogen (TVB-N), thiobarbituric acid value, biogenic amine, and amino acids] were analyzed on salmon inoculated with Pseudomonas fluorescens during storage under different temperatures (30, 10, and 4 °C). The bacterial kinetics revealed that P. fluorescens showed a steady growth at low temperatures (10 and 4 °C). The TVB-N yield factors of the sample stored at 4 °C indicated that each bacterial cell of P. fluorescens displayed greater spoilage activity at low temperatures. A remarkable correlation was found between the production of biogenic amines and bacterial counts. The results also highlighted that P. fluorescens cultured at 4 °C had higher demand for amino acids.

  15. Interaction of monolaurin, eugenol and sodium citrate on growth of common meat spoilage and pathogenic organisms.

    Science.gov (United States)

    Blaszyk, M; Holley, R A

    1998-02-17

    Interactions of monolaurin, eugenol (phenolic compound) and sodium citrate (chelator) on the growth of six organisms including common meat spoilage (Lactobacillus curvatus, Lactobacillus sake, Leuconostoc mesenteroides, Brochothrix thermosphacta) and pathogenic (Escherichia coli O157:H7 and Listeria monocytogenes) organisms were investigated. The combinations of 100 to 250 ppm monolaurin with 500 and 1000 ppm eugenol, and 0.2 and 0.4% sodium citrate were more effective than each component separately. More than one combination prevented detectable growth of each organism. Lactic acid bacteria (LAB) and E. coli O157:H7 were most resistant and L. monocytogenes and B. thermosphacta most sensitive to control by the chosen combinations. The presence of sodium citrate was necessary to yield potent inhibition of Lb. curvatus and Lb. sake growth by the monolaurin and eugenol combinations.

  16. Microbiological spoilage and investigation of volatile profile during storage of sea bream fillets under various conditions.

    Science.gov (United States)

    Parlapani, Foteini F; Mallouchos, Athanasios; Haroutounian, Serkos A; Boziaris, Ioannis S

    2014-10-17

    Volatile organic compound (VOC) profile was determined during storage of sea bream (Sparus aurata) fillets under air and Modified Atmosphere Packaging (MAP - CO2/O2/N2: 60/10/30) at 0, 5 and 15°C. Microbiological, TVB-N (Total Volatile Base Nitrogen) and sensory changes were also monitored. Shelf-life of sea bream fillets stored under air was 14, 5 and 2days (d) at 0, 5 and 15°C respectively, while under MAP was 18, 8, and 2d at 0, 5 and 15°C respectively. At the end of shelf life, the total microbial population ranged from 7.5 to 8.5logcfu/g. Pseudomonas spp. were among the dominant spoilage microorganisms in all cases, however growth of Brochothrix thermosphacta and Lactic Acid Bacteria (LAB) were favoured under MAP compared to air. TVB-N production was favoured at higher temperatures and under air compared to lower temperatures and MAP. TVB-N increased substantially from the middle of storage and its value never reached concentrations higher than 30-35mgN/100g, which is the legislation limit, making it a poor chemical spoilage index (CSI). A lot of alcohols, aldehydes, ketones and ethyl esters that were detected in the present study have been reported as bacterial metabolites, others as products of chemical oxidation while others as aroma constituents. VOCs such as 3-methylbutanal, acetic acid, ethanol, ethyl esters of isovaleric and 2-methylbutyric acids, 1-penten-3-ol, 1-octen-3-ol and cis-4-heptenal appeared from the early or middle stages and increased until the end of storage. From those only 3-methylbutanal, acetic acid, ethanol and the ethyl esters have been reported as microbial origin, making them potential CSI candidates of sea bream fillets. Copyright © 2014. Published by Elsevier B.V.

  17. Aggregation of the rhizospheric bacterium Azospirillum brasilense in response to oxygen

    Science.gov (United States)

    Abdoun, Hamid; McMillan, Mary; Pereg, Lily

    2016-04-01

    Azospirillum brasilense spp. have ecological, scientific and agricultural importance. As model plant growth promoting rhizobacteria they interact with a large variety of plants, including important food and cash crops. Azospirillum strains are known for their production of plant growth hormones that enhance root systems and for their ability to fix nitrogen. Azospirillum cells transform in response to environmental cues. The production of exopolysaccharides and cell aggregation during cellular transformation are important steps in the attachment of Azospirillum to roots. We investigate signals that induce cellular transformation and aggregation in the Azospirillum and report on the importance of oxygen to the process of aggregation in this rhizospheric bacterium.

  18. Characterization of specific spoilage organisms (SSOs) in vacuum-packed ham by culture-plating techniques and MiSeq next-generation sequencing technologies.

    Science.gov (United States)

    Piotrowska-Cyplik, Agnieszka; Myszka, Kamila; Czarny, Jakub; Ratajczak, Katarzyna; Kowalski, Ryszard; Biegańska-Marecik, Róża; Staninska-Pięta, Justyna; Nowak, Jacek; Cyplik, Paweł

    2017-01-01

    Knowledge regarding microaerophilic and anaerobic specific spoilage organisms (SSOs) is crucial for an appropriate evaluation of vacuum-packed ham. The objective of this study was to characterize the SSO community in vacuum-packed ham by a culture-dependent technique and MiSeq next-generation sequencing (NGS) platform. The relation between changes among the SSO group in the ham and changes in sensory characteristics of the product was also assessed. In the study, conventional microbiological analyses were employed in order to establish the participation of several groups of microorganisms in the deterioration of vacuum-packed ham. The diversity of the SSO group in the product was further assessed with the use of MiSeq NGS technology. The bacteria identified in sliced cooked ham belonged mostly to four phyla, namely Actinobacteria, Proteobacteria, Firmicutes and Bacteroidetes. A temperature of 4 °C favoured the development of mesophilic and psychrophilic/psychrotrophic flora, mainly Lactobacillaceae, Enterobacteriaceae and Micrococcaceae families. A high ratio of Brochothrix thermosphacta species and new, cold-tolerant Clostridium spp. was also observed. The growth of these microorganisms facilitated changes in the pH value and organoleptic characteristics of the product. This study confirms that the combination of culturing and MiSeq NGS technology improves the microbial evaluation of food. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  19. Lactococcus lactis and Lactobacillus sakei as bio-protective culture to eliminate Leuconostoc mesenteroides spoilage and improve the shelf life and sensorial characteristics of commercial cooked bacon.

    Science.gov (United States)

    Comi, Giuseppe; Andyanto, Debbie; Manzano, Marisa; Iacumin, Lucilla

    2016-09-01

    Cooked bacon is a typical Italian meat product. After production, cooked bacon is stored at 4 ± 2 °C. During storage, the microorganisms that survived pasteurisation can grow and produce spoilage. For the first time, we studied the cause of the deterioration in spoiled cooked bacon compared to unspoiled samples. Moreover, the use of bio-protective cultures to improve the quality of the product and eliminate the risk of spoilage was tested. The results show that Leuconostoc mesenteroides is responsible for spoilage and produces a greening colour of the meat, slime and various compounds that result from the fermentation of sugars and the degradation of nitrogen compounds. Finally, Lactococcus lactis spp. lactis and Lactobacillus sakei were able to reduce the risk of Leuconostoc mesenteroides spoilage. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Complete genome sequence of Agarivorans gilvus WH0801(T), an agarase-producing bacterium isolated from seaweed.

    Science.gov (United States)

    Zhang, Pujuan; Rui, Junpeng; Du, Zongjun; Xue, Changhu; Li, Xiangzhen; Mao, Xiangzhao

    2016-02-10

    Agarivorans gilvus WH0801(T), an agarase-producing bacterium, was isolated from the surface of seaweed. Here, we present the complete genome sequence, which consists of one circular chromosome of 4,416,600 bp with a GC content of 45.9%. This genetic information will provide insight into biotechnological applications of producing agar for food and industry. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Radiation preservation of food. Efficiency and wholesomeness

    International Nuclear Information System (INIS)

    Saint-Lebe, Louis; Raffi, Jacques; Henon, Yves.

    1982-03-01

    This document reviews the applications of ionizing radiations in the food industry. The two first chapters feature the characteristics of the three types of ionizing radiations that can be used (gamma rays from cobalt 60 and caesium 137, X rays, electron beams) and their action on foodstuff and the food spoilage organisms. The third chapter is a review of toxicological studies based on two complementary approaches: animal assays and studies on the radiolysis products. It provides the evidences that lead the international experts to regard irradiated food as safe for human consumption. In the fourth chapter, the problems of identification of irradiated food and the possible controls are exposed. The authors conclude by suggesting the measures that would allow commercial application in France [fr

  2. Invasive Fungal Infections Acquired from Contaminated Food or Nutritional Supplements: A Review of the Literature.

    Science.gov (United States)

    Benedict, Kaitlin; Chiller, Tom M; Mody, Rajal K

    2016-07-01

    Fungi are an integral part of the natural environment and, therefore, play many roles in relation to food: some fungi are used in food production, some are food sources themselves, and some are agents of food spoilage. Some fungi that contaminate food can also be harmful to human health. The harmful but noninfectious health consequences of mycotoxins have been well-characterized, but the extent to which fungi in food pose a risk for invasive infections is unknown. We conducted a literature review to identify cases of invasive fungal infections (IFIs) believed to have resulted from ingestion or inhalation of food, beverages, or dietary supplements (excluding Saccharomyces infections). We identified 11 publications describing cases or small outbreaks of IFIs related to foods or beverages and three describing IFIs related to dietary supplements. These food-associated IFIs were predominantly mold infections, and the few yeast infections were associated with dairy products. Suspected foodborne IFIs appear to be rare, but are increasingly described in the electronically searchable literature. They are associated with a variety of foods, are due to a variety of fungal pathogens, and primarily occur in persons with immunosuppressive conditions or other predisposing factors. Various guidelines for high-risk patients recommend avoidance of certain food products that may contain high levels of fungi, but further work is needed to evaluate the effectiveness of these restrictive diets in preventing fungal infections. The relationships between food spoilage, food insecurity, and IFI risk are another area that may warrant further exploration.

  3. Antioxidants in foods: state of the science important to the food industry.

    Science.gov (United States)

    Finley, John W; Kong, Ah-Ng; Hintze, Korry J; Jeffery, Elizabeth H; Ji, Li Li; Lei, Xin Gen

    2011-07-13

    Antioxidant foods and ingredients are an important component of the food industry. In the past, antioxidants were used primarily to control oxidation and retard spoilage, but today many are used because of putative health benefits. However, the traditional message that oxidative stress, which involves the production of reactive oxygen species (ROS), is the basis for chronic diseases and aging is being reexamined. Accumulating evidence suggests that ROS exert essential metabolic functions and that removal of too many ROS can upset cell signaling pathways and actually increase the risk of chronic disease. It is imperative that the food industry be aware of progress in this field to present the science relative to foods in a forthright and clear manner. This may mean reexamining the health implications of adding large amounts of antioxidants to foods.

  4. Experimental evolution of aging in a bacterium

    Directory of Open Access Journals (Sweden)

    Stearns Stephen C

    2007-07-01

    Full Text Available Abstract Background Aging refers to a decline in reproduction and survival with increasing age. According to evolutionary theory, aging evolves because selection late in life is weak and mutations exist whose deleterious effects manifest only late in life. Whether the assumptions behind this theory are fulfilled in all organisms, and whether all organisms age, has not been clear. We tested the generality of this theory by experimental evolution with Caulobacter crescentus, a bacterium whose asymmetric division allows mother and daughter to be distinguished. Results We evolved three populations for 2000 generations in the laboratory under conditions where selection was strong early in life, but very weak later in life. All populations evolved faster growth rates, mostly by decreasing the age at first division. Evolutionary changes in aging were inconsistent. The predominant response was the unexpected evolution of slower aging, revealing the limits of theoretical predictions if mutations have unanticipated phenotypic effects. However, we also observed the spread of a mutation causing earlier aging of mothers whose negative effect was reset in the daughters. Conclusion Our results confirm that late-acting deleterious mutations do occur in bacteria and that they can invade populations when selection late in life is weak. They suggest that very few organisms – perhaps none- can avoid the accumulation of such mutations over evolutionary time, and thus that aging is probably a fundamental property of all cellular organisms.

  5. Spectral imaging for contamination detection in food

    DEFF Research Database (Denmark)

    Carstensen, Jens Michael

    application of the technique is finding anomalies I supposedly homogeneous matter or homogeneous mixtures. This application occurs frequently in the food industry when different types of contamination are to be detected. Contaminants could be e.g. foreign matter, process-induced toxins, and microbiological...... spoilage. Many of these contaminants may be detected in the wavelength range visible to normal silicium-based camera sensors i.e. 350-1050 nm with proper care during sample preparation, sample presentation, image acquisition and analysis. This presentation will give an introduction to the techniques behind...

  6. Comparison of extracellular DNase- and protease-producing spoilage bacteria isolated from Delaware pond-sourced and retail channel catfish (Ictalurus punctatus).

    Science.gov (United States)

    Hickey, Michael E; Accumanno, Gina M; McIntosh, Dennis M; Blank, Grant S; Lee, Jung-Lim

    2015-03-30

    Spoilage of fishery products begins immediately following filleting due to microbial growth that degrades fish tissue quality prior to consumption. Extensive research has been conducted to identify such bacterial populations. A better understanding of the mechanisms involved in fish spoilage is necessary as a novel remedy for microbial spoilage inhibition has yet to be established for fish tissue. The present study identified, for the first time, bacterial populations that produce extracellular DNase and protease from Delaware and local retail distributed channel catfish (Ictalurus punctatus) fillets. A clear trend was identified between bacteria derived from catfish filleted under aseptic conditions where Pseudomonas was the dominant genus. Bacteria isolated from retail catfish contained high quantities of DNase-producing isolates, in contrast to aseptic-filleted catfish tissue which had none. Both types of catfish sample maintained high populations of protease-producing bacterial colonies throughout the duration of the study. Most bacteria isolated from catfish intestines exhibited DNase production with no protease production. Specific spoilage organism populations were significantly higher on retail-derived catfish in comparison to lab-filleted Delaware cultured catfish tissue. It is suggested that DNase production and protease production contribute to the spoilage of fish tissue as a result of mishandling and septic filleting being the major cause of rapid catfish tissue spoilage. © 2014 Society of Chemical Industry.

  7. Food preservation : relevance of nuclear techniques to developing nations

    International Nuclear Information System (INIS)

    Aiyar, A.S.; Sundaram, K.

    1977-01-01

    The usefulness of radiation processes over conventional methods for preservation of foods has been discussed in detail. There are five distinct objectives that can be achieved by exposing food to ionising radiation, and these are : (a) total elimination of food spoilage or disease-causing organisms, thus confering indefinite stability on the pre-packaged food; (b) significant reduction of spoilage microorganisms to enable extended shelf-life; (c) inactivation of organisms that poses public health hazards; (d) elimination of losses in dry foods due to insect infestation, by killing the eggs and their insects; and (e) control of post-harvest physiological processes such as sprouting, ripening etc. For highly perishable sea foods, such as, Bombay Duck, irradiation represents the only possible soultion to the problem of its preservation in the fresh state. An evaluation of the wholesomeness of irradiated mackerel is currently underway in India as part of an international effort at obtaining such data collectively, to minimise the enormour costs involved in such experimentation. Recently, clearances have been authorised for the release of irradiated foods for human consumption. A summary of international approvals for radiation preservation processes is presented. (A.K.)

  8. Lysinibacillus louembei sp. nov., a spore-forming bacterium isolated from Ntoba Mbodi, alkaline fermented leaves of cassava from the Republic of the Congo

    DEFF Research Database (Denmark)

    Ouoba, Labia Irène I.; Mbozo, Alain B. Vouidibio; Thorsen, Line

    2015-01-01

    Investigation of the microbial diversity of Ntoba Mbodi, an African food made from the alkaline fermentation of cassava leaves, revealed the presence of a Gram-positive, catalase-positive, aerobic, motile and rod-shaped endospore-forming bacterium (NM73) with unusual phenotypic and genotypic...

  9. Occurrence and Species Distribution of Strictly Anaerobic Bacterium Pectinatus in Brewery Bottling Halls

    Czech Academy of Sciences Publication Activity Database

    Matoulková, D.; Kosař, K.; Slabý, M.; Sigler, Karel

    2012-01-01

    Roč. 70, č. 4 (2012), s. 262-267 ISSN 0361-0470 Institutional support: RVO:61388971 Keywords : Beer spoilage * Biofilm * Conveyor belt Subject RIV: EE - Microbiology, Virology Impact factor: 1.000, year: 2012

  10. Virgibacillus kimchii sp. nov., a halophilic bacterium isolated from kimchi.

    Science.gov (United States)

    Oh, Young Joon; Jang, Ja-Young; Lim, Seul Ki; Kwon, Min-Sung; Lee, Jieun; Kim, NamHee; Shin, Mi-Young; Park, Hyo Kyeong; Seo, Myung-Ji; Choi, Hak-Jong

    2017-12-01

    A Gram-stain-positive, halophilic, rod-shaped, non-motile, spore forming bacterium, strain NKC1-2 T , was isolated from kimchi, a Korean fermented food. Comparative analysis based on 16S rRNA gene sequence demonstrated that the isolated strain was a species of the genus Virgibacillus. Strain NKC1-2 T exhibited high level of 16S rRNA gene sequence similarity with the type strains of Virgibacillus xinjiangensis SL6-1 T (96.9%), V. sediminis YIM kkny3 T (96.8%), and V. salarius SA-Vb1 T (96.7%). The isolate grew at pH 6.5-10.0 (optimum, pH 8.5-9.0), 0.0-25.0% (w/v) NaCl (optimum, 10-15% NaCl), and 15-50°C (optimum, 37°C). The major menaquinone in the strain was menaquinone-7, and the main peptidoglycan of the strain was meso-diaminopimelic acid. The predominant fatty acids of the strain were iso-C 14:0 , anteisio-C 15:0 , iso- C 15:0 , and iso-C 16:0 (other components were < 10.0%). The polar lipids consisted of diphosphatidylglycerol and phosphatidylglycerol. The genomic DNA G + C content of NKC1-2 T was 42.5 mol%. On the basis of these findings, strain NKC1-2 T is proposed as a novel species in the genus Virgibacillus, for which the name Virgibacillus kimchii sp. nov. is proposed (=KACC 19404 T =JCM 32284 T ). The type strain of Virgibacillus kimchii is NKC1-2T.

  11. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Non-Culture Based Methods

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M.; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure and cheese like aromas is a challenge of significant economical impact for the pickling industry. Previous culture based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, four gram positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp. and Propionibacterium and one gram-negative genus, Pectinatus as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 months. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota. Practical Application Understanding of the underlying microbiology and biochemistry driving FCS is essential to enhancing the sodium chloride (NaCl)-free cucumber fermentation technology and in

  12. The Biodiversity of the Microbiota Producing Heat-Resistant Enzymes Responsible for Spoilage in Processed Bovine Milk and Dairy Products

    Science.gov (United States)

    Machado, Solimar G.; Baglinière, François; Marchand, Sophie; Van Coillie, Els; Vanetti, Maria C. D.; De Block, Jan; Heyndrickx, Marc

    2017-01-01

    Raw bovine milk is highly nutritious as well as pH-neutral, providing the ideal conditions for microbial growth. The microbiota of raw milk is diverse and originates from several sources of contamination including the external udder surface, milking equipment, air, water, feed, grass, feces, and soil. Many bacterial and fungal species can be found in raw milk. The autochthonous microbiota of raw milk immediately after milking generally comprises lactic acid bacteria such as Lactococcus, Lactobacillus, Streptococcus, and Leuconostoc species, which are technologically important for the dairy industry, although they do occasionally cause spoilage of dairy products. Differences in milking practices and storage conditions on each continent, country and region result in variable microbial population structures in raw milk. Raw milk is usually stored at cold temperatures, e.g., about 4°C before processing to reduce the growth of most bacteria. However, psychrotrophic bacteria can proliferate and contribute to spoilage of ultra-high temperature (UHT) treated and sterilized milk and other dairy products with a long shelf life due to their ability to produce extracellular heat resistant enzymes such as peptidases and lipases. Worldwide, species of Pseudomonas, with the ability to produce these spoilage enzymes, are the most common contaminants isolated from cold raw milk although other genera such as Serratia are also reported as important milk spoilers, while for others more research is needed on the heat resistance of the spoilage enzymes produced. The residual activity of extracellular enzymes after high heat treatment may lead to technological problems (off flavors, physico-chemical instability) during the shelf life of milk and dairy products. This review covers the contamination patterns of cold raw milk in several parts of the world, the growth potential of psychrotrophic bacteria, their ability to produce extracellular heat-resistant enzymes and the consequences for

  13. First study on the formation and resuscitation of viable but nonculturable state and beer spoilage capability of Lactobacillus lindneri.

    Science.gov (United States)

    Liu, Junyan; Li, Lin; Li, Bing; Peters, Brian M; Deng, Yang; Xu, Zhenbo; Shirtliff, Mark E

    2017-06-01

    This study aimed to investigate the spoilage capability of Lactobacillus lindneri during the induction and resuscitation of viable but nonculturable (VBNC) state. L. lindneri strain was identified by sequencing the PCR product (amplifying 16S rRNA gene) using ABI Prism 377 DNA Sequencer. During the VBNC state induction by low temperature storage and beer adaption, total, culturable, and viable cells were assessed by acridine orange direct counting, plate counting, and Live/Dead BacLight bacterial viability kit, respectively. Organic acids and diacetyl concentration were measured by reversed-phase high performance liquid chromatography and head dpace gas chromatography, respectively. VBNC state of L. lindneri was successfully induced by both beer adaption and low temperature storage, and glycerol frozen stock was the optimal way to maintain the VBNC state. Addition of catalase was found to be an effective method for the resuscitation of VBNC L. lindneri cells. Furthermore, spoilage capability remained similar during the induction and resuscitation of VBNC L. lindneri. This is the first report of induction by low temperature storage and resuscitation of VBNC L. lindneri strain, as well as the first identification of spoilage capability of VBNC and resuscitated L. lindneri cells. This study indicated that the potential colonization of L. lindneri strain in brewery environment, formation and resuscitation of VBNC state, as well as maintenance in beer spoilage capability, may be an important risk factor for brewery environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. The Biodiversity of the Microbiota Producing Heat-Resistant Enzymes Responsible for Spoilage in Processed Bovine Milk and Dairy Products.

    Science.gov (United States)

    Machado, Solimar G; Baglinière, François; Marchand, Sophie; Van Coillie, Els; Vanetti, Maria C D; De Block, Jan; Heyndrickx, Marc

    2017-01-01

    Raw bovine milk is highly nutritious as well as pH-neutral, providing the ideal conditions for microbial growth. The microbiota of raw milk is diverse and originates from several sources of contamination including the external udder surface, milking equipment, air, water, feed, grass, feces, and soil. Many bacterial and fungal species can be found in raw milk. The autochthonous microbiota of raw milk immediately after milking generally comprises lactic acid bacteria such as Lactococcus , Lactobacillus , Streptococcus , and Leuconostoc species, which are technologically important for the dairy industry, although they do occasionally cause spoilage of dairy products. Differences in milking practices and storage conditions on each continent, country and region result in variable microbial population structures in raw milk. Raw milk is usually stored at cold temperatures, e.g., about 4°C before processing to reduce the growth of most bacteria. However, psychrotrophic bacteria can proliferate and contribute to spoilage of ultra-high temperature (UHT) treated and sterilized milk and other dairy products with a long shelf life due to their ability to produce extracellular heat resistant enzymes such as peptidases and lipases. Worldwide, species of Pseudomonas , with the ability to produce these spoilage enzymes, are the most common contaminants isolated from cold raw milk although other genera such as Serratia are also reported as important milk spoilers, while for others more research is needed on the heat resistance of the spoilage enzymes produced. The residual activity of extracellular enzymes after high heat treatment may lead to technological problems (off flavors, physico-chemical instability) during the shelf life of milk and dairy products. This review covers the contamination patterns of cold raw milk in several parts of the world, the growth potential of psychrotrophic bacteria, their ability to produce extracellular heat-resistant enzymes and the consequences

  15. Antifungal Activity of Selected Lactic Acid Bacteria and Propionic Acid Bacteria against Dairy-Associated Spoilage Fungi

    DEFF Research Database (Denmark)

    Aunsbjerg, Stina Dissing

    Bacterial cultures of lactic and propionic acid bacteria are widely used in fermented products including dairy products. Spoilage fungi may constitute a quality and safety issue in these products. The antifungal properties of some lactic and propionic acid bacteria make them potential candidates...... diacetyl and lactic acid, 6 antifungal hydroxy acids were identified. Of these, 3 have previously been reported from antifungal lactic acid bacteria, whereas the other 3 hydroxy acids have not previously been reported produced by antifungal lactic acid bacteria....

  16. Bacterial Ecology of Fermented Cucumber Rising pH Spoilage as Determined by Nonculture-Based Methods.

    Science.gov (United States)

    Medina, Eduardo; Pérez-Díaz, Ilenys M; Breidt, Fred; Hayes, Janet; Franco, Wendy; Butz, Natasha; Azcarate-Peril, María Andrea

    2016-01-01

    Fermented cucumber spoilage (FCS) characterized by rising pH and the appearance of manure- and cheese-like aromas is a challenge of significant economical impact for the pickling industry. Previous culture-based studies identified the yeasts Pichia manshurica and Issatchenkia occidentalis, 4 Gram-positive bacteria, Lactobacillus buchneri, Lactobacillus parrafaraginis, Clostridium sp., and Propionibacterium and 1 Gram-negative genus, Pectinatus, as relevant in various stages of FCS given their ability to metabolize lactic acid. It was the objective of this study to augment the current knowledge of FCS using culture-independent methods to microbiologically characterize commercial spoilage samples. Ion Torrent data and 16S rRNA cloning library analyses of samples collected from commercial fermentation tanks confirmed the presence of L. rapi and L. buchneri and revealed the presence of additional species involved in the development of FCS such as Lactobacillus namurensis, Lactobacillus acetotolerans, Lactobacillus panis, Acetobacter peroxydans, Acetobacter aceti, and Acetobacter pasteurianus at pH below 3.4. The culture-independent analyses also revealed the presence of species of Veillonella and Dialister in spoilage samples with pH above 4.0 and confirmed the presence of Pectinatus spp. during lactic acid degradation at the higher pH. Acetobacter spp. were successfully isolated from commercial samples collected from tanks subjected to air purging by plating on Mannitol Yeast Peptone agar. In contrast, Lactobacillus spp. were primarily identified in samples of FCS collected from tanks not subjected to air purging for more than 4 mo. Thus, it is speculated that oxygen availability may be a determining factor in the initiation of spoilage and the leading microbiota. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

  17. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    Energy Technology Data Exchange (ETDEWEB)

    Dees, C.; Ringleberg, D.; Scott, T.C. [Oak Ridge National Lab., TN (United States); Phelps, T. [Univ. of Tennessee, Knoxville, TN (United States)

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  18. Current Demands for Food-Approved Liposome Nanoparticles in Food and Safety Sector

    Directory of Open Access Journals (Sweden)

    Shruti Shukla

    2017-12-01

    Full Text Available Safety of food is a noteworthy issue for consumers and the food industry. A number of complex challenges associated with food engineering and food industries, including quality food production and safety of the food through effective and feasible means can be explained by nanotechnology. However, nanoparticles have unique physicochemical properties compared to normal macroparticles of the same composition and thus could interact with living system in surprising ways to induce toxicity. Further, few toxicological/safety assessments have been performed on nanoparticles, thereby necessitating further research on oral exposure risk prior to their application to food. Liposome nanoparticles are viewed as attractive novel materials by the food and medical industries. For example, nanoencapsulation of bioactive food compounds is an emerging application of nanotechnology. In several food industrial practices, liposome nanoparticles have been utilized to improve flavoring and nutritional properties of food, and they have been examined for their capacity to encapsulate natural metabolites that may help to protect the food from spoilage and degradation. This review focuses on ongoing advancements in the application of liposomes for food and pharma sector.

  19. Current Demands for Food-Approved Liposome Nanoparticles in Food and Safety Sector.

    Science.gov (United States)

    Shukla, Shruti; Haldorai, Yuvaraj; Hwang, Seung Kyu; Bajpai, Vivek K; Huh, Yun Suk; Han, Young-Kyu

    2017-01-01

    Safety of food is a noteworthy issue for consumers and the food industry. A number of complex challenges associated with food engineering and food industries, including quality food production and safety of the food through effective and feasible means can be explained by nanotechnology. However, nanoparticles have unique physicochemical properties compared to normal macroparticles of the same composition and thus could interact with living system in surprising ways to induce toxicity. Further, few toxicological/safety assessments have been performed on nanoparticles, thereby necessitating further research on oral exposure risk prior to their application to food. Liposome nanoparticles are viewed as attractive novel materials by the food and medical industries. For example, nanoencapsulation of bioactive food compounds is an emerging application of nanotechnology. In several food industrial practices, liposome nanoparticles have been utilized to improve flavoring and nutritional properties of food, and they have been examined for their capacity to encapsulate natural metabolites that may help to protect the food from spoilage and degradation. This review focuses on ongoing advancements in the application of liposomes for food and pharma sector.

  20. Effect of high-oxygen and oxygen-free modified atmosphere packaging on the spoilage process of poultry breast fillets.

    Science.gov (United States)

    Rossaint, Sonja; Klausmann, Sonja; Kreyenschmidt, Judith

    2015-01-01

    A comparison was made of the effect of atmospheres containing high oxygen (70% O2 and 30% CO2) or high nitrogen (70% N2 and 30% CO2) on the spoilage process during storage (at 4°C) of poultry fillets. Four samples of each gas atmosphere were analyzed at 7 sample points during storage. For this analysis, the growth of typical spoilage organisms (Brochothrix thermosphacta, Pseudomonas spp., Enterobacteriaceae, and Lactobacilli spp.) and total viable count (TVC) were analyzed and modeled by using the Gompertz function. Sensory analyses of the poultry samples were carried out by trained sensory panelists to analyze color, odor, texture, drip loss, and general appearance. The composition of the spoilage flora differed between the oxygen-free atmosphere and the high-oxygen atmosphere. Anaerobic conditions favored the growth of Lactobacilli spp., whereas aerobic gas composition favored the growth of B. thermosphacta. However, no significant difference (Patmosphere in comparison to a high-nitrogen atmosphere. These results indicate that high-oxygen packaging has no additional beneficial effect on the quality maintenance and shelf life of fresh poultry fillets. © 2014 Poultry Science Association Inc.

  1. Lipidomics as an important key for the identification of beer-spoilage bacteria.

    Science.gov (United States)

    Řezanka, T; Matoulková, D; Benada, O; Sigler, K

    2015-06-01

    Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) was used for characterizing intact plasmalogen phospholipid molecules in beer-spoilage bacteria. Identification of intact plasmalogens was carried out using collision-induced dissociation and the presence of suitable marker molecular species, both qualitative and quantitative, was determined in samples containing the anaerobic bacteria Megasphaera and Pectinatus. Using selected ion monitoring (SIM), this method had a limit of detection at 1 pg for the standard, i.e. 1-(1Z-octadecenyl)-2-oleoyl-sn-glycero-3-phosphoethanolamine and be linear in the range of four orders of magnitude from 2 pg to 20 ng. This technique was applied to intact plasmalogen extracts from the samples of contaminated and uncontaminated beer without derivatization and resulted in the identification of contamination of beer by Megasphaera and Pectinatus bacteria. The limit of detection was about 830 cells of anaerobic bacteria, i.e. bacteria containing natural cyclopropane plasmalogenes (c-p-19:0/15:0), which is the majority plasmalogen located in both Megasphaera and Pectinatus. The SIM ESI-MS method has been shown to be useful for the analysis of low concentration of plasmalogens in all biological samples, which were contaminated with anaerobic bacteria, e.g. juice, not only in beer. Significance and impact of the study: Electrospray ionization-tandem mass spectrometry (ESI-MS/MS) using collision-induced dissociation was used to characterize intact plasmalogen phospholipid molecules in beer-spoilage anaerobic bacteria Megasphaera and Pectinatus. Using selected ion monitoring (SIM), this method has a detection limit of 1 pg for the standard 1-(1Z-octadecenyl)-2-oleoyl-sn-glycero-3-phosphoethanolamine and is linear within four orders of magnitude (2 pg to 20 ng). The limit of detection was about 830 cells of bacteria containing natural cyclopropane plasmalogen (c-p-19:0/15:0). SIM ESI-MS method is useful for analyzing low

  2. Food irradiation: advantages and limitations

    International Nuclear Information System (INIS)

    Hernandes, N.K.; Vital, H. de C.; Sabaa-Srur, A.U.O.

    2003-01-01

    Food irradiation is a physical method of processing food (e.g. freezing, canning). It has been thoroughly researched over the last four decades and is recognized as a safe and wholesome method. It has the potential both of disinfesting dried food to reduce storage losses and disinfesting fruits and vegetables to meet quarantine requirements for export trade. Low doses of irradiation inhibit spoilage losses due to sprouting of root and tuber crops. Food- borne diseases due to contamination by pathogenic microorganisms and parasites of meat, poultry, fish, fishery products and spices are on the increase. Irradiation of these solid foods can decontaminate them of pathogenic organisms and thus provide safe food to the consumer. Irradiation can successfully replace the fumigation treatment of cocoa beans and coffee beans and disinfest dried fish, dates, dried fruits, etc. One of the most important advantages of food irradiation processing is that it is a coldprocess which does not significantly alter physico-chemical characters of the treated product. It can be applied to food after its final packaging. Similar to other physical processes of food processing, (e.g. canning, freezing), irradiation is a capital intensive process. Thus, adequate product volume must be made available in order to maximize the use of the facility and minimize the unit cost of treatment. Lack of harmonization of regulations among the countries which have approved irradiated foods hampers the introduction of this technique for international trade. Action at the international level has to be taken in order to remedy this situation. One of the important limitations of food irradiation processing is its slow acceptance by consumers, due inter alia to a perceived association with radioactivity. The food industry tends to be reluctant to use the technology in view of uncertainties regarding consumer acceptance of treated foods. Several market testing and consumer acceptance studies have been carried

  3. Use of ionizing radiation for preservation of food and feed products

    International Nuclear Information System (INIS)

    Josephson, E.S.; Brynjolfsson, A.; Wierbicki, E.

    1975-01-01

    Exposing food to ionizing radiation can contribute to closing the worldwide food deficit by reducing food spoilage losses, by making available more food of higher nutritional quality (animal protein food) to more people, and by keeping prices down by reducing losses. Because ionizing radiation kills disease-causing organisms, it can reduce the incidence of food-borne diseases. It also reduces our dependence upon some of the chemical additives, such as nitrites and nitrates, now being questioned by health authorities to control food spoilage and food-borne diseases. The three basic types of ionizing radiation used for processing of food are electrons (10 MeV maximum energy), X-rays (5 MeV maximum energy) produced by electrons in an X-ray target, and gamma rays from 60 Co and 137 Cs. Electrons, X-rays, and gamma rays cause ionization in the food by either the primary electrons or by the secondary electrons resulting from gamma or X-ray interactions in the food with little rise in temperature and little total chemical change. The ionized and activated molecules form unstable secondary products that kill the organisms. Another effect is to slow down post-harvest growth and maturation in some fruits and vegetables

  4. Public health aspects of food irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kaferstein, F. [Director, Programme of Food Safety and Food Aid, WHO, CH-1211, Geneva 27, (Switzerland)

    1997-12-31

    Post-harvest losses due to sprouting, insect infestation and spoilage by microorganisms is a serious problem in many countries and commonly aggravates the problem of food shortages. In addition, many developing countries also depend largely on agricultural produce, such as grain, tuber and tropical fruit, as major export crops to earn foreign exchange. The use of ionizing radiation as an effective means of disinfecting and/or prolonging the self-life of several food products has been well documented in a number of developing countries. The World health organization (WHO) encourages its Member States to consider all measures to eliminate or reduce food borne pathogens in food and improve their supplies of safe and nutritious food. In regard to its contribution to food safety, food irradiation may be one of the most significant contributions to public health to be made by food science and technology since the introduction of pasteurization. Because the promotion of a safe, nutritious and adequate food supply is an essential component of its primary health care strategy, WHO is concerned that the unwarranted rejection or limitation of this process may endanger public health and deprive consumers of the choice of foods processed for safety. (Author)

  5. Public health aspects of food irradiation

    International Nuclear Information System (INIS)

    Kaferstein, F.

    1997-01-01

    Post-harvest losses due to sprouting, insect infestation and spoilage by microorganisms is a serious problem in many countries and commonly aggravates the problem of food shortages. In addition, many developing countries also depend largely on agricultural produce, such as grain, tuber and tropical fruit, as major export crops to earn foreign exchange. The use of ionizing radiation as an effective means of disinfecting and/or prolonging the self-life of several food products has been well documented in a number of developing countries. The World health organization (WHO) encourages its Member States to consider all measures to eliminate or reduce food borne pathogens in food and improve their supplies of safe and nutritious food. In regard to its contribution to food safety, food irradiation may be one of the most significant contributions to public health to be made by food science and technology since the introduction of pasteurization. Because the promotion of a safe, nutritious and adequate food supply is an essential component of its primary health care strategy, WHO is concerned that the unwarranted rejection or limitation of this process may endanger public health and deprive consumers of the choice of foods processed for safety. (Author)

  6. Spoilage yeasts in Patagonian winemaking: molecular and physiological features of Pichia guilliermondii indigenous isolates.

    Science.gov (United States)

    Lopes, C A; Jofré, V; Sangorrín, M P

    2009-01-01

    Yeasts belonging to the genus Dekkera/Brettanomyces, especially the species Dekkera bruxellensis, have long been associated with the production of volatile phenols responsible for off-flavour in wines. According to recent reports, the species Pichia guilliermondii could also produce these compounds at the initial stages of fermentation. Based on the abundance of P. guilliermondii in Patagonian winemaking, we decided to study the relevance of indigenous isolates belonging to this species as wine spoilage yeast. Twenty-three indigenous isolates obtained from grape surfaces and red wine musts were analyzed in their capacity to produce volatile phenols on grape must. The relationship between molecular Random Amplified Polymorphic DNA (RAPD) and physiological (killer biotype) patterns detected in indigenous populations of P. guilliermondii and volatile phenol production was also evaluated. Different production levels of 4-ethylphenol, 4-vinylguaiacol and 4-ethylguaiacol were detected among the isolates; however, the values were always lower than those produced by the D. bruxellensis reference strain in the same conditions. High levels of 4-vinylphenol were detected among P. guilliermondii indigenous isolates. The combined use of RAPD and killer biotype allowed us to identify the isolates producing the highest volatile phenol levels.

  7. On-site monitoring of fish spoilage using vanadium pentoxide xerogel modified interdigitated gold electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Helali, S.; Abdelghani, A. [Unite de Recherche de Physique des Semiconducteurs et Capteurs, IPEST (Tunisia); Jaffrezic-Renault, N. [Laboratoire de Sciences Analytiques, Universite de Claude Bernard, Lyon (France); Trikalitis, P.N. [Department of Chemistry, University of Crete, 71 003, Heraklion Crete (Greece); Efstathiou, C.E. [Department of Chemistry, University of Athens, 157 71, Athens (Greece); Prodromidis, M.I., E-mail: mprodrom@cc.uoi.g [Department of Chemistry, University of Ioannina, 45 110, Ioannina (Greece)

    2010-05-30

    The development of a vanadium pentoxide xerogel (VXG)-based sensor for the detection of volatile inorganic (ammonia) and organic (dimethylamine, etc.) amines is described. The xerogel film was deposited on interdigitated gold electrodes by dip-coating using an aqueous solution of VXG. The morphology of the sensing layer, its interaction with ammonia, which was used as a model analyte throughout this work, as well as the regeneration of the surface of the sensor electrodes with vapors of HCl were examined with scanning electron microscopy and FTIR spectroscopy. Signal changes, due to changes of the RC-product of the electrochemical cell (Au-VXG-Au), as a result of its interactions with ammonia vapors, were probed with a portable, homemade charge meter, the Multipulser. Exposing the sensor electrodes to various concentrations of ammonia vapors resulted in proportional changes in the signal output. Finally, the proposed sensors were successfully used for on-site, real-time monitoring of fish spoilage in ambient conditions.

  8. Synergism between methods for inhibiting the spoilage of damp maize during storage

    International Nuclear Information System (INIS)

    Paster, N.; Menasherov, M.; Lacey, J.; Fanelli, C.

    1992-01-01

    Combinations of physical and chemical treatments were used in attempts to control mould development in maize grain containing 18% moisture. The treatments involved the use of propionic acid (0.1 or 0.2% v/w), γ-irradiation (1.0 or 2.0 kGy) and modified atmospheres (40% or 60% CO 2 in the presence of 20% oxygen) either separately or in combination. Mould colonisation during storage was assessed by dilution plating and measurements of respiratory CO 2 produced by grain samples. Spoilage was most effectively counteracted using a combination of 0.2% propionic acid with 2 kGy irradiation and 40% or 60% CO 2 , and this was more successful than any single component used separately, even after 45 days of treatment. Synergistic interaction between treatments thus allows the prospect of more efficient maize storage rather than employing single techniques. This concept could be important in practice because each component is employed only at a relatively low level of intensity. (author)

  9. Antimicrobial Activity of Various Plant Extracts on Pseudomonas Species Associated with Spoilage of Chilled Fish

    Directory of Open Access Journals (Sweden)

    Osan Bahurmiz

    2016-11-01

    Full Text Available The antimicrobial activity of various plant extracts on Pseudomonas bacteria isolated from spoiled chilled tilapia (Oreochromis sp. was evaluated in this study. In the first stage of this study, red tilapia was subjected to chilled storage (4°C for 3 weeks, and spoilage bacteria were isolated and identified from the spoiled fish. Pseudomonas was the dominant bacteria isolated from the spoiled fish and further identification revealed that P. putida, P. fluorescens and Pseudomonas spp. were the main species of this group. In the second stage, methanolic extracts of 15 selected plant species were screened for their antimicrobial activity, by agar disc diffusion method, against the Pseudomonas isolates. Results indicated that most of the extracts had different degrees of activity against the bacterial isolates. The strongest activity was exhibited by bottlebrush flower (Callistemon viminalis extract. This was followed by extracts from guava bark (Psidium guajava and henna leaf (Lawsonia inermis. Moderate antimicrobial activities were observed in extracts of clove (Syzygium aromaticum, leaf and peel of tamarind (Tamarindus indica, cinnamon bark (Cinnamomum zeylanicum, wild betel leaf (Piper sarmentosum and fresh thyme (Thymus spp.. Weak or no antimicrobial activity was observed from the remaining extracts. The potential antimicrobial activity shown by some plant extracts in this study could significantly contribute to the fish preservation.

  10. Identification and control of moulds responsible for black spot spoilage in dry-cured ham.

    Science.gov (United States)

    Alía, Alberto; Andrade, María J; Rodríguez, Alicia; Reyes-Prieto, Mariana; Bernáldez, Victoria; Córdoba, Juan J

    2016-12-01

    The aims of this work were to identify moulds responsible for black spot spoilage in the drying and cellar stages of dry-cured ham processing and evaluate the effectiveness of preventive actions for controlling this alteration. Four mould strains isolated from spoiled hams were identified by morphological characteristics and the ITS and β-tubulin sequencing. Two of them were Cladosporium oxysporum, one was C. cladosporioides and the remaining one was C. herbarum. These spoiling strains reproduced the black spots on dry-cured ham-based media and ham slices. Additionally, the effect of water activity (aw) conditions reached throughout dry-cured ham ripening and the activity of the protective culture Penicillium chrysogenum CECT 20922 against the spoiling moulds were evaluated. In the dry-cured ham model system the growth of the Cladosporium strains was minimised when the aw approaches 0.84 or in P. chrysogenum CECT 20922 inoculated dry-cured ham slices. Therefore such combination could be used to avoid the black spot formation in dry-cured ham. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Genetic discrimination of foodborne pathogenic and spoilage Bacillus spp. based on three housekeeping genes.

    Science.gov (United States)

    Caamaño-Antelo, S; Fernández-No, I C; Böhme, K; Ezzat-Alnakip, M; Quintela-Baluja, M; Barros-Velázquez, J; Calo-Mata, P

    2015-04-01

    Bacillus genus includes foodborne pathogenic and spoilage-associated species, such as Bacillus cereus, Bacillus licheniformis, Bacillus subtilis and Bacillus pumilus. Bacillus is also a heterogeneous genus that includes closely related species that are difficult to discriminate among, especially when well-conserved genes such as 16S rRNA and 23S rRNA are considered. The main goal of the present work was to study the usefulness of three housekeeping genes, the TU elongation factor (tuf), the DNA gyrase β subunit (gyrB) and the RNA polymerase β subunit (rpoB) genes, for use in differentiating among the most important foodborne Bacillus spp. sequences from 20 foodborne isolated Bacillus strains, and sequences belonging to different Bacillus spp. retrieved from the GenBank were analysed. In general terms, gyrB, rpoB and tuf gene regions for the strains considered in this study exhibited interspecific similarities of 57.8%, 67.23% and 77.66% respectively. Novel tufGPF and tufGPR universal primers targeted to the tuf gene were designed and proved to be useful for the amplification of all Bacillus spp considered. In conclusion, the tuf gene can be considered to be a good target for the differential characterisation of foodborne Bacillus species, especially for differentiating B. subtilis and B. cereus from other closely related species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. Assessment of system reliability for a stochastic-flow distribution network with the spoilage property

    Science.gov (United States)

    Lin, Yi-Kuei; Huang, Cheng-Fu; Yeh, Cheng-Ta

    2016-04-01

    In supply chain management, satisfying customer demand is the most concerned for the manager. However, the goods may rot or be spoilt during delivery owing to natural disasters, inclement weather, traffic accidents, collisions, and so on, such that the intact goods may not meet market demand. This paper concentrates on a stochastic-flow distribution network (SFDN), in which a node denotes a supplier, a transfer station, or a market, while a route denotes a carrier providing the delivery service for a pair of nodes. The available capacity of the carrier is stochastic because the capacity may be partially reserved by other customers. The addressed problem is to evaluate the system reliability, the probability that the SFDN can satisfy the market demand with the spoilage rate under the budget constraint from multiple suppliers to the customer. An algorithm is developed in terms of minimal paths to evaluate the system reliability along with a numerical example to illustrate the solution procedure. A practical case of fruit distribution is presented accordingly to emphasise the management implication of the system reliability.

  13. Brettanomyces yeasts--From spoilage organisms to valuable contributors to industrial fermentations.

    Science.gov (United States)

    Steensels, Jan; Daenen, Luk; Malcorps, Philippe; Derdelinckx, Guy; Verachtert, Hubert; Verstrepen, Kevin J

    2015-08-03

    Ever since the introduction of controlled fermentation processes, alcoholic fermentations and Saccharomyces cerevisiae starter cultures proved to be a match made in heaven. The ability of S. cerevisiae to produce and withstand high ethanol concentrations, its pleasant flavour profile and the absence of health-threatening toxin production are only a few of the features that make it the ideal alcoholic fermentation organism. However, in certain conditions or for certain specific fermentation processes, the physiological boundaries of this species limit its applicability. Therefore, there is currently a strong interest in non-Saccharomyces (or non-conventional) yeasts with peculiar features able to replace or accompany S. cerevisiae in specific industrial fermentations. Brettanomyces (teleomorph: Dekkera), with Brettanomyces bruxellensis as the most commonly encountered representative, is such a yeast. Whilst currently mainly considered a spoilage organism responsible for off-flavour production in wine, cider or dairy products, an increasing number of authors report that in some cases, these yeasts can add beneficial (or at least interesting) aromas that increase the flavour complexity of fermented beverages, such as specialty beers. Moreover, its intriguing physiology, with its exceptional stress tolerance and peculiar carbon- and nitrogen metabolism, holds great potential for the production of bioethanol in continuous fermentors. This review summarizes the most notable metabolic features of Brettanomyces, briefly highlights recent insights in its genetic and genomic characteristics and discusses its applications in industrial fermentation processes, such as the production of beer, wine and bioethanol. Copyright © 2015. Published by Elsevier B.V.

  14. [Application of Fourier transform infrared spectroscopy in identification of wine spoilage].

    Science.gov (United States)

    Zhao, Xian-De; Dong, Da-Ming; Zheng, Wen-Gang; Jiao, Lei-Zi; Lang, Yun

    2014-10-01

    In the present work, fresh and spoiled wine samples from three wines produced by different companies were studied u- sing Fourier transform infrared (FTIR) spectroscopy. We analyzed the physicochemical property change in the process of spoil- age, and then, gave out the attribution of some main FTIR absorption peaks. A novel determination method was explored based on the comparisons of some absorbance ratios at different wavebands although the absorbance ratios in this method were relative. Through the compare of the wine spectra before and after spoiled, the authors found that they were informative at the bands of 3,020~2,790, 1,760~1,620 and 1,550~800 cm(-1). In order to find the relation between these informative spectral bands and the wine deterioration and achieve the discriminant analysis, chemometrics methods were introduced. Principal compounds analysis (PCA) and soft independent modeling of class analogy (SIMCA) were used for classifying different-quality wines. And partial least squares discriminant analysis (PLS-DA) was applied to identify spoiled wines and good wines. Results showed that FTIR technique combined with chemometrics methods could effectively distinguish spoiled wines from fresh samples. The effect of classification at the wave band of 1 550-800 cm(-1) was the best. The recognition rate of SIMCA and PLSDA were respectively 94% and 100%. This study demonstrates that Fourier transform infrared spectroscopy is an effective tool for monitoring red wine's spoilage and provides theoretical support for developing early-warning equipments.

  15. Effects of storage temperature on the fungal and chemical spoilage of maize grains and flour

    International Nuclear Information System (INIS)

    Akhter, T.; Sattar, A.; Khan, I.; Ahmed, A.

    1989-01-01

    The chemical and fungal spoilage of maize grains and flour of Sarhad White and Sarhad Yellow varieties in relation to time temperature (10 C, 15 C, 20 C and room (30-56 C) storage period at 8-12 months was studied. The results showed that total fungal counts and percent infestation markedly increased with advanced storage and increased temperature. Percentage germination generally decreased during extended storage. Peroxide values of both the grain and flour increased with increasing temperature and storage time. At the end of one year storage the total fungal counts in the grain and flour of Sarhad White and Sarhad Yellow ranged 13.6x10/sup 12/ - 20.0x10/sup 13/ and Yellow ranged 17.1x10/sup 13/ - 22.1x10/sup 14/ respectively. germination and infestation percentage of the grains of Sarhad White and Sarhad Yellow ranged 76-78% and 96-99%. The peroxide value ranged 6.6-7.0 and 6.4-6.8 meg/Kg in the grain and flour of Sarhad White respectively after one year storage. There was more fungal infestation, fungal counts and peroxidation in the grain and flour Sarhad Yellow than that of Sarhad White. (author)

  16. Phytoalexins as possible controlling agents of microbial spoilage of irradiated fresh fruit and vegetables during storage

    International Nuclear Information System (INIS)

    El-Sayed, S.A.

    1978-01-01

    The decline in biogenerating capacity to form natural antibiotic compounds (phytoalexins), rishitin and lubimin in potato tubers and rishitin in tomatoes, after gamma irradiation seems to be the essence of the suppression of natural immunity exhibited by an increase in per cent of rotted tubers and fruits during storage. In vitro studies postulated that the rot-causing fungi Phytophthora infestans (Mond) De Bary, Alternaria solani (Ellis and Martin) James and Grout, Botrytis cinerea Persson., Fusarium oxysporum Syder and Hansen and Rhizopus stolonifer Ehrenberg were significantly controlled by the application of phytoalexins that had been initially formed by potato tubers (rishitin), tomato fruits (rishitin) and pepper fruits (capsidiol). In vivo studies revealed that post-irradiation treatment of potato tubers and tomato fruits with phytoalexins that had been produced by the same plant organ or by another of the same family seems to be experimentally feasible to reduce the radiation dose or increase the efficiency of irradiation in controlling microbial spoilage during storage of irradiated potatoes and tomatoes. (author)

  17. Control of chilled beef spoilage by combination of packaging and organic acid treatment

    Directory of Open Access Journals (Sweden)

    Sh Hanifian

    2007-11-01

    Full Text Available In this study, the  inhibitory  effect  of  lactic  acid  and  acetic  acid  spray  on  spoilage  of  packaged  fresh chilled  beef  was investigated. Meat from the chuck portion of 1 to 2 year old beef bulls was sprayed with 1% solution of lactic and acetic acids prior to packaging with polystyrene and stretch film. Meat  samples  were  kept  at 2- 4° C  and  the package were removed periodically in 2 day intervals from the refrigerating chamber and underwent microbial (total count, coliform cont and psychrophilic count, chemical (pH and TVN and organoleptic (drip, colour and odor examinations. The experiment was performed with 20 repetitions.  The results indicated that there was a significant increase in total, coliform and psychrophilic counts during an 8 day preservation period (P

  18. Stress resistance of biofilm and planktonic Lactobacillus plantarum subsp. plantarum JCM 1149

    OpenAIRE

    Kubota, Hiromi; Senda, Shouko; Tokuda, Hajime; Uchiyama, Hiroo; Nomura, Nobuhiko

    2009-01-01

    The purpose of this study was to investigate the change in resistance of biofilm and planktonic food spoilage lactic acid bacteria (LAB) to environmental stresses, which strongly inhibit bacterial growth and are important in food preservation or in disinfection. The stress responses of biofilm and planktonic cells of Lactobacillus plantarum subsp. plantarum JCM 1149, which was used as a model spoilage bacterium, in various organic acids (namely, acetic acid, citric acid, lactic acid, and mali...

  19. Preservation of food products by irradiation

    International Nuclear Information System (INIS)

    McGivney, W.T.

    1988-01-01

    The use of irradiation to preserve food has the potential to significantly enhance our capacity to maximize the quality and quantity of the food we consume. In a world in which distribution of food occurs across continents and in which malnourished populations are in dire need of basic food products, any safe, effective, and efficient means of preserving food is more than welcome. Irradiation, as a method for food preservation, has been studied for more than 30 years. This discussion focuses on this most recent method for the preservation of food with particular emphasis on its effects on the safety, nutritive, and aesthetic values of the food preserved by irradiation. The use of ionizing radiation as a method to preserve foods is one that has been demonstrated to be effective for a variety of food classes. Irradiation offers a means to decontaminate, disinfest, and retard the spoilage of the food supply. At the same time, it appears that the wholesomeness of these food products is maintained. Nutritive value can be sustained by use of effective doses of radiation. Concerns over the safety of irradiated food are rooted in questions regarding the potential induction of radioactivity, harmful radiolytic products, and pathogenic radiation-resistant or mutant strains of microorganisms. Research findings have allayed concerns over safety. However, more research is necessary to conclusively resolve these safety issues. Food irradiation is a promising technology that has and will contribute to our ability to feed the people of this world. This technology is but one of many available ways to preserve our greatest natural resource, the food supply. Enhancement of the ability to preserve food by irradiation will facilitate the distribution of food from fertile developed regions to the malnourished peoples of underdeveloped countries. 21 references

  20. Antimicrobial polyketide furanoterpenoids from seaweed-associated heterotrophic bacterium Bacillus subtilis MTCC 10403.

    Science.gov (United States)

    Chakraborty, Kajal; Thilakan, Bini; Raola, Vamshi Krishna

    2017-10-01

    Brown seaweed Anthophycus longifolius (Turner) Kützing (family Sargassaceae) associated heterotrophic bacterium Bacillus subtilis MTCC 10403 was found to be a potent isolate with broad range of antibacterial activity against important perceptive food pathogens Vibrio parahaemolyticus, V. vulnificus, and Aeromonas hydrophila. This bacterium was positive for polyketide synthetase gene (KC589397), and therefore, was selected to bioprospect specialized metabolites bearing polyketide backbone. Bioactivity-guided chromatographic fractionation of the ethyl acetate extract of the seaweed-associated bacterium segregated four homologous polyketide furanoterpenoids with potential antibacterial activities against clinically important pathogens. The minimum inhibitory concentration (MIC) assay showed that the referral antibiotics tetracycline and ampicillin were active at 25 μg/mL against the test pathogens, whereas the previously undescribed (4E)-methyl 13-((16-(furan-2-yl) ethyl)-octahydro-7-hydroxy-4-((E)-23-methylbut-21-enyl)-2H-chromen-6-yl)-4-methylpent-4-enoate (compound 1) and methyl 3-(hexahydro-9-((E)-3-methylpent-1-enyl)-4H-furo[3,2-g]isochromen-6-yl) propanoate (compound 3) displayed antibacterial activities against the test pathogens at a lesser concentration (MIC Polyketide synthase catalyzed putative biosynthetic mechanism additionally corroborated the structural ascriptions of the hitherto undescribed furanoterpenoids from seaweed-associated bacterial symbiont. The electronic and hydrophobic parameters appeared to hold a conspicuous part in directing the antibacterial properties of the compounds. Seaweed-associated B. subtilis MTCC 10403 demonstrated to represent a potential source of antimicrobial polyketides for pharmaceutical applications. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Unraveling microbial biofilms of importance for food microbiology.

    Science.gov (United States)

    Winkelströter, Lizziane Kretli; Teixeira, Fernanda Barbosa dos Reis; Silva, Eliane Pereira; Alves, Virgínia Farias; De Martinis, Elaine Cristina Pereira

    2014-07-01

    The presence of biofilms is a relevant risk factors in the food industry due to the potential contamination of food products with pathogenic and spoilage microorganisms. The majority of bacteria are able to adhere and to form biofilms, where they can persist and survive for days to weeks or even longer, depending on the microorganism and the environmental conditions. The biological cycle of biofilms includes several developmental phases such as: initial attachment, maturation, maintenance, and dispersal. Bacteria in biofilms are generally well protected against environmental stress, consequently, extremely difficult to eradicate and detect in food industry. In the present manuscript, some techniques and compounds used to control and to prevent the biofilm formation are presented and discussed. Moreover, a number of novel techniques have been recently employed to detect and evaluate bacteria attached to surfaces, including real-time polymerase chain reaction (PCR), DNA microarray and confocal laser scanning microscopy. Better knowledge on the architecture, physiology and molecular signaling in biofilms can contribute for preventing and controlling food-related spoilage and pathogenic bacteria. The present study highlights basic and applied concepts important for understanding the role of biofilms in bacterial survival, persistence and dissemination in food processing environments.

  2. Evaluation of the spoilage potential of bacteria isolated from spoiled cooked whole tropical shrimp (Penaeus vannamei) stored under modified atmosphere packaging.

    Science.gov (United States)

    Macé, Sabrina; Cardinal, Mireille; Jaffrès, Emmanuel; Cornet, Josiane; Lalanne, Valérie; Chevalier, Frédérique; Sérot, Thierry; Pilet, Marie-France; Dousset, Xavier; Joffraud, Jean-Jacques

    2014-06-01

    The spoilage potential of isolates belonging to five bacterial groups/species (Shewanella baltica, Carnobacterium maltaromaticum, Aeromonas salmonicida, Vibrio sp., "other Gamma-Proteobacteria" [containing one strain of Pseudoalteromonas sp. and one strain of Psychrobacter sp.]) isolated from spoiled cooked and whole tropical shrimp stored under modified atmosphere packaging (MAP) was evaluated by inoculation into ionized cooked and peeled tropical shrimp followed by storage for 32 days at 8 °C. Microbial growth and sensory changes were monitored during the storage period. The major spoilage bacterial isolate groups were C. maltaromaticum and S. baltica. In order to characterize their spoilage potential further and to study the effect of their interactions, each of these two specific spoilage organisms (SSO) and one mixed-culture, C. maltaromaticum/S. baltica, were tested using a combination of complementary methods: molecular (PCR-TTGE), sensory, chemical, and conventional microbiological analyses. It was concluded that, in the mixed-culture-inoculated samples, both species groups imposed their spoilage characteristics. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Bacterial diversity and spoilage-related microbiota associated with freshly prepared chicken products under aerobic conditions at 4°C.

    Science.gov (United States)

    Liang, Rongrong; Yu, Xiaoqiao; Wang, Renhuan; Luo, Xin; Mao, Yanwei; Zhu, Lixian; Zhang, Yimin

    2012-06-01

    This study analyzed the bacterial diversity and spoilage-related microbiota associated with freshly prepared chicken products stored aerobically at 4°C, using "bone and chicken string," a product popular in the People's Republic of China, as the study subject. Samples collected from three different factories were tray packaged with cling film and stored at 4°C. Bacterial diversity and dominant bacteria were analyzed using PCR amplification and denaturing gradient gel electrophoresis. Combined with selective cultivation of the dominant bacteria and correlation analysis, the dominant spoilage microbiota was determined. The results showed that bacterial diversity varied with different manufacturers. Such bacteria as Acinetobacter sp., Carnobacterium sp., Rahnella sp., Pseudomonas sp., Brochothrix sp., and Weissella sp. were detected in freshly prepared chicken products during storage. And Carnobacterium sp., Pseudomonas sp., and Brochothrix sp. bacteria were the common dominant spoilage bacteria groups in most freshly prepared chicken products from different factories. Carnobacterium was, for the first time, shown to be an important contributor to the spoilage-related microflora of freshly prepared chicken products stored aerobically under refrigeration. Our work shows the bacterial diversity and dominant spoilage microbiota of freshly prepared chicken products stored aerobically under refrigeration.

  4. Hydrogen Production by the Thermophilic Bacterium Thermotoga neapolitana

    Science.gov (United States)

    Pradhan, Nirakar; Dipasquale, Laura; d’Ippolito, Giuliana; Panico, Antonio; Lens, Piet N. L.; Esposito, Giovanni; Fontana, Angelo

    2015-01-01

    As the only fuel that is not chemically bound to carbon, hydrogen has gained interest as an energy carrier to face the current environmental issues of greenhouse gas emissions and to substitute the depleting non-renewable reserves. In the last years, there has been a significant increase in the number of publications about the bacterium Thermotoga neapolitana that is responsible for production yields of H2 that are among the highest achievements reported in the literature. Here we present an extensive overview of the most recent studies on this hyperthermophilic bacterium together with a critical discussion of the potential of fermentative production by this bacterium. The review article is organized into sections focused on biochemical, microbiological and technical issues, including the effect of substrate, reactor type, gas sparging, temperature, pH, hydraulic retention time and organic loading parameters on rate and yield of gas production. PMID:26053393

  5. Hydrogen Production by the Thermophilic Bacterium Thermotoga neapolitana

    Directory of Open Access Journals (Sweden)

    Nirakar Pradhan

    2015-06-01

    Full Text Available As the only fuel that is not chemically bound to carbon, hydrogen has gained interest as an energy carrier to face the current environmental issues of greenhouse gas emissions and to substitute the depleting non-renewable reserves. In the last years, there has been a significant increase in the number of publications about the bacterium Thermotoga neapolitana that is responsible for production yields of H2 that are among the highest achievements reported in the literature. Here we present an extensive overview of the most recent studies on this hyperthermophilic bacterium together with a critical discussion of the potential of fermentative production by this bacterium. The review article is organized into sections focused on biochemical, microbiological and technical issues, including the effect of substrate, reactor type, gas sparging, temperature, pH, hydraulic retention time and organic loading parameters on rate and yield of gas production.

  6. Inactivation of food-borne spoilage and pathogenic micro-organisms on the surface of a photoactive polymer.

    Science.gov (United States)

    Zerdin, Katherine; Scully, Andrew D

    2010-01-01

    The photodynamic action of a novel photoactive polymer comprising covalently bound anthraquinone (AQ) moieties was evaluated after developing a methodology to reliably immobilize viable micro-organisms onto polymer film surfaces. The survival of Escherichia coli, Bacillus cereus (vegetative cells and spores), Fusarium oxysporum and Saccharomyces cerevisiae microbes inoculated on the surface of inert polymeric substrates was assessed to determine the effect of inoculum composition, drying rate and exposure to ultraviolet (UV-A) radiation. Their survival was highly dependent on microbial genus, with E. coli consistently displaying markedly shorter survival times than the other microbes, and B. cereus spores being the most resistant. Inoculation of the microbes onto the surface of the photoactive polymer films, followed by exposure to UV-A radiation, dramatically accelerated the inactivation of all microbial types studied compared with their survival on the surface of inert polymer substrates. Simultaneous exposure to both oxygen and UV-A radiation is required to affect cell survival, which is consistent with this effect most likely originating from the photoinduced production of singlet oxygen by the photoactive polymer. These results provide further compelling evidence that singlet oxygen produced exogenously by this photoactive polymeric substrate can successfully inactivate a broad spectrum of microbes on the substrate's surface. © 2010 The Authors. Journal Compilation. The American Society of Photobiology.

  7. Standard Guide for Irradiation of Finfish and Aquatic Invertebrates Used as Food to Control Pathogens and Spoilage Microorganisms

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This guide outlines procedures and operations for the irradiation of raw, untreated, fresh (chilled), or frozen finfish and aquatic invertebrates, while ensuring that the irradiated product is safe and wholesome. 1.1.1 Aquatic invertebrates include molluscs, crustacea, echinoderms, etc. 1.1.1.1 Molluscs include bivalve shellfish, such as clams, mussels, and oysters; snails; and cephalopods, such as squid and octopus. 1.1.1.2 Crustacea include shellfish such as shrimp, lobster, crabs, prawns and crayfish. 1.1.1.3 Echinoderms include sea urchins and sea cucumbers. 1.2 This guide covers absorbed doses used to reduce the microbial and parasite populations in aquatic invertebrates and finfish. Such doses typically are below 10 kGy (1). 1.3 The use of reduced-oxygen packaging (vacuum or modified atmosphere, and including products packed in oil) with irradiated, raw product is not covered by this guide. The anaerobic environment created by reduced-oxygen packaging provides the potential for outgrowth o...

  8. Interactions between nitric oxide and ethylene in monomeric G-protein activation in relation to food spoilage

    DEFF Research Database (Denmark)

    Hall, M A; moshkov, moshkov; Novikova, G

    2014-01-01

    Climate change is likely to increase crop stress with negative impacts on yield and quality. Therefore, there is a need to develop our understanding of the key events which govern plant tolerance to stress. Intense research has identified key signalling cascades regulating stress tolerance and it...

  9. SUSCEPTIBILITY OF FOOD PRESERVATIVES ON MRSA AND MSSA ISOLATED FROM CLINICAL SAMPLES

    OpenAIRE

    Mamatha.C * and Dr. M. Thangavel

    2017-01-01

    Food preservatives are those substances which prevent spoilage caused by microbial or chemical causes. These preservatives may be natural or artificial. Natural preservatives are a hundred percent safe although the effectiveness lasts for shorter duration as compared with the artificial ones. Staphylococcus aureus was isolated from various clinical samples and confirmation was done using various biochemical tests. Antibiogram revealed the presence of 22 MRSA islolates and also the sensitivity...

  10. An automated ranking platform for machine learning regression models for meat spoilage prediction using multi-spectral imaging and metabolic profiling.

    Science.gov (United States)

    Estelles-Lopez, Lucia; Ropodi, Athina; Pavlidis, Dimitris; Fotopoulou, Jenny; Gkousari, Christina; Peyrodie, Audrey; Panagou, Efstathios; Nychas, George-John; Mohareb, Fady

    2017-09-01

    Over the past decade, analytical approaches based on vibrational spectroscopy, hyperspectral/multispectral imagining and biomimetic sensors started gaining popularity as rapid and efficient methods for assessing food quality, safety and authentication; as a sensible alternative to the expensive and time-consuming conventional microbiological techniques. Due to the multi-dimensional nature of the data generated from such analyses, the output needs to be coupled with a suitable statistical approach or machine-learning algorithms before the results can be interpreted. Choosing the optimum pattern recognition or machine learning approach for a given analytical platform is often challenging and involves a comparative analysis between various algorithms in order to achieve the best possible prediction accuracy. In this work, "MeatReg", a web-based application is presented, able to automate the procedure of identifying the best machine learning method for comparing data from several analytical techniques, to predict the counts of microorganisms responsible of meat spoilage regardless of the packaging system applied. In particularly up to 7 regression methods were applied and these are ordinary least squares regression, stepwise linear regression, partial least square regression, principal component regression, support vector regression, random forest and k-nearest neighbours. MeatReg" was tested with minced beef samples stored under aerobic and modified atmosphere packaging and analysed with electronic nose, HPLC, FT-IR, GC-MS and Multispectral imaging instrument. Population of total viable count, lactic acid bacteria, pseudomonads, Enterobacteriaceae and B. thermosphacta, were predicted. As a result, recommendations of which analytical platforms are suitable to predict each type of bacteria and which machine learning methods to use in each case were obtained. The developed system is accessible via the link: www.sorfml.com. Copyright © 2017 Elsevier Ltd. All rights

  11. Population heterogeneity and dynamics in starter culture and lag phase adaptation of the spoilage yeast Zygosaccharomyces bailii to weak acid preservatives.

    Science.gov (United States)

    Stratford, Malcolm; Steels, Hazel; Nebe-von-Caron, Gerhard; Avery, Simon V; Novodvorska, Michaela; Archer, David B

    2014-07-02

    The food spoilage yeast Zygosaccharomyces bailii shows great resistance to weak-acid preservatives, including sorbic acid (2, 4-hexadienoic acid). That extreme resistance was shown to be due to population heterogeneity, with a small sub-population of cells resistant to a variety of weak acids, probably caused by a lower internal pH reducing the uptake of all weak acids. In the present paper, it was found that resistant cells were extremely rare in exponential cultures, but increased by up to 8000-fold in stationary phase. Inoculation of media containing sorbic acid with a population of Z. bailii cells gave rise to what appeared to be a prolonged lag phase, suggesting adaptation to the conditions before the cells entered the period of exponential growth. However, the apparent lag phase caused by sorbic acid was largely due to the time required for the resistant sub-population to grow to detectable levels. The slow growth rate of the sub-population was identical to that of the final total population. The non-resistant bulk population remained viable for 3 days but had lost viability by 6 days and, during that time, there was no indication of any development of resistance in the bulk population. The sub-population growing in sorbic acid showed very high population diversity in colony size and internal pH. After removal of sorbic acid, the population rapidly reverted back to the normal, largely non-resistant, population distribution. The data presented suggest that a reevaluation of the lag phase in microbial batch culture is required, at least for the resistance of Z. bailii to sorbic acid. Furthermore, the significance of phenotypic diversity and heterogeneity in microbial populations is discussed more broadly with potential relevance to bacterial "persisters", natural selection and evolution. Copyright © 2014. Published by Elsevier B.V.

  12. Characterization of Osmotolerant Yeasts and Yeast-Like Molds from Apple Orchards and Apple Juice Processing Plants in China and Investigation of Their Spoilage Potential.

    Science.gov (United States)

    Wang, Huxuan; Hu, Zhongqiu; Long, Fangyu; Niu, Chen; Yuan, Yahong; Yue, Tianli

    2015-08-01

    Yeasts and yeast-like fungal isolates were recovered from apple orchards and apple juice processing plants located in the Shaanxi province of China. The strains were evaluated for osmotolerance by growing them in 50% (w/v) glucose. Of the strains tested, 66 were positive for osmotolerance and were subsequently identified by 26S or 5.8S-ITS ribosomal RNA (rRNA) gene sequencing. Physiological tests and RAPD-PCR analysis were performed to reveal the polymorphism of isolates belonging to the same species. Further, the spoilage potential of the 66 isolates was determining by evaluating their growth in 50% to 70% (w/v) glucose and measuring gas generation in 50% (w/v) glucose. Thirteen osmotolerant isolates representing 9 species were obtained from 10 apple orchards and 53 target isolates representing 19 species were recovered from 2 apple juice processing plants. In total, members of 14 genera and 23 species of osmotolerant isolates including yeast-like molds were recovered from all sources. The commonly recovered osmotolerant isolates belonged to Kluyveromyces marxianus, Hanseniaspora uvarum, Saccharomyces cerevisiae, Zygosaccharomyces rouxii, Candida tropicalis, and Pichia kudriavzevii. The polymorphism of isolates belonging to the same species was limited to 1 to 3 biotypes. The majority of species were capable of growing within a range of glucose concentration, similar to sugar concentrations found in apple juice products with a lag phase from 96 to 192 h. Overall, Z. rouxii was particularly the most tolerant to high glucose concentration with the shortest lag phase of 48 h in 70% (w/v) glucose and the fastest gas generation rate in 50% (w/v) glucose. © 2015 Institute of Food Technologists®

  13. Data supporting functional diversity of the marine bacterium Cobetia amphilecti KMM 296

    Directory of Open Access Journals (Sweden)

    Larissa Balabanova

    2016-09-01

    Full Text Available Data is presented in support of functionality of hyper-diverse protein families encoded by the Cobetia amphilecti KMM 296 (formerly Cobetia marina KMM 296 genome (“The genome of the marine bacterium Cobetia marina KMM 296 isolated from the mussel Crenomytilus grayanus (Dunker, 1853” [1] providing its nutritional versatility, adaptability and biocontrol that could be the basis of the marine bacterium evolutionary and application potential. Presented data include the information of growth and biofilm-forming properties of the food-associated isolates of Pseudomonas, Bacillus, Listeria, Salmonella and Staphylococcus under the conditions of their co-culturing with C. amphilecti KMM 296 to confirm its high inter-species communication and anti-microbial activity. Also included are the experiments on the crude petroleum consumption by C. amphilecti KMM 296 as the sole source of carbon in the presence of sulfate or nitrate to ensure its bioremediation capacity. The multifunctional C. amphilecti KMM 296 genome is a promising source for the beneficial psychrophilic enzymes and essential secondary metabolites.

  14. Evidence for a role of biosurfactants produced by Pseudomonas fluorescens in the spoilage of fresh aerobically stored chicken meat.

    Science.gov (United States)

    Mellor, Glen E; Bentley, Jessica A; Dykes, Gary A

    2011-08-01

    Fresh chicken meat is a fat-rich environment and we therefore hypothesised that production of biosurfactants to increase bioavailability of fats may represent one way in which spoilage bacteria might enhance the availability of nutrients. Numbers of Pseudomonas were determined on a total of 20 fresh and 20 spoiled chicken thighs with skin. A total of 400 randomly isolated Pseudomonas colonies from fresh (200) and spoiled (200) chicken were screened for the presence of biosurfactant production. Biosurfactant producing strains represented 5% and 72% of the Pseudomonas spp. isolates from fresh (mean count 2.3 log(10) cfu g(-1)) and spoiled (mean count 7.4 log(10) cfu g(-1)) chicken skin, respectively. Partially-purified biosurfactants derived from a subgroup of four Pseudomonasfluorescens strains obtained through the screening process were subsequently used to investigate the role that the addition of these compounds plays in the spoilage of aerobically stored chicken. Emulsification potential of the four selected biosurfactants was measured against a range of hydrocarbons and oils. All four biosurfactants displayed a greater ability to emulsify rendered chicken fat than hydrocarbons (paraffin liquid, toluene and hexane) and oils (canola, olive, sunflower and vegetable). Storage trials (4 °C) of chicken meat treated with the four selected biosurfactants revealed a significantly greater (P biosurfactant treated samples, as compared to untreated samples on each day (0, 1, 2, 3) of storage. For biosurfactant treated samples the greatest increase in total aerobic count (1.3-1.7 log(10) cfu g(-1)) occurred following one day of incubation. These results indicate that biosurfactants produced by Pseudomonas spp. may play an important role in the spoilage of aerobically stored chicken meat by making nutrients more freely available and providing strains producing them with a competitive advantage. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. The Department of the Army's food irradiation program - is it worth continuing

    International Nuclear Information System (INIS)

    1978-01-01

    In the last 25 years, the Department of Defense has spent $51 million on food irradiation research. The Army's food irradiation program is directed at using high doses of radiation to sterilize meats, thus preserving them from spoilage. The objective is to use irradiated meats in military rations. Despite the years of research, the Army has not yet convinced the Food and Drug Administration that irradiated meats are safe and nutritious. Legal, scientific, and economic barriers must be dealt with before radiation sterilized meats can be used in military rations

  16. Clostridium botulinum Toxin Production in Relation to Spoilage of Atlantic Salmon (Salmo salar) Packaged in Films of Varying Oxygen Permeabilities and with Different Atmospheres.

    Science.gov (United States)

    Erickson, Marilyn C; Ma, Li M; Doyle, Michael P

    2015-11-01

    Shelf life of fish packaged under modified atmosphere (MA) is extended, but within the United States, commercial application of MA with impermeable packaging films is restricted due to concerns that botulinum toxin production would precede spoilage when contaminated fish are held at abusive storage temperatures. Use of semipermeable packaging films has been advocated; however, previous studies are inconclusive in determining the oxygen transmission rate (OTR) of a film that is needed to achieve an acceptable margin of safety (i.e., toxin production occurs only after spoilage). This study was conducted to determine the influence of OTR (target OTRs of 3 to 15,000) on the development of spoilage volatiles and toxin in salmon inoculated with type E Clostridium botulinum and subjected to air, vacuum, or 75:25 CO2:N2 MA and storage temperatures of 4, 8, 12, or 16°C. The most dominant headspace volatile peak that was produced during spoilage of samples at 4, 8 or 12°C was a peak, having a Kovats retention index (KI) of 753, and at which external standards of 2- or 3-methyl 1-butanol also eluted. Under anaerobic conditions, both the aerobic microbial populations and the size of the KI 753 spoilage peak were less in inoculated samples compared with uninoculated samples. C. botulinum-inoculated samples that were stored at 12 or 16°C under conditions favorable for anaerobic growth were also characterized by a KI 688 peak. Using a previously developed model that related the percentage of elderly consumers who would prepare a sample having the KI 753 spoilage peak of a specific size, it was determined that for salmon packaged with 3 or 3,000 OTR films under any atmosphere and stored at 12 or 16°C, 2 to 61% of the consumers could potentially prepare toxin-contaminated samples. Hence, when abusive storage conditions are suspected, the fish should not be consumed.

  17. Microbiological changes, shelf life and identification of initial and spoilage microbiota of sea bream fillets stored under various conditions using 16S rRNA gene analysis.

    Science.gov (United States)

    Parlapani, Foteini F; Kormas, Konstantinos Ar; Boziaris, Ioannis S

    2015-09-01

    Sea bream fillets are one of the most important value-added products of the seafood market. Fresh seafood spoils mainly owing to bacterial action. In this study an exploration of initial and spoilage microbiota of sea bream fillets stored under air and commercial modified atmosphere packaging (MAP) at 0 and 5 °C was conducted by 16S rRNA gene sequence analysis of isolates grown on plates. Sensory evaluation and enumeration of total viable counts and spoilage microorganisms were also conducted to determine shelf life and bacterial growth respectively. Different temperatures and atmospheres affected growth and synthesis of spoilage microbiota as well as shelf life. Shelf life under air at 0 and 5 °C was 14 and 5 days respectively, while under MAP it was 20 and 8 days respectively. Initial microbiota were dominated by Pseudomonas fluorescens, Psychrobacter and Macrococcus caseolyticus. Different temperatures and atmospheres affected the synthesis of spoilage microbiota. At the end of shelf life, different phylotypes of Pseudomonas closely related to Pseudomonas fragi were found to dominate in most cases, while Pseudomonas veronii dominated in fillets under MAP at 0 °C. Furthermore, in fillets under MAP at 5 °C, new dominant species such as Carnobacterium maltaromaticum, Carnobacterium divergens and Vagococcus fluvialis were revealed. Different temperature and atmospheric conditions affected bacterial growth, shelf life and the synthesis of spoilage microbiota. Molecular identification revealed species and strains of microorganisms that have not been reported before for sea bream fillets stored under various conditions, thus providing valuable information regarding microbiological spoilage. © 2014 Society of Chemical Industry.

  18. Food irradiation and its biological effects

    International Nuclear Information System (INIS)

    Shah, Alok; Nanjappa, C.; Chauhan, O.P.

    2014-01-01

    Irradiation of foods drew attention mostly in 1960s for disinfestation of food grains, spices and sprout inhibition in mainly potato and onion. γ-irradiation at 0.25 to 1 kGy dosage levels are usually used for irradiating grains, legumes, spices and sprout-prone vegetables. Irradiation of foods with in permissible dosage levels of 0.25 to 5 kGy is usually considered fairly safe from human consumption point of view not withstanding usual health concerns about its usage in foods. Irradiation of foods, in mostly solid or semi-solid form, at 5 kGy levels of γ-irradiation can achieve radicidation or, radiation equivalent of pasteurization and, if γ-irradiation is used at 10 kGy, it can achieve radappertization or, radiation equivalent of thermal commercial sterilization. However, the food industry uses γ-irradiation at 0.25 to 2 kGy only for mostly disinfestation of food grains/legumes, spices, sprout inhibition in potato and onion and, for surface sanitation of frozen fish, poultry and meat. Exposure to irradiation creates free radicals in foods that are capable of destroying some of the spoilage and pathogenic microflora but the same can also damage vitamins and enzymes besides creating some new harmful new chemical species, called unique radiolytic products (URPs), by combining with certain chemicals that a food may be laced with (like pesticides/fungicides). Exposure to high-energy electron beams are also known to create deleterious biological effects which may even lead to detection of trace amounts of radioactivity in the food. Some possible causes delineated for such harmful biological effects of irradiation include: irradiation induced vitamin deficiencies, the inactivity of enzymes in the foods, DNA damage and toxic radiolytic products in the foods. Irradiation, a non-thermal food preservation technique, has a role in salvaging enormous post harvest losses (25-30%) in developing economies to increase the per capita availability of foods. (author)

  19. The physiology of the filamentous bacterium Microthrix parvicella

    NARCIS (Netherlands)

    Slijkhuis, H.

    1983-01-01

    A study has been made of the physiology of Microthrix parvicella. This filamentous bacterium often causes poor settleability of activated sludge in oxidation ditches supplied with domestic sewage. The organism was found to utilize only long chain fatty acids (preferably in

  20. Biosynthesis of silver nanoparticles by marine bacterium, Idiomarina ...

    Indian Academy of Sciences (India)

    Metal-tolerant microorganisms have been exploited in recent years to synthesize nanoparticles due to their potential to offer better size control through peptide binding and compartmentalization. In this paper, we report the intracellular synthesis of silver nanoparticles (SNPs) by the highly silver-tolerant marine bacterium, ...

  1. Control of magnetotactic bacterium in a micro-fabricated maze

    NARCIS (Netherlands)

    Khalil, I.S.M.; Pichel, Marc Philippe; Pichel, M.P.; Reefman, B.A.; Sardan Sukas, Ö.; Abelmann, Leon; Misra, Sarthak

    2013-01-01

    We demonstrate the closed-loop control of a magnetotactic bacterium (MTB), i.e., Magnetospirillum magnetotacticum, within a micro-fabricated maze using a magneticbased manipulation system. The effect of the channel wall on the motion of the MTB is experimentally analyzed. This analysis is done by

  2. Amylase activity of a yellow pigmented bacterium isolated from ...

    African Journals Online (AJOL)

    This study investigated the amylase activity of a yellow pigmented bacterium isolated from cassava wastes obtained from a dumpsite near a gari processing factory in Ibadan, Nigeria. Isolate was grown in nutrient broth containing 1% starch and then centrifuged at 5,000 rpm. Amylase activity was assayed using the DNSA ...

  3. Monitoring of a novel bacterium, Lactobacillus thermotolerans , in ...

    African Journals Online (AJOL)

    Abstract. We successfully established fluorescence in situ hybridization (FISH) method for specific detection and enumeration of a novel bacterium, Lactobacillus thermotolerans, in chicken feces. The specific FISH probes were designed based on the L. thermotolerans 16S rRNA gene sequences, and these sequences were ...

  4. Screening and characterization of petroleum-degrading bacterium ...

    African Journals Online (AJOL)

    Petroleum-degrading bacterium JY6 was isolated from petroleum-contaminated soils in DaQing oil field. It was identified as Bacillus cereus based on its morphological, physiological and biochemical characteristics, and analysis of its 16SrRNA gene. Biodegradation function of petroleum and oil degradation rates were ...

  5. Food safety concerns deriving from the use of silver based food packaging materials: a case study.

    Directory of Open Access Journals (Sweden)

    Alessandra ePezzuto

    2015-10-01

    Full Text Available The formulation of innovative packaging solutions, exerting a functional antimicrobial role in slowing down food spoilage, is expected to have a significant impact on the food industry, allowing both the maintenance of food safety criteria for longer periods and the reduction of food waste. Different materials are considered able to exert the required antimicrobial activity, among which are materials containing silver. However, challenges exist in the application of silver to food contact materials due to knowledge gaps in the production of ingredients, stability of delivery systems in food matrices and health risks caused by the same properties which also offer the benefits. Aims of the present study were to test the effectiveness and suitability of two packaging systems, one of which contained silver, for packaging and storing Stracchino cheese, a typical Italian fresh cheese, and to investigate if there was any potential for consumers to be exposed to silver, via migration from the packaging to the cheese. Results did not show any significant difference in the effectiveness of the packaging systems on packaged Stracchino cheese, excluding that the active packaging systems exerted an inhibitory effect on the growth of spoilage microorganisms. Moreover, silver migrated into the cheese matrix throughout the storage time (24 days. Silver levels in cheese finally exceeded the maximum established level for the migration of a non-authorised substance through a functional barrier (Commission Regulation (EC No. 450/2009. This result poses safety concerns and strongly suggests the need for more research aimed at better characterizing the new packaging materials in terms of their potential impacts on human health and the environment.

  6. Identification of lactic acid bacteria from spoilage associations of cooked and brined shrimps stored under modified atmosphere between 0 degrees C and 25 degrees C

    DEFF Research Database (Denmark)

    Dalgaard, Paw; Vancanneyt, M.; Vilalta, N.E.

    2003-01-01

    MAP shrimps were characterized by phenotypic tests and identified as lactic acid bacteria (78 isolates), other Gram-positive bacteria (13 isolates) and Gram-negative bacteria (11 isolates). A selection of 48 LAB isolates were further characterized and identified by phenotypic tests and SDS-PAGE...... the dominant parts of spoilage associations of cooked and brined MAP shrimps stored at high and low temperatures, respectively. Significance and Impact of the Study: The SDS-PAGE technique and simple biochemical keys allowed the majority of LAB isolates from spoilage associations of cooked and brined MAP...

  7. Effect of weak acid preservatives on growth of bakery product spoilage fungi at different water activities and pH values

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Nielsen, Per Væggemose

    2004-01-01

    Inhibition of spoilage organisms from bakery products by weak acid preservatives in concentrations of 0%, 0.003%, 0.03% and 0.3% (w/v) was investigated experimentally on a substrate media with water activity (a(w)) and pH ranging from sourdough-fermented acidic rye bread to alkaline intermediate...... activity levels as well as higher pH values decreased spoilage-free times of the fungi. The preservative calcium propionate was less effective than potassium sorbate and sodium benzoate....

  8. Effect of weak acid preservatives on growth of bakery product spoilage fungi at different water activities and pH values

    DEFF Research Database (Denmark)

    Suhr, Karin Isabel; Nielsen, Per Væggemose

    2004-01-01

    Inhibition of spoilage organisms from bakery products by weak acid preservatives in concentrations of 0%, 0.003%, 0.03% and 0.3% (w/v) was investigated experimentally on a substrate media with water activity (a(w)) and pH ranging from sourdough-fermented acidic rye bread to alkaline intermediate...... of bakery products was conducted using calcium propionate, potassium sorbate and sodium benzoate. The obtained data was modelled using survival analysis to determine 'spoilage-free time' for the fungi. At the low a(w) level (0.80) only Eurotium species grew within the test period of 30 days. Higher water...

  9. Food hygienics

    International Nuclear Information System (INIS)

    Ryu, Yeong Gyun; Lee, Gwang Bae; Lee, Han Gi; Kim, Se Yeol

    1993-01-01

    This book deals with food hygienics with eighteen chapters, which mention introduction on purpose of food hygienics, administration of food hygienics, food and microscopic organism, sanitary zoology, food poisoning, food poisoning by poisonous substance, chronic poisoning by microscopic organism, food and epidemic control , control of parasitic disease, milk hygiene meat hygiene, an egg and seafood hygiene, food deterioration and preservation, food additives, food container and field hygiene, food facilities hygiene, food hygiene and environmental pollution and food sanitation inspection.

  10. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America

    Science.gov (United States)

    Eads, David A.; Biggins, Dean E.

    2015-01-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research.

  11. Plague bacterium as a transformer species in prairie dogs and the grasslands of western North America.

    Science.gov (United States)

    Eads, David A; Biggins, Dean E

    2015-08-01

    Invasive transformer species change the character, condition, form, or nature of ecosystems and deserve considerable attention from conservation scientists. We applied the transformer species concept to the plague bacterium Yersinia pestis in western North America, where the pathogen was introduced around 1900. Y. pestis transforms grassland ecosystems by severely depleting the abundance of prairie dogs (Cynomys spp.) and thereby causing declines in native species abundance and diversity, including threatened and endangered species; altering food web connections; altering the import and export of nutrients; causing a loss of ecosystem resilience to encroaching invasive plants; and modifying prairie dog burrows. Y. pestis poses an important challenge to conservation biologists because it causes trophic-level perturbations that affect the stability of ecosystems. Unfortunately, understanding of the effects of Y. pestis on ecosystems is rudimentary, highlighting an acute need for continued research. © 2015 Society for Conservation Biology.

  12. Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

    International Nuclear Information System (INIS)

    Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

    2008-04-01

    This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions

  13. Preliminary Studies for the Application of Irradiated-Food to Food Service Industry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-Woon; Byun, Myung-Woo; Kim, Jae-Hun; Choi, Jong-Il; Song, Beom-Seok; Kim, Dong-Ho; Seo, Min-Won

    2008-04-15

    This study is to investigate ways to improve the marketability of irradiated food materials, through examining reports on toxicological safety and public acceptance of irradiated food materials. Many studies have reaffirmed the mutagenic, genotoxicological, microbiological, and nutritional safety of food irradiation, and consider it an important tool to reduce loss of food due to spoilage and pests. Although food irradiation could provide an opportunity to replace certain pesticides and food additives, there is ambivalence among consumers on whether or not the technology provides a real benefit. An easy and inexpensive tool to identify irradiation trace residue in foods, public trust building in industry through educating consumers with the benefit and uses of irradiation process are thought to be key elements for a successful market for irradiated food. Gamma irradiation at 50 kGy was applied to food materials for institutional food-service to evaluate their possible genotoxicity. The genotoxicity of 12 kinds of food materials irradiated at 50 kGy for institutional food-service was evaluated by Salmonella typhimurium reversion assay, chromosomal aberration test and in vivo micronucleus assay. The results of bacterial reversion assay with S. typhimurium TA98, TA100, TA1535 and TA1537 were negative in the 12 kinds of food materials irradiated at 50 kGy. No mutagenicity was detected in the assay with and without metabolic activation. In chromosomal aberration tests with CHL cells and in vivo mouse micronucleus assay, no significant difference in the incidences of chromosomal aberration and micronuclei was observed between non-irradiated and 50 kGy-irradiated food materials. These results indicate that food materials irradiated at 50 kGy for institutional food-service did not show any genotoxic effects under these experimental conditions.

  14. Processing- and product-related causes for food waste and implications for the food supply chain.

    Science.gov (United States)

    Raak, Norbert; Symmank, Claudia; Zahn, Susann; Aschemann-Witzel, Jessica; Rohm, Harald

    2017-03-01

    Reducing food waste is one of the prominent goals in the current research, which has also been set by the United Nations to achieve a more sustainable world by 2030. Given that previous studies mainly examined causes for food waste generation related to consumers, e.g., expectations regarding quality or uncertainties about edibility, this review aims at providing an overview on losses in the food industry, as well as on natural mechanisms by which impeccable food items are converted into an undesired state. For this, scientific literature was reviewed based on a keyword search, and information not covered was gathered by conducting expert interviews with representatives from 13 German food processing companies. From the available literature, three main areas of food waste generation were identified and discussed: product deterioration and spoilage during logistical operations, by-products from food processing, and consumer perception of quality and safety. In addition, expert interviews revealed causes for food waste in the processing sector, which were categorised as follows: losses resulting from processing operations and quality assurance, and products not fulfilling quality demands from trade. The interviewees explained a number of strategies to minimise food losses, starting with alternative tradeways for second choice items, and ending with emergency power supplies to compensate for power blackouts. It became clear that the concepts are not universally applicable for each company, but the overview provided in the present study may support researchers in finding appropriate solutions for individual cases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Food and grain preservation through irradiation. January 1970-January 1988 (citations from the NTIS data base). Report for January 1970-January 1988

    International Nuclear Information System (INIS)

    1988-01-01

    This bibliography contains citations concerning the principles, methods, and results of using ionized irradiation to preserve grains and foods through reduction of spoilage and infestation. The citations cover irradiation chemistry as it affects food wholesomeness, nutrition, and changes in food value. Irradiation methods include sources of irradiation, primarily gamma rays, and dosage for specific foods. Many articles reference public health and safety, studies of effect of irradiated food on laboratory animals, and associated standards and legislation. (This updated bibliography contains 325 citations, 35 of which are new entries to the previous edition.)

  16. Characterization of the Biodiversity of the Spoilage Microbiota in Chicken Meat Using Next Generation Sequencing and Culture Dependent Approach

    Science.gov (United States)

    2017-01-01

    This study investigated the psychrotrophic bacteria isolated from chicken meat to characterize their microbial composition during refrigerated storage. The bacterial community was identified by the Illumina MiSeq method based on bacterial DNA extracted from spoiled chicken meat. Molecular identification of the isolated psychrotrophic bacteria was carried out using 16S rDNA sequencing and their putrefactive potential was investigated by the growth at low temperature as well as their proteolytic activities in chicken meat. From the Illumina sequencing, a total of 187,671 reads were obtained from 12 chicken samples. Regardless of the type of chicken meat (i.e., whole meat and chicken breast) and storage temperatures (4°C and 10°C), Pseudomonas weihenstephanensis and Pseudomonas congelans were the most prominent bacterial species. Serratia spp. and Acinetobacter spp. were prominent in chicken breast and whole chicken meat, respectively. The 118 isolated strains of psychrotrophic bacteria comprised Pseudomonas spp. (58.48%), Serratia spp. (10.17%), and Morganella spp. (6.78%). All isolates grew well at 10°C and they induced different proteolytic activities depending on the species and strains. Parallel analysis of the next generation sequencing and culture dependent approach provides in-depth information on the biodiversity of the spoilage microbiota in chicken meat. Further study is needed to develop better preservation methods against these spoilage bacteria. PMID:28943766

  17. High pressure treatment changes spoilage characteristics and shelf life of Pacific oysters ( Crassostrea gigas) during refrigerated storage

    Science.gov (United States)

    Cao, Rong; Zhao, Ling; Liu, Qi

    2017-04-01

    The effects of high pressure (HP) treatment on spoilage characteristic and shelf life extension of Pacific oysters ( Crassostrea gigas) during refrigerated storage were studied. Results showed that HP treatment of 275 MPa for 3 min or 300 MPa for 2 min could achieve 100% full release of oyster adductor muscle, pressures higher than 350 MPa caused excessive release as the shells of oysters were broken, thus use of higher pressures should be cautious in oyster processing industry because of its adverse impact on the appearance of shells. HP treatment (300 MPa, 2 min) was proper for the shucking of Pacific oyster ( Crassostrea gigas) in China. This treatment caused no organoleptic disadvantage. Moreover, HP treatment resulted in obvious differences in biochemical spoilage indicators (pH, TVB-N and TBARS) changes and volatile compounds profile determined by electronic nose during storage. HP treatment (300 MPa, 2 min) also led to a reduction of aerobic bacterial count (APC) by 1.27 log cycles. Furthermore, the APC values of oysters treated by HP were always lower than those of the control samples during storage. Based on the organoleptic, biochemical and microbiological indicators, shelf life of 6-8 d for control and 12 d for HP-treated oysters could be expected. HP treatment showed great potential in oyster processing and preservation.

  18. Fast Classification of Meat Spoilage Markers Using Nanostructured ZnO Thin Films and Unsupervised Feature Learning

    Directory of Open Access Journals (Sweden)

    John Bosco Balaguru Rayappan

    2013-01-01

    Full Text Available This paper investigates a rapid and accurate detection system for spoilage in meat. We use unsupervised feature learning techniques (stacked restricted Boltzmann machines and auto-encoders that consider only the transient response from undoped zinc oxide, manganese-doped zinc oxide, and fluorine-doped zinc oxide in order to classify three categories: the type of thin film that is used, the type of gas, and the approximate ppm-level of the gas. These models mainly offer the advantage that features are learned from data instead of being hand-designed. We compare our results to a feature-based approach using samples with various ppm level of ethanol and trimethylamine (TMA that are good markers for meat spoilage. The result is that deep networks give a better and faster classification than the feature-based approach, and we thus conclude that the fine-tuning of our deep models are more efficient for this kind of multi-label classification task.

  19. Heat inactivation of wine spoilage yeast Dekkera bruxellensis by hot water treatment.

    Science.gov (United States)

    Fabrizio, V; Vigentini, I; Parisi, N; Picozzi, C; Compagno, C; Foschino, R

    2015-08-01

    Cell suspensions of four Dekkera bruxellensis strains (CBS 2499, CBS 2797, CBS 4459 and CBS 4601) were subjected to heat treatment in deionized water at four different temperatures (55·0, 57·5, 60·0 and 62·5°C) to investigate their thermal resistance. The decimal reduction times at a specific temperature were calculated from the resulting inactivation curves: the D-values at 55·0°C ranged from 63 to 79·4 s, at 57·5°C from 39·6 to 46·1 s, at 60·0°C from 19·5 to 20·7 s, at 62·5°C from 10·2 to 13·7 s. The z-values were between 9·2 and 10·2°C, confirming that heat resistance is a strain-dependent character. A protocol for the sanitization of 225 l casks by immersion in hot water was set up and applied to contaminated 3-year-old barrels. The heat penetration through the staves was evaluated for each investigated temperature by positioning a thermal probe at 8 mm deep. A treatment at 60°C for an exposure time of 19 min allowed to eliminate the yeast populations up to a log count reduction of 8. Brettanomyces/Dekkera bruxellensis is the main yeast involved in red wine spoilage that occurs during ageing in barrel, generating considerable economic losses. Current sanitization protocols, performed using different chemicals, are ineffective due to the porous nature of the wood. The thermal inactivation of D. bruxellensis cells by hot water treatment proves to be efficacious and easy to perform, provided that the holding time at the killing temperature takes into account the filling time of the vessel and the time for the heat penetration into the wood structure. © 2015 The Society for Applied Microbiology.

  20. Reducing the bloater spoilage incidence in fermented green olives during storage

    Directory of Open Access Journals (Sweden)

    Brito, D.

    2002-09-01

    Full Text Available Fermented green olives of the variety “Picholine” were brined in 5% NaCl solutions, which were adjusted to pH 4.00 and 5.00 with lactic acid. Potassium sorbate was added to the brine at 0.05 % and the assays were inoculated with Lactobacillus plantarum strain I159, and Pichia anomala strains S18 from our collection. The pH values and microbial counts including Gram negative bacteria, yeasts and moulds, and lactic acid bacteria were followed during 6 months of storage. Results showed that even if the olives were inoculated with a high gas producing yeast (P. anomala S18, the attack of the fruits by the “bloater” spoilage was drastically reduced in the assays adjusted to pH4, added with potassium sorbate and inoculated with L. plantarum, without affecting the organoleptic characteristics of the product.Aceitunas verdes fermentadas de la variedad Picholine fueron colocadas en soluciones de salmuera al 5% en NaCl, ajustando el pH a 4,00 y 5,00 con ácido láctico. Se agregó sorbato potásico a la salmuera a una concentración del 0,05% y las muestras se inocularon con cepas de Lactobacllius plantarum I159 y Pichia anomala S18 de nuestra procedencia. Los valores del pH y el recuento microbiano incluyendo a las bacterias Gram-negativas, levaduras y mohos y bacterias del ácido láctico se siguieron durante los seis meses de almacenamiento. Los resultados mostraron que incluso inoculando las aceitunas con la levadura (P. anomala S18, productora de alta cantidad de gas, el ataque de los frutos por el alambrado se redujo drásticamente en las muestras ajustadas a pH4, a las que se añadió sorbato potásico e inoculó con Lactobacllius plantarum, sin verse afectadas las características organolépticas del producto.

  1. Electronic Nose for Microbiological Quality Control of Food Products

    Directory of Open Access Journals (Sweden)

    M. Falasconi

    2012-01-01

    Full Text Available Electronic noses (ENs have recently emerged as valuable candidates in various areas of food quality control and traceability, including microbial contamination diagnosis. In this paper, the EN technology for microbiological screening of food products is reviewed. Four paradigmatic and diverse case studies are presented: (a Alicyclobacillus spp. spoilage of fruit juices, (b early detection of microbial contamination in processed tomatoes, (c screening of fungal and fumonisin contamination of maize grains, and (d fungal contamination on green coffee beans. Despite many successful results, the high intrinsic variability of food samples together with persisting limits of the sensor technology still impairs ENs trustful applications at the industrial scale. Both advantages and drawbacks of sensor technology in food quality control are discussed. Finally, recent trends and future directions are illustrated.

  2. Implementation of classical, molecular biological and immunoenzymatic methods in isolation and detection of Listeria monocytogenes in food

    Directory of Open Access Journals (Sweden)

    Lakićević Brankica Z.

    2014-01-01

    Full Text Available Food borne pathogens and spoilage bacteria are influencing the safety and quality of food and animal feed and can result in serious adverse effects to human and animal health as well as to the food quality. Consequently, microbiological quality control in the food industry has become the priority of the food producers and it aims towards minimizing the risks related to food pathogens and spoilage bacteria. One of the most important pathogens in the food industry is Listeria monocytogenes. Listeriosis has a significant public health and economic impact because of its high hospitalization and mortality rate. Most people infected with Listeria are hospitalized and mortality is approximately 30 %. Therefore it is necessary to undertake efficient control measures, especially concerning the necessity of a rapid and accurate detection of this pathogen in the food industry as well as in retail food samples. Recently used conventional methods are often time consuming and require intensive work. However, obtained results can often be false considering the presence of viable but not cultivable microorganisms. Advances in biotechnology and bioinformatics have resulted in the development of novel testing technologies that enable tracking, more reliable and faster detection of food pathogens. Furthermore, molecular-biology methods, although still not applied routinely in everyday practice, are the promising alternative which can replace current reference methods in this area.

  3. An introduction to the irradiation processing of foods

    International Nuclear Information System (INIS)

    Hackwood, S.

    1991-01-01

    The food industry has used a variety of methods over the years to preserve or extend the shelf life of food. These have included cooking, packaging, smoking, chilling, freezing, dehydrating and using chemical additives. More recently, ionising radiation has been used to extend the storage life of foods. More research has been focussed on the effects of irradiation on foods than has been directed at any other form of food processing. This research has spanned 40 years and has been carried out in many countries. Food irradiation can be used to: (a) inhibit the sprouting of vegetables; (b) delay the ripening of fruits; (c) kill insect pests in fruit, grains or spices; (d) reduce or eliminate food spoilage organisms; (e) reduce food poisoning bacteria on some meats and sea food products. This chapter includes sections on the historical background; general aspects of radiation; scientific, technological, microbiological and toxicological aspects of food irradiation; nutritional aspects of food irradiation; consumer attitudes; current status and legislation; labelling. It concludes that the relatively new process of preserving food by irradiation compliments rather than competes with the presently available traditional methods. (author)

  4. The intertwine of nanotechnology with the food industry.

    Science.gov (United States)

    Hamad, Alshammari Fanar; Han, Jong-Hun; Kim, Byung-Chun; Rather, Irfan A

    2018-01-01

    The past decade has proven the competence of nanotechnology in almost all known fields. The evolution of nanotechnology today in the area of the food industry has been largely and has had a lot of contribution in the food processing, food package, and food preservation. The increasing global human population has come with growing population to be fed, and food production is not adjusted to at par with the growing population. This mismatch has shown the real essence of food preservation so that food products can reach to people on a global scale. The introduction of nanotechnology in the food industry has made it easy to transport foods to different parts of the world by extending the shelf-life of most food products. Even with this beneficial aspect of nanotechnology, it has not been proven an entire full-proof measure, and the field is still open to changing technology. It suffices to note that nanotechnology has to a big extent succeed in curbing the extent of food wastage due to food spoilage by the microbial infestation. Nanotechnology has focused on fresh foods, ensuring a healthier food by employing nano-delivery systems in the process. The delivery systems are the ones, which carries the food supplements. However, these are certain sets of regulations that must be followed to tame or control the health related risks of nanotechnology in food industries. This paper outlines the role of nanotechnology at different levels of the food industry including, packaging of food, processing of food and the various preservation techniques all aiming to increase the shelf life of the food products.

  5. Use of Cymbopogon citratus essential oil in food preservation: Recent advances and future perspectives.

    Science.gov (United States)

    Ekpenyong, Christopher E; Akpan, Ernest E

    2017-08-13

    The economic burdens and health implications of food spoilage are increasing. Contamination of food sources by fungi, bacteria, yeast, nematodes, insects, and rodents remains a major public health concern. Research has focused on developing safer natural products and innovations to meet consumers' acceptance as alternatives to synthetic food preservatives. Many recent novel preservative techniques and applications of both natural and synthetic origin continue to proliferate in food and chemical industries. In particular, some essential oils of plant origin are potent food preservatives and are thus attractive alternatives to synthetic preservatives. This paper provides an overview of recent advances and future prospects in assessing the efficacy of the use of Cymbopogon citratus (lemongrass) essential oil in food preservation. The possible mechanisms of action and toxicological profile as well as evidence for or against the use of this essential oil as an alternative to synthetic food preservatives in domestic and industrial applications are discussed.

  6. Nanotechnology to the rescue: using nano-enabled approaches in microbiological food safety and quality.

    Science.gov (United States)

    Eleftheriadou, Mary; Pyrgiotakis, Georgios; Demokritou, Philip

    2017-04-01

    Food safety and quality assurance is entering a new era. Interventions along the food supply chain must become more efficient in safeguarding public health and the environment and must address numerous challenges and new consumption trends. Current methods of microbial control to assure the safety of food and minimize microbial spoilage have each shown inefficiencies. Nanotechnology is a rapidly expanding area in the agri/feed/food sector. Nano-enabled approaches such as antimicrobial food-contact surfaces/packaging, nano-enabled sensors for rapid pathogen/contaminant detection and nano-delivered biocidal methods, currently on the market or at a developmental stage, show great potential for the food industry. Concerns on potential risks to human health and the environment posed by use of engineered nanomaterials (ENMs) in food applications must, however, be adequately evaluated at the developmental stage to ensure consumer's acceptance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Food irradiation: A technique for preserving and improving the safety of food

    International Nuclear Information System (INIS)

    1992-01-01

    Processing of food with low levels of radiation has the potential to contribute to reducing both spoilage of food during storage - a particular problem in developing countries - and the high incidence of food-borne disease currently seen in all countries. Approval has been granted for the treatment of more than 30 products with radiation in over 30 countries but, in general , governments have been slow to authorize the use of this new technique. One reason for this slowness is a lack of understanding of what food irradiation entails. This book aims to increase understanding by providing information on the process of food irradiation in simple, non-technical language. It describes the effects that irradiation has on food , and the plant and equipment that are necessary to carry it out safely. The legislation and control mechanisms required to ensure the safety of food irradiation facilities are also discussed. Education is seen as the key to gaining the confidence of the consumers in the safety of irradiated food, and to promoting understanding of the benefits that irradiation can provide

  8. Food irradiation: A technique for preserving and improving the safety of food

    International Nuclear Information System (INIS)

    1988-01-01

    Processing of food with low levels of radiation has the potential to contribute to reducing both spoilage of food during storage - a particular problem in developing countries - and the high incidence of food-borne disease currently seen in all countries. Approval has been granted for the treatment of more than 30 products with radiation in over 30 countries but, in general, governments have been slow to authorize the use of this new technique. One reason for this slowness is a lack of understanding of what food irradiation entails. This book aims to increase understanding by providing information on the process of food irradiation in simple, non-technical language. It describes the effects that irradiation has on food, and the plant and equipment that are necessary to carry it out safely. The legislation and control mechanisms required to ensure the safety of food irradiation facilities are also discussed. Education is seen as the key to gaining the confidence of the consumers in the safety of irradiated food, and to promoting understanding of the benefits that irradiation can provide

  9. Indigenous and spoilage microbiota of farmed sea bream stored in ice identified by phenotypic and 16S rRNA gene analysis.

    Science.gov (United States)

    Parlapani, F F; Meziti, A; Kormas, K Ar; Boziaris, I S

    2013-02-01

    Investigation of the initial and spoilage microbial diversity of iced stored sea bream was carried out. Culture dependent methods were used for bacterial enumeration and phenotypic identification of bacterial isolates, while culture independent methods, using bacterial 16S rRNA gene amplification, cloning and sequencing of DNA extracted directly from the flesh were also employed. The culture dependent approach revealed that the initial microbiota was dominated by Acinetobacter, Shewanella, Pseudomonas and Flavobacterium, while at the end of shelf-life determined by sensory analysis (16 days), the predominant microbiota was Pseudomonas and Shewanella. Culture independent approach showed that initially the sea bream flesh was strongly dominated by Acinetobacter, while Pseudomonas, Aeromonas salmonicida and Shewanella were the predominant phylotypes at the end of shelf-life. Initial and spoilage microbiota comprised of phylotypes previously identified by others using traditional or molecular techniques. However, Aeromonas has not been reported as part of the dominant microbiota of sea bream at the time of spoilage. Combination of classical and molecular methodologies better reveals the microbiota during storage by revealing bacteria that escape standard approaches and, thus, provides valuable complementary information regarding microbiological spoilage. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Biosorption of heavy metals by a marine bacterium

    International Nuclear Information System (INIS)

    Iyer, Anita; Mody, Kalpana; Jha, Bhavanath

    2005-01-01

    Heavy metal chelation property of exopolysaccharide produced by Enterobacter cloaceae, a marine bacterium, isolated from the West Coast of India, is reported in this paper. The exopolysaccharide demonstrated excellent chelating properties with respect to cadmium (65%) followed by copper (20%) and cobalt (8%) at 100 mg/l heavy metal concentration. However, it could not chelate mercury. A comparative study of the percentage biosorption of the above mentioned metals is presented here

  11. Genome Sequence of the Milbemycin-Producing Bacterium Streptomyces bingchenggensis▿

    OpenAIRE

    Wang, Xiang-Jing; Yan, Yi-Jun; Zhang, Bo; An, Jing; Wang, Ji-Jia; Tian, Jun; Jiang, Ling; Chen, Yi-Hua; Huang, Sheng-Xiong; Yin, Min; Zhang, Ji; Gao, Ai-Li; Liu, Chong-Xi; Zhu, Zhao-Xiang; Xiang, Wen-Sheng

    2010-01-01

    Streptomyces bingchenggensis is a soil-dwelling bacterium producing the commercially important anthelmintic macrolide milbemycins. Besides milbemycins, the insecticidal polyether antibiotic nanchangmycin and some other antibiotics have also been isolated from this strain. Here we report the complete genome sequence of S. bingchenggensis. The availability of the genome sequence of S. bingchenggensis should enable us to understand the biosynthesis of these structurally intricate antibiotics bet...

  12. Initiation of chromosomal replication in predatory bacterium Bdellovibrio bacteriovorus

    Directory of Open Access Journals (Sweden)

    Lukasz Makowski

    2016-11-01

    Full Text Available Bdellovibrio bacteriovorus is a small Gram-negative predatory bacterium that attacks other Gram-negative bacteria, including many animal, human, and plant pathogens. This bacterium exhibits a peculiar biphasic life cycle during which two different types of cells are produced: non-replicating highly motile cells (the free-living phase and replicating cells (the intracellular-growth phase. The process of chromosomal replication in B. bacteriovorus must therefore be temporally and spatially regulated to ensure that it is coordinated with cell differentiation and cell cycle progression. Recently, B. bacteriovorus has received considerable research interest due to its intriguing life cycle and great potential as a prospective antimicrobial agent. Although we know that chromosomal replication in bacteria is mainly regulated at the initiation step, no data exists about this process in B. bacteriovorus. We report the first characterization of key elements of initiation of chromosomal replication – DnaA protein and oriC region from the predatory bacterium, B. bacteriovorus. In vitro studies using different approaches demonstrate that the B. bacteriovorus oriC (BdoriC is specifically bound and unwound by the DnaA protein. Sequence comparison of the DnaA-binding sites enabled us to propose a consensus sequence for the B. bacteriovorus DnaA box (5’-NN(A/TTCCACA-3’. Surprisingly, in vitro analysis revealed that BdoriC is also bound and unwound by the host DnaA proteins (relatively distantly related from B. bacteriovorus. We compared the architecture of the DnaA–oriC complexes (orisomes in homologous (oriC and DnaA from B. bacteriovorus and heterologous (BdoriC and DnaA from prey, E. coli or P. aeruginosa systems. This work provides important new entry points toward improving our understanding of the initiation of chromosomal replication in this predatory bacterium.

  13. Irradiation processing of food items for exports

    International Nuclear Information System (INIS)

    Sareen, Shashi

    1998-01-01

    Globalization has led to rapid increases in international food trade. About 460 million metric tonnes of foodstuffs are traded annually of a value to the order of 300 billion US dollar. With such high trade figures, it is imperative to provide safe and nutritious foods to consumers and to minimize food losses due to spoilage. Food irradiation is a technology which has been under study and debate since fifties for the purpose of food preservation. This technology has been extensively reviewed and studied at international levels and by several countries and on the basis of these, a number of countries have permitted the use of irradiation for specified foods and are also applying it on commercial scale. In this paper, a review of the status and importance of this technology has been brought out to include the application of the technology and its perceived benefits, acceptance of the technology at the international level and by different countries including the scenario in India, the various types of concerns expressed by Governments as well as consumers and specific areas with regard to exports for which the technology would be beneficial. (author)

  14. Applicability of a microbial Time Temperature Indicator (TTI) for monitoring spoilage of modified atmosphere packed minced meat.

    Science.gov (United States)

    Vaikousi, Hariklia; Biliaderis, Costas G; Koutsoumanis, Konstantinos P

    2009-08-15

    The applicability of a microbial Time Temperature Indicator (TTI) prototype, based on the growth and metabolic activity of a Lactobacillus sakei strain developed in a previous study, in monitoring quality of modified atmosphere packed (MAP) minced beef was evaluated at conditions simulating the chill chain. At all storage temperatures examined (0, 5, 10, 15 degrees C), the results showed that lactic acid bacteria (LAB) were the dominant bacteria and can be used as a good spoilage index of MAP minced beef. The end of product's shelf life as revealed by the sensory evaluation coincided with a LAB population level of 7 log(10) CFU/g. For all temperatures tested, the growth of L. sakei in the TTI resembled closely the growth of LAB in the meat product, with similar temperature dependence of the micro(max) and thus similar activation energy values calculated as 111.90 and 106.90 kJ/mol, for the two systems, respectively. In addition, the end point of TTI colour change coincided with the time of sensory rejection point of the beef product during its storage under isothermal chilled temperature conditions. The estimated activation energy, E(alpha), values obtained for parameters related to the response of DeltaE (total colour change of the TTI) describing the kinetics of colour change of the TTI during isothermal storage (i.e. the maximum specific rate of DeltaEpsilon evolution curve, micro(DeltaEpsilon), and also the reciprocal of t(i), time at which half of the maximum DeltaEpsilon is reached), were 112.77 and 127.28 kJ/mol, respectively. Finally, the application of the microbial TTI in monitoring the quality deterioration of MAP minced beef due to spoilage was further evaluated under dynamic conditions of storage, using two separate low temperature periodic changing scenarios, resembling the actual conditions occurring in the distribution chill chain. The results showed that the end point of TTI, after storage at those fluctuating temperature conditions, was noted very

  15. Saccharomyces cerevisiae variety diastaticus friend or foe? Spoilage potential and brewing ability of different Saccharomyces cerevisiae variety diastaticus yeast isolates by genetic, phenotypic and physiological characterization.

    Science.gov (United States)

    Meier-Dörnberg, Tim; Kory, Oliver Ingo; Jacob, Fritz; Michel, Maximilian; Hutzler, Mathias

    2018-03-06

    Saccharomyces cerevisiae variety diastaticus is generally considered to be an obligatory spoilage microorganism and spoilage yeast in beer and beer-mixed beverages (Folz, Hofmann and Stahl 2011; Hutzler et al. 2012). Their super-attenuating ability causes increased carbon dioxide concentrations, beer gushing and potential bottle explosion along with changes in flavor, sedimentation and increased turbidity. This research shows clear differences in the super-attenuating properties of S. cerevisiae var. diastaticus yeast strains and their potential for industrial brewing applications. Nineteen unknown spoilage yeast cultures were obtained as isolates and characterized using a broad spectrum of genetic and phenotypic methods. Results indicated that all isolates represent genetically different S. cerevisiae var. diastaticus strains except for strain TUM PI BA 124. Yeast strains were screened for their super-attenuating ability and sporulation. Even if the STA1 gene responsible for super-attenuation by encoding for the enzyme glucoamylase, could be verified by RT-PCR, no correlation to the spoilage potential could be demonstrated. Seven strains were further characterized focusing on brewing and sensory properties according to the yeast characterization platform developed by Meier-Dörnberg (Meier-Dörnberg and Michel et al. 2017; Meier-Dörnberg and Hutzler et al. 2017). Yeast strain TUM 3-H-2 cannot metabolize dextrin and soluble starch and showed no spoilage potential or super-attenuating ability even when the strain belongs to the species S. cerevisiae var. diastaticus. Overall the beer produced with S. cerevisiae var. diastaticus has a dry and winey body with noticeable phenolic off-flavors desirable in German wheat beers.

  16. Effect of packaging material on the spoilage and shelf life of cooked ...

    African Journals Online (AJOL)

    Nigerian Food Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 27, No 2 (2009) >. Log in or Register to get access to full text downloads.

  17. Food packaging materials and radiation processing of food: a brief review

    International Nuclear Information System (INIS)

    Chuaqui-Offermanns, N.

    1989-01-01

    Food is usually packaged to prevent microbial contamination and spoilage. Ionizing radiation can be applied to food-packaging materials in two ways: (i) sterilization of packaging materials for aseptic packaging, and (ii) radiation processing of prepackaged food. In aseptic packaging, a sterile package is filled with a sterile product in a microbiologically controlled environment. In irradiation of prepackaged food, the food and the packaging material are irradiated simultaneously. For both applications, the radiation stability of the packaging material is a key consideration if the technology is to be used successfully. To demonstrate the radiation stability of the packaging material, it must be shown that irradiation does not significantly alter the physical and chemical properties of the material. The irradiated material must protect the food from environmental contamination while maintaining its organoleptic and toxicological properties. Single-layer plastics cannot meet the requirements of either application. Multilayered structures produced by coextrusion would likely satisfy the demands of radiation processing prepackaged food. In aseptic packaging, the package is irradiated prior to filling, making demands on toxicological safety less stringent. Therefore, multilayered structures produced by coextrusion, lamination or co-injection moulding could satisfy the requirements. (author)

  18. Antimicrobial effect of essential oils on the seafood spoilage micro-organism Photobacterium phosphoreum in liquid media and fish products

    DEFF Research Database (Denmark)

    Mejlholm, Ole; Dalgaard, Paw

    2002-01-01

    Aims: To evaluate the antimicrobial effect of nine essential oils (EO) on P. phosphoreum and determine the effect of oregano oil on the shelf-life of modified atmosphere-packed (MAP) cod fillets. Methods and Results: The antimicrobial effect of EO was studied in a liquid medium and in product...... storage trials. Oils of oregano and cinnamon had strongest antimicrobial activity, followed by lemongrass, thyme, clove, bay, marjoram, sage and basil oils. Oregano oil (0.05%, v/w) reduced growth of P. phosphoreum in naturally contaminated MAP cod fillets and extended shelf-life from 11-12 d to 21-26 d...... at 2degreesC. Conclusions: Oregano oil reduced the growth of P. phosphoreum and extended the shelf-life of MAP cod fillets. Significance and Impact of the Study: Mild and natural preservation using EO can extend the shelf-life of MAP seafood through inhibiting the specific spoilage organism P...

  19. A CTAB based method for the preparation of total protein extract of wine spoilage microrganisms for proteomic analysis.

    Science.gov (United States)

    Polati, Rita; Zapparoli, Giacomo; Giudici, Paolo; Bossi, Alessandra

    2009-04-01

    Mapping the proteome of microrganisms by 2D-electrophoresis is often a hard task, because many contaminants, e.g. polysaccharides of the cell wall and nucleic acid, can obstruct the pores of the IEF gel resulting in streaks and smears. A protocol based on the use of the cationic detergent cetyl-trimethylammonium bromide (CTAB) and its salt-dependent solubility was developed. The cellulose-producing strain Gluconoacetobacter hansenii AAB0248 was resolved on 7cm Minigels in over 500 protein spots (a hundred more than with protocols reported in literature). The method was further employed for mapping the proteome of some acid adapted, wine spoilage microrganisms e.g. acetic acid bacteria and a yeast.

  20. Salt-inducible promoter derivable from a lactic acid bacterium, and its use in a lactic acid bacterium for production of a desired protein

    NARCIS (Netherlands)

    Sanders, Jan Willem; Kok, Jan; Venema, Gerard; Ledeboer, Adrianus Marinus

    1998-01-01

    The invention provides a salt-inducible promoter present in SEQ ID NO: 10 and derivable from a lactic acid bacterium in isolation from the coding sequence normally controlled by said promoter in a wild-type lactic acid bacterium, with modifications and important parts thereof. Also provided are a

  1. Effect of Ethanol, Sulfur Dioxide and Glucose on the Growth of Wine Spoilage Yeasts Using Response Surface Methodology.

    Directory of Open Access Journals (Sweden)

    Mahesh Chandra

    Full Text Available Response surface methodology (RSM was used to study the effect of three factors, sulfur dioxide, ethanol and glucose, on the growth of wine spoilage yeast species, Zygosaccharomyces bailii, Schizosaccharomyces pombe, Saccharomycodes ludwigii and Saccharomyces cerevisiae. Seventeen central composite rotatable design (CCRD trials were designed for each test yeast using realistic concentrations of the factors (variables in premium red wine. Polynomial regression equations were fitted to experimental data points, and the growth inhibitory conditions of these three variables were determined. The overall results showed Sa. ludwigii as the most resistant species growing under high ethanol/free sulfur dioxide concentrations, i.e., 15% (v/v/20 mg L-1, 14% (v/v/32 mg L-1 and 12.5% (v/v/40 mg L-1, whereas other yeasts did not survive under the same levels of ethanol/free sulfur dioxide concentrations. The inhibitory effect of ethanol was primarily observed during longer incubation periods, compared with sulfur dioxide, which showed an immediate effect. In some CCRD trials, Sa. ludwigii and S. cerevisiae showed growth recovery after a short death period under the exposure of 20-32 mg L-1 sulfur dioxide in the presence of 11% (v/v or more ethanol. However, Sc. pombe and Z. bailii did not show such growth recovery under similar conditions. Up to 10 g L-1 of glucose did not prevent cell death under the sulfur dioxide or ethanol stress. This observation demonstrates that the sugar levels commonly used in wine to sweeten the mouthfeel do not increase wine susceptibility to spoilage yeasts, contrary to the anecdotal evidence.

  2. Effect of Ethanol, Sulfur Dioxide and Glucose on the Growth of Wine Spoilage Yeasts Using Response Surface Methodology.

    Science.gov (United States)

    Chandra, Mahesh; Oro, Inês; Ferreira-Dias, Suzana; Malfeito-Ferreira, Manuel

    2015-01-01

    Response surface methodology (RSM) was used to study the effect of three factors, sulfur dioxide, ethanol and glucose, on the growth of wine spoilage yeast species, Zygosaccharomyces bailii, Schizosaccharomyces pombe, Saccharomycodes ludwigii and Saccharomyces cerevisiae. Seventeen central composite rotatable design (CCRD) trials were designed for each test yeast using realistic concentrations of the factors (variables) in premium red wine. Polynomial regression equations were fitted to experimental data points, and the growth inhibitory conditions of these three variables were determined. The overall results showed Sa. ludwigii as the most resistant species growing under high ethanol/free sulfur dioxide concentrations, i.e., 15% (v/v)/20 mg L-1, 14% (v/v)/32 mg L-1 and 12.5% (v/v)/40 mg L-1, whereas other yeasts did not survive under the same levels of ethanol/free sulfur dioxide concentrations. The inhibitory effect of ethanol was primarily observed during longer incubation periods, compared with sulfur dioxide, which showed an immediate effect. In some CCRD trials, Sa. ludwigii and S. cerevisiae showed growth recovery after a short death period under the exposure of 20-32 mg L-1 sulfur dioxide in the presence of 11% (v/v) or more ethanol. However, Sc. pombe and Z. bailii did not show such growth recovery under similar conditions. Up to 10 g L-1 of glucose did not prevent cell death under the sulfur dioxide or ethanol stress. This observation demonstrates that the sugar levels commonly used in wine to sweeten the mouthfeel do not increase wine susceptibility to spoilage yeasts, contrary to the anecdotal evidence.

  3. Spoilage-related activity of Carnobacterium maltaromaticum strains in air-stored and vacuum-packed meat.

    Science.gov (United States)

    Casaburi, Annalisa; Nasi, Antonella; Ferrocino, Ilario; Di Monaco, Rossella; Mauriello, Gianluigi; Villani, Francesco; Ercolini, Danilo

    2011-10-01

    One hundred three isolates of Carnobacterium spp. from raw meat were analyzed by random amplification of polymorphic DNA (RAPD) and PCR and were identified by 16S rRNA gene sequencing. Forty-five strains of Carnobacterium maltaromaticum were characterized for their growth capabilities at different temperatures, NaCl concentrations, and pH values and for in vitro lipolytic and proteolytic activities. Moreover, their spoilage potential in meat was investigated by analyzing the release of volatile organic compounds (VOCs) in meat stored in air or vacuum packs. Almost all the strains were able to grow at 4, 10, and 20°C, at pH values of 6 to 9, and in the presence of 2.5% NaCl. The release of VOCs by each strain in beef stored at 4°C in air and vacuum packs was evaluated by headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS) analysis. All the meat samples inoculated and stored in air showed higher numbers of VOCs than the vacuum-packed meat samples. Acetoin, 1-octen-3-ol, and butanoic acid were the compounds most frequently found under both storage conditions. The contaminated meat samples were evaluated by a sensory panel; the results indicated that for all sensory odors, no effect of strain was significant (P > 0.05). The storage conditions significantly affected (P meat, and mozzarella cheese odors, which were more intense in meat stored in air than in vacuum packs but were never very intense. In conclusion, different strains of C. maltaromaticum can grow efficiently in meat stored at low temperatures both in air and in vacuum packs, producing volatile molecules with low sensory impacts, with a negligible contribution to meat spoilage overall.

  4. Spoilage-Related Activity of Carnobacterium maltaromaticum Strains in Air-Stored and Vacuum-Packed Meat ▿ †

    Science.gov (United States)

    Casaburi, Annalisa; Nasi, Antonella; Ferrocino, Ilario; Di Monaco, Rossella; Mauriello, Gianluigi; Villani, Francesco; Ercolini, Danilo

    2011-01-01

    One hundred three isolates of Carnobacterium spp. from raw meat were analyzed by random amplification of polymorphic DNA (RAPD) and PCR and were identified by 16S rRNA gene sequencing. Forty-five strains of Carnobacterium maltaromaticum were characterized for their growth capabilities at different temperatures, NaCl concentrations, and pH values and for in vitro lipolytic and proteolytic activities. Moreover, their spoilage potential in meat was investigated by analyzing the release of volatile organic compounds (VOCs) in meat stored in air or vacuum packs. Almost all the strains were able to grow at 4, 10, and 20°C, at pH values of 6 to 9, and in the presence of 2.5% NaCl. The release of VOCs by each strain in beef stored at 4°C in air and vacuum packs was evaluated by headspace solid-phase microextraction (HS-SPME)-gas chromatography-mass spectrometry (GC-MS) analysis. All the meat samples inoculated and stored in air showed higher numbers of VOCs than the vacuum-packed meat samples. Acetoin, 1-octen-3-ol, and butanoic acid were the compounds most frequently found under both storage conditions. The contaminated meat samples were evaluated by a sensory panel; the results indicated that for all sensory odors, no effect of strain was significant (P > 0.05). The storage conditions significantly affected (P meat, and mozzarella cheese odors, which were more intense in meat stored in air than in vacuum packs but were never very intense. In conclusion, different strains of C. maltaromaticum can grow efficiently in meat stored at low temperatures both in air and in vacuum packs, producing volatile molecules with low sensory impacts, with a negligible contribution to meat spoilage overall. PMID:21784913

  5. Potential of medicinal plants as antimicrobial and antioxidant agents in food industry: a hypothesis.

    Science.gov (United States)

    Ortega-Ramirez, Luis Alberto; Rodriguez-Garcia, Isela; Leyva, Juan Manuel; Cruz-Valenzuela, Manuel Reynaldo; Silva-Espinoza, Brenda Adriana; Gonzalez-Aguilar, Gustavo A; Siddiqui, Wasim; Ayala-Zavala, Jesus Fernando

    2014-02-01

    Many food preservation strategies can be used for the control of microbial spoilage and oxidation; however, these quality problems are not yet controlled adequately. Although synthetic antimicrobial and antioxidant agents are approved in many countries, the use of natural safe and effective preservatives is a demand of food consumers and producers. This paper proposes medicinal plants, traditionally used to treat health disorders and prevent diseases, as a source of bioactive compounds having food additive properties. Medicinal plants are rich in terpenes and phenolic compounds that present antimicrobial and antioxidant properties; in addition, the literature revealed that these bioactive compounds extracted from other plants have been effective in food systems. In this context, the present hypothesis paper states that bioactive molecules extracted from medicinal plants can be used as antimicrobial and antioxidant additives in the food industry. © 2014 Institute of Food Technologists®

  6. Irradiation pilot plants and experimental facilities available for food preservation

    International Nuclear Information System (INIS)

    1975-01-01

    With the ever-increasing world food crisis mankind has to face today, the prevention of spoilage of perishable food is gaining in momentum. The World Food Conference (Rome, November 1974) of the United Nations clearly recognized the importance of food preservation and urged action in this field. Irradiation is one of the recently discovered methods to preserve food. Its practical introduction largely depends on three main factors: (a) proof of the safety for human consumption of the irradiated product, (b) technological feasibility and (c) economic competitiveness of the process. As data on safety for consumption ('wholesomeness') continue to become available, the number of countries authorizing the irradiation of certain food items is growing (present total: 17 countries), and the same is true for the number of licensed irradiated commodities (total: 23). Under these conditions, testing of the technological and economic feasibility of food irradiation is a matter of increasing importance. Economic feasibility of any industrial operation can only be studied in larger-scale experiments. Thus, they can only be performed with radiation sources larger than those found in laboratories, i.e. in pilot irradiators, capable of handling from a few hundred to a few thousand kilograms of material within a short period of time. The Food Preservation Section of the Joint FAO/IAEA Division of Atomic Energy in Food and Agriculture has attempted to collect data on the availability, for food preservation, of suitable irradiators in Member States

  7. Nuclear techniques for food and agricultural development: 1964-94

    International Nuclear Information System (INIS)

    Sigurbjoernsson, B.; Vose, P.

    1994-01-01

    Over the past 30 years, programmes of the Joint FAO/IAEA Division have helped countries solve practical, and costly, problems in areas of soil fertility, irrigation, and crop production; plant breeding and genetics; animal production and health; insect and pest control; agrochemicals and residues; and food preservation. The Division's overall objectives are to exploit the potential for application of isotopes and radiation techniques in agricultural research and development; to increase and stabilize agricultural production; to reduce production costs; to improve the quality of food; to protect agricultural products from spoilage and losses; and to minimize pollution of food and the agricultural environment. On the occasion of the Joint Division's 30th anniversary year, this article highlights selected achievements over the past three decades

  8. Food production - Present and future development

    International Nuclear Information System (INIS)

    Lamm, C.G.

    1974-01-01

    This year the joint FAO/IAEA Division of Atomic Energy in Food and Agriculture celebrates its 10th anniversary. The aim of these two United Nations organizations is to ensure that the technical services of both FAO and IAEA are fully co-ordinated and their programmes are designed to assist developing Member States to apply isotopes and radiation techniques to the solution of food and agricultural problems. More precisely, the medium-term objectives of the Joint Division are to exploit the potential of nuclear techniques in research and development for increasing and stabilizing agricultural production, improving food quality, protecting agricultural products from spoilage and losses and minimizing pollution of food and the agricultural environment. This account of what radioisotopes can do for man in the agricultural field is therefore to a great extent a review of the activities of the Joint Division and a prediction of its future fields of emphasis, especially in the light of the present long-range and world-wide food crisis. (author)

  9. Probiotics: a comprehensive approach toward health foods.

    Science.gov (United States)

    Sharma, Monika; Devi, Mridula

    2014-01-01

    Food products containing probiotics and prebiotics are an important development in Health foods, which enhance health promoting microbial flora in the intestine. Probiotic refers to viable microorganism that promotes or support a beneficial balance of the autochthonous microbial population of the gastrointestinal tract. A number of genera of bacteria (and yeast) are used as probiotics, including Lactobacillus, Leuconostoc, Pediococcus, Bifidobacterium, Saccharomyces, and Enterococcus, but the main species believed to have probiotic characteristics are Lactobacillus acidophilus, Bifidobacterium spp., and L. casei. Probiotics can reduce diarrheal incidence, lactose intolerance, lower serum cholesterol, stimulate the immune system, control infections, act as antibiotics, suppress tumors, and protect against colon or bladder cancer by maintaining a healthy intestinal microflora balance. Lactic acid bacteria produce biopreservatives such as lactic acid, hydrogen peroxide, and bacteriocins that are used to retard both spoilage and the growth of pathogenic bacteria. Food, particularly dairy products are considered as an ideal vehicle for delivering probiotic bacteria to the human gastrointestinal tract. Cereals being rich source of prebiotics such as β-glucan and arabinoxylan, galacto-, and fructooligosaccharides are considered for development of probiotic foods. Good manufacturing practices must be applied in the manufacture of probiotic foods with quality assurance, and shelf-life conditions established.

  10. Psychological aspects of food safety risk perception

    DEFF Research Database (Denmark)

    Scholderer, Joachim

    Most consumers are not microbiologists and spend little time worrying about food safety. Evolution and civilisation have provided us with abilities to avoid the more serious risks, and in practice we tend to use these abilities quite well. However, there are certain conditions under which...... signals, motivating approach. Novelty, and the detection of certain olfactory and visual cues associated with spoilage or contamination, act as orientation or threat signals and motivate closer inspection or avoidance. Anticipatory affects are an inherent part of these behaviour regulation systems...... that would make avoidance behaviour socially inappropriate. The four conditions are illustrated with examples from past and ongoing research. Since many of the involved mechanisms operate almost automatically, interventions that are based on occasional risk communication alone are unlikely to have lasting...

  11. Clostridium difficile in Food and Animals: A Comprehensive Review.

    Science.gov (United States)

    Rodriguez, C; Taminiau, B; Van Broeck, J; Delmée, M; Daube, G

    2016-01-01

    Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment, and the bacterium is able to colonise the intestinal tract of both animals and humans. Since domestic and food animals frequently test positive for toxigenic C. difficile, even without showing any signs of disease, it seems plausible that C. difficile could be zoonotic. Therefore, animals could play an essential role as carriers of the bacterium. In addition, the presence of the spores in different meats, fish, fruits and vegetables suggests a risk of foodborne transmission. This review summarises the current available data on C. difficile in animals and foods, from when the bacterium was first described up to the present.

  12. Chitin utilization by the insect-transmitted bacterium Xylella fastidiosa.

    Science.gov (United States)

    Killiny, Nabil; Prado, Simone S; Almeida, Rodrigo P P

    2010-09-01

    Xylella fastidiosa is an insect-borne bacterium that colonizes xylem vessels of a large number of host plants, including several crops of economic importance. Chitin is a polysaccharide present in the cuticle of leafhopper vectors of X. fastidiosa and may serve as a carbon source for this bacterium. Biological assays showed that X. fastidiosa reached larger populations in the presence of chitin. Additionally, chitin induced phenotypic changes in this bacterium, notably increasing adhesiveness. Quantitative PCR assays indicated transcriptional changes in the presence of chitin, and an enzymatic assay demonstrated chitinolytic activity by X. fastidiosa. An ortholog of the chitinase A gene (chiA) was identified in the X. fastidiosa genome. The in silico analysis revealed that the open reading frame of chiA encodes a protein of 351 amino acids with an estimated molecular mass of 40 kDa. chiA is in a locus that consists of genes implicated in polysaccharide degradation. Moreover, this locus was also found in the genomes of closely related bacteria in the genus Xanthomonas, which are plant but not insect associated. X. fastidiosa degraded chitin when grown on a solid chitin-yeast extract-agar medium and grew in liquid medium with chitin as the sole carbon source; ChiA was also determined to be secreted. The gene encoding ChiA was cloned into Escherichia coli, and endochitinase activity was detected in the transformant, showing that the gene is functional and involved in chitin degradation. The results suggest that X. fastidiosa may use its vectors' foregut surface as a carbon source. In addition, chitin may trigger X. fastidiosa's gene regulation and biofilm formation within vectors. Further work is necessary to characterize the role of chitin and its utilization in X. fastidiosa.

  13. Liver abscess associated with an oral flora bacterium Streptococcus anginosus

    Directory of Open Access Journals (Sweden)

    Hava Yılmaz

    2012-03-01

    Full Text Available Viridans group Streptococcus, a bacterium of the oral flora has a low-virulence and rarely causes liver abscess. A 40-yearoldmale patient was admitted to the hospital complaining of high fever and malaise. A physical examination revealedpoor oral hygiene; there were caries on many teeth, and he had hepatomegaly. A hepatic abscess was identified inhis abdominal tomography. Streptococcus anginosus was isolated from the drainage material, and the bile ducts werenormal in his MRI cholangiography. An immunocompetent case of liver abscess caused by Streptococcus anginosusoriginated most probably from oral flora is presented here. J Microbiol Infect Dis 2012; 2(1:33-35

  14. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    Energy Technology Data Exchange (ETDEWEB)

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  15. Research Progress and Perspectives of Nitrogen Fixing Bacterium, Gluconacetobacter diazotrophicus, in Monocot Plants

    Directory of Open Access Journals (Sweden)

    N. Eskin

    2014-01-01

    Full Text Available Gluconacetobacter diazotrophicus is a nitrogen fixing bacterium originally found in monocotyledon sugarcane plants in which the bacterium actively fixes atmosphere nitrogen and provides significant amounts of nitrogen to plants. This bacterium mainly colonizes intercellular spaces within the roots and stems of plants and does not require the formation of the complex root organ like nodule. The bacterium is less plant/crop specific and indeed G. diazotrophicus has been found in a number of unrelated plant species. Importantly, as the bacterium was of monocot plant origin, there exists a possibility that the nitrogen fixation feature of the bacterium may be used in many other monocot crops. This paper reviews and updates the research progress of G. diazotrophicus for the past 25 years but focuses on the recent research development.

  16. The Importance of Endospore-Forming Bacteria Originating from Soil for Contamination of Industrial Food Processing

    Directory of Open Access Journals (Sweden)

    Marc Heyndrickx

    2011-01-01

    Full Text Available Specific endospore formers have become important contaminants in industrial food processing. The direct or indirect soil route of contamination or dispersal is the start of events or processes in the agrofood chain that eventually leads to important problems or concerns for food safety and/or quality. Three important food sectors are discussed in this paper. In the dairy sector, Bacillus cereus, the most important pathogen or spoilage organism in this sector, and Clostridium tyrobutyricum, the most important spoiler in certain cheeses, both contaminate pasteurized milk through the faecal and/or (at least for B. cereus the direct soil route. In the fruit juice industry, Alicyclobacillus acidoterrestris, present on raw fruits, has become a major quality-target organism. In the ready-to-eat food sector, B. cereus and other aerobic endospore formers are introduced via vegetables, fruits, or herbs and spices, while anaerobic spore formers like nonproteolytic Clostridium botulinum and Clostridium estertheticum pose safety and spoilage risks in chilled packaged foods, respectively.

  17. The Importance of Endospore-Forming Bacteria Originating from Soil for Contamination of Industrial Food Processing

    International Nuclear Information System (INIS)

    Heyndrickx, M

    2011-01-01

    Specific endo spore formers have become important contaminants in industrial food processing. The direct or indirect soil route of contamination or dispersal is the start of events or processes in the agrofood chain that eventually leads to important problems or concerns for food safety and/or quality. Three important food sectors are discussed in this paper. In the dairy sector, Bacillus cereus, the most important pathogen or spoilage organism in this sector, and Clostridium tyrobutyricum, the most important spoiler in certain cheeses, both contaminate pasteurized milk through the faecal and/or (at least for B. cereus) the direct soil route. In the fruit juice industry, Alicyclobacillus acidoterrestris, present on raw fruits, has become a major quality-target organism. In the ready-to-eat food sector, B. cereus and other aerobic endo spore formers are introduced via vegetables, fruits, or herbs and spices, while anaerobic spore formers like non proteolytic Clostridium botulinum and Clostridium estertheticum pose safety and spoilage risks in chilled packaged foods, respectively

  18. Influence of some physical treatments and natural food preservatives on the diversity of microorganisms in certain Egyptian juices

    International Nuclear Information System (INIS)

    Abu El-Naga, M.N.Z.I.

    2009-01-01

    Foods begin to lose their quality from the moment they are harvested through changes resulting from physical, chemical, enzymatic, or microbiological reactions. Food preservation prevents deteriorative reaction, extending the shelf life and assuring its safety. Microorganisms and enzymes are the main agents responsible for food spoilages and therefore the targets of preservation techniques. The i deal m ethod of food preservation has the following characteristics: It improves shelf life and safety by inactivating spoilage and pathogenic microorganisms. It dose not leave residues. It is cheap and convenient to apply. It encounters no objection from consumers and legislators. One of the major advances in human history was the ability to preserve food. It was the perquisite to man setting down in one place instead of moving from place to place in the never ending hunt for fresh food. The earliest preservation technologies developed were drying, smoking, chilling and heating. The use of various compounds such as salts and spices to preserve food was also used in ancient times

  19. Novel Biocontrol Methods for Listeria monocytogenes Biofilms in Food Production Facilities

    Directory of Open Access Journals (Sweden)

    Jessica A. Gray

    2018-04-01

    Full Text Available High mortality and hospitalization rates have seen Listeria monocytogenes as a foodborne pathogen of public health importance for many years and of particular concern for high-risk population groups. Food manufactures face an ongoing challenge in preventing the entry of L. monocytogenes into food production environments (FPEs due to its ubiquitous nature. In addition to this, the capacity of L. monocytogenes strains to colonize FPEs can lead to repeated identification of L. monocytogenes in FPE surveillance. The contamination of food products requiring product recall presents large economic burden to industry and is further exacerbated by damage to the brand. Poor equipment design, facility layout, and worn or damaged equipment can result in Listeria hotspots and biofilms where traditional cleaning and disinfecting procedures may be inadequate. Novel biocontrol methods may offer FPEs effective means to help improve control of L. monocytogenes and decrease cross contamination of food. Bacteriophages have been used as a medical treatment for many years for their ability to infect and lyse specific bacteria. Endolysins, the hydrolytic enzymes of bacteriophages responsible for breaking the cell wall of Gram-positive bacteria, are being explored as a biocontrol method for food preservation and in nanotechnology and medical applications. Antibacterial proteins known as bacteriocins have been used as alternatives to antibiotics for biopreservation and food product shelf life extension. Essential oils are natural antimicrobials formed by plants and have been used as food additives and preservatives for many years and more recently as a method to prevent food spoilage by microorganisms. Competitive exclusion occurs naturally among bacteria in the environment. However, intentionally selecting and applying bacteria to effect competitive exclusion of food borne pathogens has potential as a biocontrol application. This review discusses these novel biocontrol

  20. Food Allergy

    Science.gov (United States)

    Food allergy is an abnormal response to a food triggered by your body's immune system. In adults, the foods ... a severe reaction called anaphylaxis. Symptoms of food allergy include Itching or swelling in your mouth Vomiting, ...

  1. Biodegradation of polyethylene by the thermophilic bacterium Brevibacillus borstelensis.

    Science.gov (United States)

    Hadad, D; Geresh, S; Sivan, A

    2005-01-01

    To select a polyethylene-degrading micro-organism and to study the factors affecting its biodegrading activity. A thermophilic bacterium Brevibaccillus borstelensis strain 707 (isolated from soil) utilized branched low-density polyethylene as the sole carbon source and degraded it. Incubation of polyethylene with B. borstelensis (30 days, 50 degrees C) reduced its gravimetric and molecular weights by 11 and 30% respectively. Brevibaccillus borstelensis also degraded polyethylene in the presence of mannitol. Biodegradation of u.v. photo-oxidized polyethylene increased with increasing irradiation time. Fourier Transform Infra-Red (FTIR) analysis of photo-oxidized polyethylene revealed a reduction in carbonyl groups after incubation with the bacteria. This study demonstrates that polyethylene--considered to be inert--can be biodegraded if the right microbial strain is isolated. Enrichment culture methods were effective for isolating a thermophilic bacterium capable of utilizing polyethylene as the sole carbon and energy source. Maximal biodegradation was obtained in combination with photo-oxidation, which showed that carbonyl residues formed by photo-oxidation play a role in biodegradation. Brevibaccillus borstelensis also degraded the CH2 backbone of nonirradiated polyethylene. Biodegradation of polyethylene by a single bacterial strain contributes to our understanding of the process and the factors affecting polyethylene biodegradation.

  2. Biological Control of Meloidogyne hapla Using an Antagonistic Bacterium

    Directory of Open Access Journals (Sweden)

    Jiyeong Park

    2014-09-01

    Full Text Available We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN Meloidogyne hapla in carrot (Daucus carota subsp. sativus and tomato (Solanum lycopersicum. Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.

  3. Significance of volatile compounds produced by spoilage bacteria in vacuum-packed cold-smoked salmon ( Salmo salar ) analyzed by GC-MS and multivariate regression

    DEFF Research Database (Denmark)

    Jørgensen, Lasse Vigel; Huss, Hans Henrik; Dalgaard, Paw

    2001-01-01

    , 1- penten-3-ol, and 1-propanol. The potency and importance of these compounds was confirmed by gas chromatography- olfactometry. The present study provides valuable information on the bacterial reactions responsible for spoilage off-flavors of cold-smoked salmon, which can be used to develop......Changes were studied in the concentration of 38 volatile compounds during chilled storage at 5 degreesC of six lots of commercially produced vacuum-packed cold-smoked salmon and sterile cold-smoked salmon. The majority of volatile compounds produced during spoilage of cold-smoked salmon were...... alcohols, which were produced by microbial activity. Partial least- squares regression of volatile compounds and sensory results allowed for a multiple compound quality index to be developed. This index was based on volatile bacterial metabolites, 1- propanol and 2-butanone, and 2-furan...

  4. Evaluation of the role of Carnobacterium piscicola in spoilage of vacuum- and modified-atmosphere-packed cold-smoked salmon stored at 5 degrees C

    DEFF Research Database (Denmark)

    Paludan-Müller, Christine; Dalgaard, Paw; Huss, Hans Henrik

    1998-01-01

    The microflora on spoiled cold-smoked salmon often consists of a mixture of lactic acid bacteria (LAB) and Gram-negative bacteria. To elucidate the role of the different groups, a storage trial was carried out in which nisin and CO2 were used for the selective inhibition of the two bacterial groups...... piscicola, which was found to account for 87% of the 255 LAB isolates characterized. Whole-cell-protein patterns analysed by SDS-PAGE confirmed the Carnobacterium species identification. The spoilage potential of C. piscicola isolates was further studied by inoculation of approx. 10(6) cfu/g in cold......, rancid and bitter off-flavours at the point of spoilage, irrespective of the length of shelf-life and low or high total counts of LAB and Gram-negative bacteria. (C) 1998 Elsevier Science B.V...

  5. Sensory characteristics of spoilage and volatile compounds associated with bacteria isolated from cooked and peeled tropical shrimps using SPME-GC-MS analysis

    OpenAIRE

    Jaffres, Emmanuel; Lalanne, Valerie; Mace, Sabrina; Cornet, Josiane; Cardinal, Mireille; Serot, Thierry; Dousset, Xavier; Joffraud, Jean-jacques

    2011-01-01

    The spoilage potential of six bacterial species isolated from cooked and peeled tropical shrimps (Brochothrix thermosphacta, Serratia liquefaciens-like, Carnobacterium maltaromaticum, Carnobacterium divergens, Carnobacterium alterfunditum-like and Vagococcus penaei sp. nov.) was evaluated. The bacteria were inoculated into shrimps, packaged in a modified atmosphere and stored for 27 days at 8 °C. Twice a week, microbial growth, as well as chemical and sensory changes, were monitored during th...

  6. Evaluation of the spoilage potential of bacteria isolated from spoiled cooked whole tropical shrimp (Penaeus vannamei) stored under modified atmosphere packaging

    OpenAIRE

    Mace, Sabrina; Cardinal, Mireille; Jaffres, Emmanuel; Cornet, Josiane; Lalanne, Valerie; Chevalier, Frederique; Serot, Thierry; Pilet, Marie-france; Dousset, Xavier; Joffraud, Jean-jacques

    2014-01-01

    The spoilage potential of isolates belonging to five bacterial groups/species (Shewanella baltica, Carnobacterium maltaromaticum, Aeromonas salmonicida, Vibrio sp., “other Gamma-Proteobacteria” [containing one strain of Pseudoalteromonas sp. and one strain of Psychrobacter sp.]) isolated from spoiled cooked and whole tropical shrimp stored under modified atmosphere packaging (MAP) was evaluated by inoculation into ionized cooked and peeled tropical shrimp followed by storage for 32 days at 8°...

  7. Sensors for Food Safety and Security

    Science.gov (United States)

    Papkovsky, Dmitri B.

    Active packaging of food products is aimed at extending shelf life, preserving and improving quality, taste characteristics and appearance of a product. Modified atmosphere packaging (MAP) have become widely used with oxygen sensitive foods, as it enables to inhibit or delay undesirable processes inside packs such as oxidation of lipids and hemecontaining pigments, enzymatic degradation, microbial spoilage, etc. In MAP process, the package container with food is flushed with a mixture of CO2, N2, and O2 gases to replace air, and then sealed. The function of CO2 is to decrease the growth rate of micro-organisms, N2 displaces O2 and also prevents the packaging from collapsing when some of the CO2 is absorbed by moisture in the product1. The majority of MAP foods are packed under the atmosphere with considerably reduced oxygen levels, while products such as raw meat, fruit and vegetables require high concentration of oxygen to keep their appearance and/or shelf life.

  8. Characterisation of the spoilage microbiota in raw salmon (Salmo salar) steaks stored under vacuum or modified atmosphere packaging combining conventional methods and PCR-TTGE.

    Science.gov (United States)

    Macé, Sabrina; Cornet, Josiane; Chevalier, Frédérique; Cardinal, Mireille; Pilet, Marie-France; Dousset, Xavier; Joffraud, Jean-Jacques

    2012-05-01

    In order to characterise the spoilage related to microbiota of raw salmon, a combination of culture-dependent and -independent methods, including PCR-TTGE, was used to analyse 3 raw salmon batches stored for 3 days at chilled temperature in modified atmosphere packaging (MAP) (50% CO₂/50% N₂) or under vacuum. Sensory evaluation, microbiological enumeration and chemical analysis were performed after 3, 7 and 10 days of storage. At the onset of spoilage, 65 bacterial isolates were picked from the plates. Thus, 13 different genera or species were identified by phenotypic and molecular tests: Serratia spp., Photobacterium phosphoreum, Yersinia intermedia, Hafnia alvei, Buttiauxella gaviniae, Pseudomonas sp., Carnobacterium maltaromaticum, Carnobacterium divergens, Lactococcus piscium, Lactobacillus fuchuensis, Vagococcus carniphilus, Leuconostoc gasicomitatum and Brochothrix thermosphacta. The PCR-TTGE profiles and band identification enabled a shift of the dominant populations during the storage to be visualised for all the batches, probably due to the temperature change and the packaging. At the beginning of storage, Pseudomonas sp. dominated the raw salmon microbiota while in the following days (7 and 10), P. phosphoreum and L. piscium were identified as the main bacterial groups. This study enhances the knowledge of MAP and vacuum-packed raw salmon spoilage microbiota. Copyright © 2011 Elsevier Ltd. All rights reserved.

  9. Rapid monitoring of the spoilage of minced beef stored under conventionally and active packaging conditions using Fourier transform infrared spectroscopy in tandem with chemometrics.

    Science.gov (United States)

    Ammor, Mohammed Salim; Argyri, Anthoula; Nychas, George-John E

    2009-03-01

    Fourier transform infrared (FTIR) spectroscopy was exploited to measure biochemical changes within fresh minced beef in an attempt to rapidly monitor beef spoilage. Minced beef packaged either aerobically, under modified atmosphere and using an active packaging were held from freshness to spoilage at 0, 5, 10, and 15°C. Frequent FTIR measurements were collected directly from the sample surface using attenuated total reflectance, in parallel the total viable counts of bacteria, the sensory quality and the pH were also determined. Principal components analysis allowed illuminating the wavenumbers potentially correlated with the spoilage process. Qualitative interpretation of spectral data was carried out using discriminant factorial analysis and used to corroborate sensory data and to accurately determine samples freshness and packaging. Partial least-squares regressions permitted estimates of bacterial loads and pH values from the spectral data with a fit of R(2)=0.80 for total viable counts and fit of R(2)=0.92 for the pH. Obtained results demonstrated that a FTIR spectrum may be considered as a metabolic fingerprint and that the method in tandem with chemometrics represents a powerful, rapid, economical and non-invasive method for monitoring minced beef freshness regardless the storage conditions (e.g. packaging and temperature).

  10. Differentiation of Lactobacillus brevis strains using Matrix-Assisted-Laser-Desorption-Ionization-Time-of-Flight Mass Spectrometry with respect to their beer spoilage potential.

    Science.gov (United States)

    Kern, Carola C; Vogel, Rudi F; Behr, Jürgen

    2014-06-01

    Lactobacillus (L.) brevis is one of the most frequently encountered bacteria in beer-spoilage incidents. As the species Lactobacillus brevis comprises strains showing varying ability to grow in beer, ranging from growth in low hopped wheat to highly hopped pilsner beer, differentiation and classification of L. brevis with regard to their beer-spoiling ability is of vital interest for the brewing industry. Matrix-Assisted-Laser-Desorption-Ionization-Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) has been shown as a powerful tool for species and sub-species differentiation of bacterial isolates and is increasingly used for strain-level differentiation. Seventeen L. brevis strains, representative of different spoilage types, were characterized according to their tolerance to iso-alpha-acids and their growth in wheat-, lager- and pilsner beer. MALDI-TOF MS spectra were acquired to perform strain-level identification, cluster analysis and biomarker detection. Strain-level identification was achieved in 90% out of 204 spectra. Misidentification occurred nearly exclusively among strains belonging to the same spoilage type. Though spectra of strongly beer-spoiling strains showed remarkable similarity, no decisive single markers were detected to be present in all strains of one group. However, MALDI-TOF MS spectra can be reliably assigned to the corresponding strain and thus allow to track single strains and connect them to their physiological properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Spoilage of Microfiltered and Pasteurized Extended Shelf Life Milk Is Mainly Induced by Psychrotolerant Spore-Forming Bacteria that often Originate from Recontamination.

    Science.gov (United States)

    Doll, Etienne V; Scherer, Siegfried; Wenning, Mareike

    2017-01-01

    Premature spoilage and varying product quality due to microbial contamination still constitute major problems in the production of microfiltered and pasteurized extended shelf life (ESL) milk. Spoilage-associated bacteria may enter the product either as part of the raw milk microbiota or as recontaminants in the dairy plant. To identify spoilage-inducing bacteria and their routes of entry, we analyzed end products for their predominant microbiota as well as the prevalence and biodiversity of psychrotolerant spores in bulk tank milk. Process analyses were performed to determine the removal of psychrotolerant spores at each production step. To detect transmission and recontamination events, strain typing was conducted with isolates obtained from all process stages. Microbial counts in 287 ESL milk packages at the end of shelf life were highly diverse ranging from shelf life is influenced only to a minor extent by raw-milk-associated factors. In contrast, recontamination with spores, particularly from the B. cereus complex, seems to occur. To enhance milk quality throughout the entire shelf life, improved plant sanitation and disinfection that target the elimination of spores are necessary.

  12. Microbial Profile of Soil-Free versus In-Soil Grown Lettuce and Intervention Methodologies to Combat Pathogen Surrogates and Spoilage Microorganisms on Lettuce.

    Science.gov (United States)

    Sirsat, Sujata A; Neal, Jack A

    2013-11-11

    Aquaponics is an effective method to practice sustainable agriculture and is gaining popularity in the US; however, the microbial safety of aquaponically grown produce needs to be ascertained. Aquaponics is a unique marriage of fish production and soil-free produce (e.g., leafy greens) production. Fish are raised in fresh water tanks that are connected to water filled beds where fruits and vegetables are grown. The fish bi-products create nutrient-rich water that provides the key elements for the growth of plants and vegetables. The objective of this study was to perform a comparative analysis of the microbial safety and quality of aquaponic lettuce and soil grown lettuce (conventional, bagged, certified organic, and field lettuce). Following this, an intervention study was performed to combat foodborne pathogen surrogates ( Salmonella and E. coli ), spoilage, and fecal microorganisms using 2.5% acetic acid. The results of the comparative analysis study showed that aquaponically grown lettuce had significantly lower concentration of spoilage and fecal microorganisms compared to in-soil grown lettuce. The intervention study showed that diluted vinegar (2.5% acetic acid) significantly reduced Salmonella , E. coli , coliforms, and spoilage microorganisms on fresh lettuce by 2 to 3 log CFU/g. Irrespective of growing methods (in-soil or soilless), it is crucial to incorporate good agricultural practices to reduce microbial contamination on fresh produce. The intervention employed in this study can be proposed to small farmers and consumers to improve quality and safety of leafy greens.

  13. Microbial Profile of Soil-Free versus In-Soil Grown Lettuce and Intervention Methodologies to Combat Pathogen Surrogates and Spoilage Microorganisms on Lettuce

    Directory of Open Access Journals (Sweden)

    Sujata A. Sirsat

    2013-11-01

    Full Text Available Aquaponics is an effective method to practice sustainable agriculture and is gaining popularity in the US; however, the microbial safety of aquaponically grown produce needs to be ascertained. Aquaponics is a unique marriage of fish production and soil-free produce (e.g., leafy greens production. Fish are raised in fresh water tanks that are connected to water filled beds where fruits and vegetables are grown. The fish bi-products create nutrient-rich water that provides the key elements for the growth of plants and vegetables. The objective of this study was to perform a comparative analysis of the microbial safety and quality of aquaponic lettuce and soil grown lettuce (conventional, bagged, certified organic, and field lettuce. Following this, an intervention study was performed to combat foodborne pathogen surrogates (Salmonella and E. coli, spoilage, and fecal microorganisms using 2.5% acetic acid. The results of the comparative analysis study showed that aquaponically grown lettuce had significantly lower concentration of spoilage and fecal microorganisms compared to in-soil grown lettuce. The intervention study showed that diluted vinegar (2.5% acetic acid significantly reduced Salmonella, E. coli, coliforms, and spoilage microorganisms on fresh lettuce by 2 to 3 log CFU/g. Irrespective of growing methods (in-soil or soilless, it is crucial to incorporate good agricultural practices to reduce microbial contamination on fresh produce. The intervention employed in this study can be proposed to small farmers and consumers to improve quality and safety of leafy greens.

  14. Microbiological spoilage and volatiles production of gutted European sea bass stored under air and commercial modified atmosphere package at 2 °C.

    Science.gov (United States)

    Parlapani, Foteini F; Haroutounian, Serkos A; Nychas, George-John E; Boziaris, Ioannis S

    2015-09-01

    Microbiological, sensory, TVB-N and TMA-N changes and Volatile Organic Compounds (VOCs) detection using the SPME/GC-MS technique, were performed to evaluate potential chemical spoilage indices (CSI) of gutted sea bass (Dicentrarchus labrax) stored at 2 °C under air and in modified atmosphere packaging (MAP CO2: 60%, O2: 10%, N2: 30%). Shelf-life, determined by sensory evaluation, of gutted sea bass stored at 2 °C under air and MAP was 9 and 13 d respectively. Pseudomonas and H2S producing bacteria were among the dominant spoilage microorganisms under both storage conditions, while Lactic Acid Bacteria (LAB) and Brochothrix thermosphacta were co-dominant with Pseudomonas and H2S producing bacteria under MAP. The traditional CSIs such as TVB-N and TMA-N were increased substantially only at the late stages of storage or after rejection of the products, making them unsuitable for freshness/spoilage monitoring throughout storage. A substantial number of VOCs attributed to microbiological action or chemical activity, were detected including alcohols, aldehydes, ketones, organic acids and esters. The level of microbial origin VOCs such as ethanol, 2-ethyl-1-hexanol, 3-methyl-1-butanol, 2-methyl-1-butanol, 3-methylbutanal, 2-methylbutanal and some ethyl esters increased during storage, suggesting their potential as CSIs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Food Allergies: Understanding Food Labels

    Science.gov (United States)

    ... a few common questions about food label requirements. What foods are labeled? Domestic or imported packaged food is ... allergens found in flavorings, colorings or other additives. What foods aren't labeled? Fresh produce, eggs, fresh meat ...

  16. Ultraviolet sensitivity of Vibrio parahaemolyticus, a causative bacterium of food poisoning

    International Nuclear Information System (INIS)

    Nozu, K.; Ohnishi, T.

    1977-01-01

    A pathogenic strain of Vibrio parahaemolyticus, strain WP1, is about 5 times more sensitive to killing by ultraviolet light than is the non-pathogenic strain WP28, but WP1 cells have an efficient liquid-holding recovery. The cellular DNA of both strains is fragmented shortly after ultraviolet irradiation, but the fragment DNA is converted in a short time to the initial large molecular size in WP28 cells. In WP1 cells, however, the DNA molecules were degraded rapidly without any apparent rejoining in a growth condition. Post-irradiation liquid-holding made the DNA of WP1 cells stable, as supported by the recovery of DNA synthetic activity in these cells. (author)

  17. Influence of food preservation parameters and associated microbiota on production rate, profile and stability of acylated homoserine lactones from food-derived Enterobacteriaceae

    DEFF Research Database (Denmark)

    Flodgaard, Lars; Christensen, Allan Beck; Molin, Søren

    2003-01-01

    Quorum-dependent regulation is mediated by N-acyl-L-homoserine lactones (AHLs) in several Gram-negative bacteria. The production of AHLs has typically been studied using pure bacteria cultures grown in nutrient-rich media at optimal temperature. AHLs are produced in several chill-stored foods...... by Gram-negative bacteria participating in spoilage. As part of our investigation of the role of AHLs in food quality, we studied the AHL production in two Enterobacteriaceae isolated from cold-smoked salmon under growth conditions typical of those found in cold-smoked salmon. We tested the influence......H is approximately 6 and therefore only a low degree of pH-induced turnover is expected to occur in this product. Overall, our study demonstrates that food-derived Enterobacteriaceae produce AHLs of the same type and in the same magnitude when grown under food-relevant conditions as when grown in laboratory media...

  18. Partial characterization of xylanase produced by Caldicoprobacter algeriensis, a new thermophilic anaerobic bacterium isolated from an Algerian hot spring.

    Science.gov (United States)

    Bouacem, Khelifa; Bouanane-Darenfed, Amel; Boucherba, Nawel; Joseph, Manon; Gagaoua, Mohammed; Ben Hania, Wajdi; Kecha, Mouloud; Benallaoua, Said; Hacène, Hocine; Ollivier, Bernard; Fardeau, Marie-Laure

    2014-11-01

    To date, xylanases have expanded their use in many processing industries, such as pulp, paper, food, and textile. This study aimed the production and partial characterization of a thermostable xylanase from a novel thermophilic anaerobic bacterium Caldicoprobacter algeriensis strain TH7C1(T) isolated from a northeast hot spring in Algeria. The obtained results showed that C. algeriensis xylanase seems not to be correlated with the biomass growth profile whereas the maximum enzyme production (140.0 U/ml) was recorded in stationary phase (18 h). The temperature and pH for optimal activities were 70 °C and 11.0, respectively. The enzyme was found to be stable at 50, 60, 70, and 80 °C, with a half-life of 10, 9, 8, and 4 h, respectively. Influence of metal ions on enzyme activity revealed that Ca(+2) enhances greatly the relative activity to 151.3 %; whereas Hg(2+) inhibited significantly the enzyme. At the best of our knowledge, this is the first report on the production of xylanase by the thermophilic bacterium C. algeriensis. This thermo- and alkaline-tolerant xylanase could be used in pulp bleaching process.

  19. Naturally fermented ethnic soybean foods of India

    Directory of Open Access Journals (Sweden)

    Jyoti Prakash Tamang

    2015-03-01

    Full Text Available Kinema, hawaijar, tungrymbai, bekang, aakhone, and peruyaan are naturally fermented ethnic soybean foods of India; they are popular among the Mongolian-origin races in the Eastern Himalayas. Bacillus subtilis is the dominant functional bacterium in all naturally fermented soybean foods of these regions. Although there is a good demand for ethnic fermented soybean foods among local consumers in north-east India, the production is limited to household level. A ready-to-use pulverized starter culture for kinema production can be introduced to kinema-makers or similar sticky fermented soybean foods of north-east India and adapted to local conditions for additional income generation. Ethnic fermented soybeans are one of the major food resources in the Eastern Himalayas; they supplement inexpensive, high-digested plant protein in the local diet with low fat/cholesterol content and high nutritive value as well as antioxidant and other health-promoting properties.

  20. Aspergilli with Neosartorya-type ascospores: heat resistance and effect of sugar concentration on growth and spoilage incidence in berry products.

    Science.gov (United States)

    Berni, Elettra; Tranquillini, Roberta; Scaramuzza, Nicoletta; Brutti, Andrea; Bernini, Valentina

    2017-10-03

    This study focused on four different heat resistant aspergilli: two strains of Aspergillus hiratsukae (≡Neosartorya hiratsukae), one strain of Aspergillus neoglaber (≡Neosartorya glabra), and one strain of Aspergillus thermomutatus (≡Neosartorya pseudofischeri), all isolated from spoiled pasteurized products. Their heat-resistance, the sugar concentration limiting their germination and growth in berry-based media, and a possible relation between the contamination levels of the raw materials used and the spoilage incidence in strawberry jams were assessed. Heat resistance data obtained from thermal death curves showed that the D values of the strains tested ranged between 3.7 and 13.5min at 87°C; 1.5 and 3.5min at 90°C; and 0.3 and 0.4min at 95°C in glucose solution. Similarly, D values ranged between 3.3 and 15.4min at 87°C; 1.3 and 4.3min at 90°C; and 0.3 and 0.6min at 95°C in strawberry-based formulation. For all strains, the corresponding z-values ranged between 5.7 and 8.3°C in glucose solution and from 5.7 to 8.4°C in strawberry formulation. With regard to the limitation of fungal germination and growth in fruit-based media, sucrose concentrations required to avoid growth varied between 45.0 and 55.0% for strawberry medium and between 42.5% and 50.0% for blueberry medium. Spore inactivation was observed below aw 0.88-0.91 for strawberries and aw 0.87-0.90 for blueberries; above 49.7-56.5°Bx for strawberries and 49.6-56.0°Bx for blueberries. The threshold optical refractometric residue proved strain-dependent, but substrate-independent, as for each strain the highest Brix degree value at which germination occurred was the same on both media, despite their different sucrose concentrations. With regard to the relation between contamination of raw materials by heat-resistant mould spores and spoilage incidence on final product, an equation was modelled to estimate the occurrence of fungal spoilage in strawberry jams for low contamination levels (26

  1. Dense populations of a giant sulfur bacterium in Namibian shelf sediments

    DEFF Research Database (Denmark)

    Schulz, HN; Brinkhoff, T.; Ferdelman, TG

    1999-01-01

    A previously unknown giant sulfur bacterium is abundant in sediments underlying the oxygen minimum zone of the Benguela Current upwelling system. The bacterium has a spherical cell that exceeds by up to 100-fold the biovolume of the largest known prokaryotes. On the basis of 16S ribosomal DNA...

  2. A lactic acid bacterium isolated from kimchi ameliorates intestinal inflammation in DSS-induced colitis.

    Science.gov (United States)

    Park, Jin-Soo; Joe, Inseong; Rhee, Paul Dong; Jeong, Choon-Soo; Jeong, Gajin

    2017-04-01

    Some species of lactic acid bacteria have been shown to be beneficial in inflammatory bowel disease (IBD). In the present study, a strain of lactic acid bacterium (Lactobacillus paracasei LS2) was isolated from the Korean food, kimchi, and was shown to inhibit the development of experimental colitis induced by dextran sulfate sodium (DSS). To investigate the role of LS2 in IBD, mice were fed DSS in drinking water for seven days along with LS2 bacteria which were administered intragastrically to some of the mice, while phosphate-buffered saline (PBS) was administered to others (the controls). The administration of LS2 reduced body weight loss and increased survival, and disease activity indexes (DAI) and histological scores indicated that the severity of colitis was significantly reduced. The production of inflammatory cytokines and myeloperoxidase (MPO) activity also decreased. Flow cytometry analysis showed that the number of Th1 (IFN-γ) population cells was significantly reduced in the LS2-administered mice compared with the controls. The administration of LS2 induced the increase of CD4 + FOXP3 + Treg cells, which are responsible for IL-10. Numbers of macrophages (CD11b + F4/80 + ), and neutrophils (CD11b + Gr-1 + ) among lamina propria lymphocytes (LPL) were also reduced. These results indicate that LS2 has an anti-inflammatory effect and ameliorates DSS-induced colitis.

  3. Antioxidant and DNA Damage Protecting Activity of Exopolysaccharides from the Endophytic Bacterium Bacillus cereus SZ1

    Directory of Open Access Journals (Sweden)

    Li Ping Zheng

    2016-02-01

    Full Text Available An endophytic bacterium was isolated from the Chinese medicinal plant Artemisia annua L. The phylogenetic and physiological characterization indicated that the isolate, strain SZ-1, was Bacillus cereus. The endophyte could produce an exopolysaccharide (EPS at 46 mg/L. The 1,1-diphenyl-2-picrylhydracyl (DPPH radical scavenging activity of the EPS reached more than 50% at 3–5 mg/mL. The EPS was also effective in scavenging superoxide radical in a concentration dependent fashion with an EC50 value of 2.6 mg/mL. The corresponding EC50 for scavenging hydroxyl radical was 3.1 mg/mL. Moreover, phenanthroline-copper complex-mediated chemiluminescent emission of DNA damage was both inhibited and delayed by EPS. The EPS at 0.7–1.7 mg/mL also protected supercoiled DNA strands in plasmid pBR322 against scission induced by Fenton-mediated hydroxyl radical. The preincubation of PC12 cells with the EPS prior to H2O2 exposure increased the cell survival and glutathione (GSH level and catalase (CAT activities, and decreased the level of malondialdehyde (MDA and lactate dehydrogenase (LDH activity in a dose-dependent manner, suggesting a pronounced protective effect against H2O2-induced cytotoxicity. Our study indicated that the EPS could be useful for preventing oxidative DNA damage and cellular oxidation in pharmaceutical and food industries.

  4. Encapsulated in silica: genome, proteome and physiology of the thermophilic bacterium Anoxybacillus flavithermus

    Energy Technology Data Exchange (ETDEWEB)

    Saw, Jimmy H [Los Alamos National Laboratory; Mountain, Bruce W [NEW ZEALAND; Feng, Lu [NANKAI UNIV; Omelchenko, Marina V [NCBI/NLM/NIH; Hou, Shaobin [UNIV OF HAWAII; Saito, Jennifer A [UNIV OF HAWAII; Stott, Matthew B [NEW ZEALAND; Li, Dan [NANKAI UNIV; Zhao, Guang [NANKAI UNIV; Wu, Junli [NANKAI UNIV; Galperin, Michael Y [NCBI/NLM/NIH; Koonin, Eugene V [NCBI/NLM/NIH; Makarova, Kira S [NCBI/NLM/NIH; Wolf, Yuri I [NCBI/NLM/NIH; Rigden, Daniel J [UNIV OF LIVERPOOL; Dunfield, Peter F [UNIV OF CALGARY; Wang, Lei [NANKAI UNIV; Alam, Maqsudul [UNIV OF HAWAII

    2008-01-01

    Gram-positive bacteria of the genus Anoxybacillus have been found in diverse thermophilic habitats, such as geothermal hot springs and manure, and in processed foods such as gelatin and milk powder. Anoxybacillus flavithermus is a facultatively anaerobic bacterium found in super-saturated silica solutions and in opaline silica sinter. The ability of A. flavithermus to grow in super-saturated silica solutions makes it an ideal subject to study the processes of sinter formation, which might be similar to the biomineralization processes that occurred at the dawn of life. We report here the complete genome sequence of A. flavithermus strain WK1, isolated from the waste water drain at the Wairakei geothermal power station in New Zealand. It consists of a single chromosome of 2,846,746 base pairs and is predicted to encode 2,863 proteins. In silico genome analysis identified several enzymes that could be involved in silica adaptation and biofilm formation, and their predicted functions were experimentally validated in vitro. Proteomic analysis confirmed the regulation of biofilm-related proteins and crucial enzymes for the synthesis of long-chain polyamines as constituents of silica nanospheres. Microbial fossils preserved in silica and silica sinters are excellent objects for studying ancient life, a new paleobiological frontier. An integrated analysis of the A. flavithermus genome and proteome provides the first glimpse of metabolic adaptation during silicification and sinter formation. Comparative genome analysis suggests an extensive gene loss in the Anoxybacillus/Geobacillus branch after its divergence from other bacilli.

  5. Discovery of a Marine Bacterium Producing 4-Hydroxybenzoate and Its Alkyl Esters, Parabens

    Science.gov (United States)

    Peng, Xue; Adachi, Kyoko; Chen, Choryu; Kasai, Hiroaki; Kanoh, Kaneo; Shizuri, Yoshikazu; Misawa, Norihiko

    2006-01-01

    Chemically synthesized 4-hydroxybenzoate (4HBA) is widely used in the chemical and electrical industries as a material for producing polymers such as those of the liquid crystal type. Its alkyl esters, called parabens, have been the most widely used preservatives by the food and cosmetic industries. We report here for the first time a microorganism, a marine bacterium, which biosynthesizes these petrochemical products. The marine bacterial strain, A4B-17, which was found to belong to the genus Microbulbifer on the basis of its rRNA and gyrB sequences, was isolated from an ascidian in the coastal waters of Palau. Strain A4B-17 was, surprisingly, found to produce 10 mg/liter of 4HBA, together with its butyl (24 mg/liter), heptyl (0.4 mg/liter), and nonyl (6 mg/liter) esters. We therefore characterized 23 other marine bacteria belonging to the genus Microbulbifer, which our institute had previously isolated from various marine environments, and found that these bacteria also produced 4HBA, although with low production levels (less than one-fifth of that produced by A4B-17). We also show that the alkyl esters of 4HBA produced by strain A4B-17 were effective in preventing the growth of yeasts, molds, and gram-positive bacteria. PMID:16885309

  6. Genome analysis of the Anerobic Thermohalophilic bacterium Halothermothrix orenii

    Energy Technology Data Exchange (ETDEWEB)

    Mavromatis, Konstantinos; Ivanova, Natalia; Anderson, Iain; Lykidis, Athanasios; Hooper, Sean D.; Sun, Hui; Kunin, Victor; Lapidus, Alla; Hugenholtz, Philip; Patel, Bharat; Kyrpides, Nikos C.

    2008-11-03

    Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.

  7. A bacterium that degrades and assimilates poly(ethylene terephthalate).

    Science.gov (United States)

    Yoshida, Shosuke; Hiraga, Kazumi; Takehana, Toshihiko; Taniguchi, Ikuo; Yamaji, Hironao; Maeda, Yasuhito; Toyohara, Kiyotsuna; Miyamoto, Kenji; Kimura, Yoshiharu; Oda, Kohei

    2016-03-11

    Poly(ethylene terephthalate) (PET) is used extensively worldwide in plastic products, and its accumulation in the environment has become a global concern. Because the ability to enzymatically degrade PET has been thought to be limited to a few fungal species, biodegradation is not yet a viable remediation or recycling strategy. By screening natural microbial communities exposed to PET in the environment, we isolated a novel bacterium, Ideonella sakaiensis 201-F6, that is able to use PET as its major energy and carbon source. When grown on PET, this strain produces two enzymes capable of hydrolyzing PET and the reaction intermediate, mono(2-hydroxyethyl) terephthalic acid. Both enzymes are required to enzymatically convert PET efficiently into its two environmentally benign monomers, terephthalic acid and ethylene glycol. Copyright © 2016, American Association for the Advancement of Science.

  8. Virtual bacterium colony in 3D image segmentation.

    Science.gov (United States)

    Badura, Pawel

    2018-04-01

    Several heuristic, biologically inspired strategies have been discovered in recent decades, including swarm intelligence algorithms. So far, their application to volumetric imaging data mining is, however, limited. This paper presents a new flexible swarm intelligence optimization technique for segmentation of various structures in three- or two-dimensional images. The agents of a self-organizing colony explore their host, use stigmergy to communicate themselves, and mark regions of interest leading to the object extraction. Detailed specification of the bacterium colony segmentation (BCS) technique in terms of both individual and social behaviour is described in this paper. The method is illustrated and evaluated using several experiments involving synthetic data, computed tomography studies, and ultrasonography images. The obtained results and observations are discussed in terms of parameter settings and potential application of the method in various segmentation tasks. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Antitrypanosomal Alkaloids from the Marine Bacterium Bacillus pumilus

    Directory of Open Access Journals (Sweden)

    Sergio Martínez-Luis

    2012-09-01

    Full Text Available Fractionation of the ethyl acetate extract of the marine bacterium Bacillus pumilus isolated from the black coral Antipathes sp. led to the isolation of five compounds: cyclo-(L-Leu-L-Pro (1, 3-hydroxyacetylindole (2, N-acetyl-b-oxotryptamine (3, cyclo-(L-Phe-L-Pro (4, and 3-formylindole (5. The structures of compounds 1−5 were established by spectroscopic analyses, including HRESITOF-MS and NMR (1H, 13C, HSQC, HMBC and COSY. Compounds 2, 3 and 5 caused the inhibition on the growth of Trypanosoma cruzi (T. cruzi, with IC50 values of 20.6, 19.4 and 26.9 μM, respectively, with moderate cytotoxicity against Vero cells. Compounds 1−5 were found to be inactive when tested against Plasmodium falciparum and Leishmania donovani, therefore showing selectivity against T. cruzi parasites.

  10. Past and Future of Non-Saccharomyces Yeasts: From Spoilage Microorganisms to Biotechnological Tools for Improving Wine Aroma Complexity

    Science.gov (United States)

    Padilla, Beatriz; Gil, José V.; Manzanares, Paloma

    2016-01-01

    It is well established that non-Saccharomyces wine yeasts, considered in the past as undesired or spoilage yeasts, can enhance the analytical composition, and aroma profile of the wine. The contribution of non-Saccharomyces yeasts, including the ability to secret enzymes and produce secondary metabolites, glycerol and ethanol, release of mannoproteins or contributions to color stability, is species- and strain-specific, pointing out the key importance of a clever strain selection. The use of mixed starters of selected non-Saccharomyces yeasts with strains of Saccharomyces cerevisiae represents an alternative to both spontaneous and inoculated wine fermentations, taking advantage of the potential positive role that non-Saccharomyces wine yeast species play in the organoleptic characteristics of wine. In this context mixed starters can meet the growing demand for new and improved wine yeast strains adapted to different types and styles of wine. With the aim of presenting old and new evidences on the potential of non-Saccharomyces yeasts to address this market trend, we mainly review the studies focused on non-Saccharomyces strain selection and design of mixed starters directed to improve primary and secondary aroma of wines. The ability of non-Saccharomyces wine yeasts to produce enzymes and metabolites of oenological relevance is also discussed. PMID:27065975

  11. Dekkera bruxellensis--spoilage yeast with biotechnological potential, and a model for yeast evolution, physiology and competitiveness.

    Science.gov (United States)

    Blomqvist, Johanna; Passoth, Volkmar

    2015-06-01

    Dekkera bruxellensis is a non-conventional yeast normally considered a spoilage organism in wine (off-flavours) and in the bioethanol industry. But it also has potential as production yeast. The species diverged from Saccharomyces cerevisiae 200 mya, before the whole genome duplication. However, it displays similar characteristics such as being Crabtree- and petite positive, and the ability to grow anaerobically. Partial increases in ploidy and promoter rewiring may have enabled evolution of the fermentative lifestyle in D. bruxellensis. On the other hand, it has genes typical for respiratory yeasts, such as for complex I or the alternative oxidase AOX1. Dekkera bruxellensis grows more slowly than S. cerevisiae, but produces similar or greater amounts of ethanol, and very low amounts of glycerol. Glycerol production represents a loss of energy but also functions as a redox sink for NADH formed during synthesis of amino acids and other compounds. Accordingly, anaerobic growth required addition of certain amino acids. In spite of its slow growth, D. bruxellensis outcompeted S. cerevisiae in glucose-limited cultures, indicating a more efficient energy metabolism and/or higher affinity for glucose. This review tries to summarize the latest discoveries about evolution, physiology and metabolism, and biotechnological potential of D. bruxellensis. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  12. Modeling yeast spoilage in cold-filled ready-to-drink beverages with Saccharomyces cerevisiae, Zygosaccharomyces bailii, and Candida lipolytica.

    Science.gov (United States)

    Battey, Alyce Stiles; Duffy, Siobain; Schaffner, Donald W

    2002-04-01

    Mathematical models were developed to predict the probability of yeast spoilage of cold-filled ready-to-drink beverages as a function of beverage formulation. A Box-Behnken experimental design included five variables, each at three levels: pH (2.8, 3.3, and 3.8), titratable acidity (0.20, 0.40, and 0.60%), sugar content (8.0, 12.0, and 16.0 degrees Brix), sodium benzoate concentration (100, 225, and 350 ppm), and potassium sorbate concentration (100, 225, and 350 ppm). Duplicate samples were inoculated with a yeast cocktail (100 microl/50 ml) consisting of equal proportions of Saccharomyces cerevisiae, Zygosaccharomyces bailii, and Candida lipolytica (approximately 5.0 x 10(4) CFU/ml each). The inoculated samples were plated on malt extract agar after 0, 1, 2, 4, 6, and 8 weeks. Logistic regression was used to create the predictive models. The pH and sodium benzoate and potassium sorbate concentrations were found to be significant factors controlling the probability of yeast growth. Interaction terms for pH and each preservative were also significant in the predictive model. Neither the titratable acidity nor the sugar content of the model beverages was a significant predictor of yeast growth in the ranges tested.

  13. Antibacterial Activity of Ethyl Acetate the Extract of Noni Fruit (Morinda citrifolia L.) Against Bacterial Spoilage in Fish

    Science.gov (United States)

    Nugraheni, E. R.; Adriani, G. R.; Munawaroh, H.

    2017-04-01

    Noni fruit (Morinda citrifolia L.) contains compounds that have potential as antibacterial agent. Antibacterial compounds produced noni fruit (M. citrifolia L.) can inhibit bacterial growth. This study was conducted to test the antibacterial activity of ethyl acetate extract of noni fruit (M. citrifolia L.) against spoilage bacterial in fish. Pseudomonas aeruginosa, Bacillus cereus, Escherichia coli, Klebsiella oxytoca, and Enterobacter aerogenes isolates and examine antibacterial phytochemical profile. Extraction of noni compounds was done by maceration, followed by partition with ethyl acetate to obtain the soluble and insoluble ethyl acetate fraction. Previews result show that the ethyl acetate extract had very strong activity. Extraction process continued by separation and isolation used preparative thin layer chromatography method, so that obtained five isolates and mark them as A, B, C, D and E. Antibacterial activity assay performed on isolates A, B, C, D, and E with 20 and 30% concentration. The test results showed that isolates A could not be inhibit the growth of bacteria, isolates B, C, D, and E has antibacterial activity with weak to strong inhibition. Isolate B had the greatest inhibition activity against the B. cereus, whereas isolates E had the greatest inhibition activity against P. aeroginosa. MIC (Minimum Inhibitor Concentration) and MBC (Minimum Bactericidal Concentration) test result showed that MIC and MBC values could not be determined. Analysis of compounds by TLC showed that isolate B suspected contains coumarin or flavonoids compounds that have antibacterial activity.

  14. Mold spoilage of bread and its biopreservation: A review of current strategies for bread shelf life extension.

    Science.gov (United States)

    Axel, Claudia; Zannini, Emanuele; Arendt, Elke K

    2017-11-02

    Microbial spoilage of bread and the consequent waste problem causes large economic losses for both the bakery industry and the consumer. Furthermore the presence of mycotoxins due to fungal contamination in cereals and cereal products remains a significant issue. The use of conventional chemical preservatives has several drawbacks, necessitating the development of clean-label alternatives. In this review, we describe current research aiming to extend the shelf life of bread through the use of more consumer friendly and ecologically sustainable preservation techniques as alternatives to chemical additives. Studies on the in situ-production/-expression of antifungal compounds are presented, with special attention given to recent developments over the past decade. Sourdough fermented with antifungal strains of lactic acid bacteria (LAB) is an area of increasing focus and serves as a high-potential biological ingredient to produce gluten-containing and gluten-free breads with improved nutritional value, quality and safety due to shelf-life extension, and is in-line with consumer's demands for more products containing less additives. Other alternative biopreservation techniques include the utilization of antifungal peptides, ethanol and plant extracts. These can be added to bread formulations or incorporated in antimicrobial films for active packaging (AP) of bread. This review outlines recent progress that has been made in the area of bread biopreservation and future perspectives in this important area.

  15. Evaluation of treatments with hot water, chemicals and ventilated containers to reduce microbial spoilage in irradiated potatoes

    International Nuclear Information System (INIS)

    Shirsat, S.G.; Thomas, P.; Nair, P.M.

    1991-01-01

    Potatoes irradiated to control sprouting were dipped in: hot water (56°C, 5 min; 52°C, 10, 15 and 20 min); cold (25°C, 5 min) or hot (56°C, 5 min) salicylic acid (1000 and 2000 ppm); or sodium hypochlorite (0.1 and 0.2%, 5 min); or dusted with salicylic acid (1 and 2%), to try to reduce the incidence of bacterial soft rot (Erwinia sp.) during controlled temperature (10°C, 15°C) and ambient temperature (20–34°C) storage. All treatments, particularly hot water and hot salicylic acid dip, increased microbial spoilage, possibly as a result of handling damage during the treatments combined with the inhibition of wound periderm formation as a result of irradiation. Storing irradiated tubers in well ventilated containers reduced soft rot compared to storing them in sacks and after 6 months storage at 10, 15 and 20–34°C, 95, 90 and 77% respectively were healthy and marketable. (author)

  16. Production of reuterin in a fermented milk product by Lactobacillus reuteri: Inhibition of pathogens, spoilage microorganisms, and lactic acid bacteria.

    Science.gov (United States)

    Ortiz-Rivera, Y; Sánchez-Vega, R; Gutiérrez-Méndez, N; León-Félix, J; Acosta-Muñiz, C; Sepulveda, D R

    2017-06-01

    We assessed the antimicrobial activity of reuterin produced in vitro in glycerol aqueous solutions in situ by Lactobacillus reuteri ATCC 53608 as part of a fermented milk product against starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus), spoilage (Penicillium expansum), pathogenic (Staphylococcus aureus Salmonella enterica ssp. enterica, and Listeria monocytogenes), and pathogen surrogate (Escherichia coli DH5α) microorganisms. We also assayed the influence of cold storage (28 d at 4°C) and reuterin on the color and rheology of the fermented milk product. We obtained maximum reuterin concentrations of 107.5 and 33.97 mM in glycerol aqueous solution and fermented milk product, respectively. Reuterin was stable throughout its refrigerated shelf life. Gram-positive microorganisms were more resistant to reuterin than gram-negative microorganisms. Penicillium expansum and Lactobacillus reuteri ATCC 53608 survived at concentrations up to 10 and 8.5 mM, respectively. Escherichia coli DH5α was the most sensitive to reuterin (0.9 mM). The presence of reuterin did not cause relevant changes in the quality parameters of the fermented milk product, including pH, acidity, soluble solids, color, and rheological aspects (storage and loss moduli and viscosity). This study demonstrated the viability of using Lactobacillus reuteri ATCC 53608 as a biopreservative in a fermented milk product through reuterin synthesis, without drastically modifying its quality parameters. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  17. Past and future of non-Saccharomyces yeasts: from spoilage microorganisms to biotechnological tools for improving wine aroma complexity

    Directory of Open Access Journals (Sweden)

    Beatriz ePadilla

    2016-03-01

    Full Text Available It is well established that non-Saccharomyces wine yeasts, considered in the past as undesired or spoilage yeasts, can enhance the analytical composition and aroma profile of the wine. The contribution of non-Saccharomyces yeasts, including the ability to secret enzymes and produce secondary metabolites, glycerol and ethanol, release of mannoproteins or contributions to color stability, is species- and strain-specific, pointing out the key importance of a clever strain selection. The use of mixed starters of selected non-Saccharomyces yeasts with strains of Saccharomyces cerevisiae represents an alternative to both spontaneous and inoculated wine fermentations, taking advantage of the potential positive role that non-Saccharomyces wine yeast species play in the organoleptic characteristics of wine. In this context mixed starters can meet the growing demand for new and improved wine yeast strains adapted to different types and styles of wine. With the aim of presenting old and new evidences on the potential of non-Saccharomyces yeasts to address this market trend, we mainly review the studies focused on non-Saccharomyces strain selection and design of mixed starters directed to improve primary and secondary aroma of wines. The ability of non-Saccharomyces wine yeasts to produce enzymes and metabolites of oenological relevance is also discussed.

  18. Live-Cell Imaging Tool Optimization To Study Gene Expression Levels and Dynamics in Single Cells of Bacillus cereus

    NARCIS (Netherlands)

    Eijlander, Robyn T.; Kuipers, Oscar P.

    Single-cell methods are a powerful application in microbial research to study the molecular mechanism underlying phenotypic heterogeneity and cell-to-cell variability. Here, we describe the optimization and application of single-cell time-lapse fluorescence microscopy for the food spoilage bacterium

  19. The Circular Bacteriocins Gassericin A and Circularin A

    NARCIS (Netherlands)

    Kawai, Yasushi; Kemperman, Rober; Kok, Jan; Saito, Tadao

    2004-01-01

    Gassericin A, a bacteriocin produced by Lactobacillus gasseri LA39, shows antibacterial activity against a number of Gram-positive food-borne pathogenic bacteria. Circularin A produced by Clostridium beijerinckii ATCC25752 is active against C. tyrobutyricum, a known cheese-spoilage bacterium. Both

  20. Food allergy

    Directory of Open Access Journals (Sweden)

    Youngshin Han

    2012-05-01

    Full Text Available Food allergy is an important public health problem affecting 5% of infants and children in Korea. Food allergy is defined as an immune response triggered by food proteins. Food allergy is highly associated with atopic dermatitis and is one of the most common triggers of potentially fatal anaphylaxis in the community. Sensitization to food allergens can occur in the gastrointestinal tract (class 1 food allergy or as a consequence of cross reactivity to structurally homologous inhalant allergens (class 2 food allergy. Allergenicity of food is largely determined by structural aspects, including cross-reactivity and reduced or enhanced allergenicity with cooking that convey allergenic characteristics to food. Management of food allergy currently focuses on dietary avoidance of the offending foods, prompt recognition and treatment of allergic reactions, and nutritional support. This review includes definitions and examines the prevalence and management of food allergies and the characteristics of food allergens.