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.

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."

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.

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.

Potential spoilage yeasts in winery environments: Characterization and proteomic analysis of Trigonopsis cantarellii.

Science.gov (United States)

Portugal, Cauré; Pinto, Luís; Ribeiro, Miguel; Tenorio, Carmen; Igrejas, Gilberto; Ruiz-Larrea, Fernanda

2015-10-01

Wine microbiota is complex and includes a wide diversity of yeast species. Few of them are able to survive under the restrictive conditions of dry red wines. In our study we detected and identified seven yeast species of the order Saccharomycetales that can be considered potential spoilers of wines due to physiological traits such as acidogenic metabolism and off-odor generation: Arthroascus schoenii, Candida ishiwadae, Meyerozyma guilliermondii, Pichia holstii, Pichia manshurica, Trigonopsis cantarellii, and Trigonopsis variabilis. Based on the prevalence of T. cantarellii isolates in the wine samples of our study, we further characterized this species, determined molecular and phenotypic features, and performed a proteomic analysis to identify differentially expressed proteins at mid-exponential growth phase in the presence of ethanol in the culture broth. This yeast species is shown to be able to grow in the presence of ethanol by expressing heat shock proteins (Hsp70, Hsp71) and a DNA damage-related protein (Rad24), and to be able to confer spoilage characteristics on wine. Copyright © 2015 Elsevier B.V. All rights reserved.

Predicting and preventing mold spoilage of food products.

Science.gov (United States)

Dagnas, Stéphane; Membré, Jeanne-Marie

2013-03-01

This article is a review of how to quantify mold spoilage and consequently shelf life of a food product. Mold spoilage results from having a product contaminated with fungal spores that germinate and form a visible mycelium before the end of the shelf life. The spoilage can be then expressed as the combination of the probability of having a product contaminated and the probability of mold growth (germination and proliferation) up to a visible mycelium before the end of the shelf life. For products packed before being distributed to the retailers, the probability of having a product contaminated is a function of factors strictly linked to the factory design, process, and environment. The in-factory fungal contamination of a product might be controlled by good manufacturing hygiene practices and reduced by particular processing practices such as an adequate air-renewal system. To determine the probability of mold growth, both germination and mycelium proliferation can be mathematically described by primary models. When mold contamination on the product is scarce, the spores are spread on the product and more than a few spores are unlikely to be found at the same spot. In such a case, models applicable for a single spore should be used. Secondary models can be used to describe the effect of intrinsic and extrinsic factors on either the germination or proliferation of molds. Several polynomial models and gamma-type models quantifying the effect of water activity and temperature on mold growth are available. To a lesser extent, the effect of pH, ethanol, heat treatment, addition of preservatives, and modified atmospheres on mold growth also have been quantified. However, mold species variability has not yet been properly addressed, and only a few secondary models have been validated for food products. Once the probability of having mold spoilage is calculated for various shelf lives and product formulations, the model can be implemented as part of a risk management

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�

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®

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.

Microbiological spoilage of fish and fish products

DEFF Research Database (Denmark)

Gram, Lone; Huss, Hans Henrik

1996-01-01

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...... 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......- positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish...

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

Microbiological spoilage of fish and fish products.

Science.gov (United States)

Gram, L; Huss, H H

1996-11-01

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 biochemical indicators of spoilage. Shewanella 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-positive bacteria are likely spoilers of CO2 packed fish from fresh or tropical waters. Fish products with high salt contents may spoil due to growth of halophilic bacteria (salted fish) or growth of anaerobic bacteria and yeasts (barrel salted fish). Whilst the spoilage of fresh and highly salted fish is well understood, much less is known about spoilage of lightly preserved fish products. It is concluded that the spoilage is probably caused by lactic acid bacteria, certain psychotrophic Enterobacteriaceae and/or Photobacterium phosphoreum. However, more work is needed in this area.

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

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

Production of Food Grade Yeasts

Directory of Open Access Journals (Sweden)

Argyro Bekatorou

2006-01-01

Full Text Available Yeasts have been known to humans for thousands of years as they have been used in traditional fermentation processes like wine, beer and bread making. Today, yeasts are also used as alternative sources of high nutritional value proteins, enzymes and vitamins, and have numerous applications in the health food industry as food additives, conditioners and flavouring agents, for the production of microbiology media and extracts, as well as livestock feeds. Modern scientific advances allow the isolation, construction and industrial production of new yeast strains to satisfy the specific demands of the food industry. Types of commercial food grade yeasts, industrial production processes and raw materials are highlighted. Aspects of yeast metabolism, with respect to carbohydrate utilization, nutritional aspects and recent research advances are also discussed.

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.

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

MALDI-TOF MS as a tool to identify foodborne yeasts and yeast-like fungi.

Science.gov (United States)

Quintilla, Raquel; Kolecka, Anna; Casaregola, Serge; Daniel, Heide M; Houbraken, Jos; Kostrzewa, Markus; Boekhout, Teun; Groenewald, Marizeth

2018-02-02

Since food spoilage by yeasts causes high economic losses, fast and accurate identifications of yeasts associated with food and food-related products are important for the food industry. In this study the efficiency of the matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to identify food related yeasts was evaluated. A CBS in-house MALDI-TOF MS database was created and later challenged with a blinded test set of 146 yeast strains obtained from food and food related products. Ninety eight percent of the strains were correctly identified with log score values>1.7. One strain, Mrakia frigida, gained a correct identification with a score value1.7. Ambiguous identifications were observed due to two incorrect reference mass spectra's found in the commercial database BDAL v.4.0, namely Candida sake DSM 70763 which was re-identified as Candida oleophila, and Candida inconspicua DSM 70631 which was re-identified as Pichia membranifaciens. MALDI-TOF MS can distinguish between most of the species, but for some species complexes, such as the Kazachstania telluris and Mrakia frigida complexes, MALDI-TOF MS showed limited resolution and identification of sibling species was sometimes problematic. Despite this, we showed that the MALDI-TOF MS is applicable for routine identification and validation of foodborne yeasts, but a further update of the commercial reference databases is needed. Copyright © 2017 Elsevier B.V. All rights reserved.

Yeasts Diversity in Fermented Foods and Beverages

Science.gov (United States)

Tamang, Jyoti Prakash; Fleet, Graham H.

People across the world have learnt to culture and use the essential microorganisms for production of fermented foods and alcoholic beverages. A fermented food is produced either spontaneously or by adding mixed/pure starter culture(s). Yeasts are among the essential functional microorganisms encountered in many fermented foods, and are commercially used in production of baker's yeast, breads, wine, beer, cheese, etc. In Asia, moulds are predominant followed by amylolytic and alcohol-producing yeasts in the fermentation processes, whereas in Africa, Europe, Australia and America, fermented products are prepared exclusively using bacteria or bacteria-yeasts mixed cultures. This chapter would focus on the varieties of fermented foods and alcoholic beverages produced by yeasts, their microbiology and role in food fermentation, widely used commercial starters (pilot production, molecular aspects), production technology of some common commercial fermented foods and alcoholic beverages, toxicity and food safety using yeasts cultures and socio-economy

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.

Control of Microbiological Spoilage of Food by Irradiation

Energy Technology Data Exchange (ETDEWEB)

Farkas, J. [Central Food Research Institute, Budapest (Hungary)

1978-04-15

Papers published from 1973 to 1977 in the field of radiation control of microbiological spoilage are reviewed, grouping the subjects according to the type of process and food treated. Various laboratories from 33 countries have recently published data on the subject, radurization of dates, prepackaged vegetables, wet grains, bread, various meats and meat products being reported. The most widespread research activities could be observed in the field of radurization of fish and marine products (shellfish, shrimps). Radiation decontamination of dry food ingredients (enzyme preparates, protein preparates, starch, spices) and cork stoppers was studied in various laboratories. Radappertization research of several animal-protein foods has made remarkable progress and the minimal dose requirements are well established. Combination of radiation treatment with other antimicrobial agents (salt, preservatives, heat, etc.) has been investigated by many laboratories. Foods involved in these investigations were bread, several tropical and subtropical fruits, apple juice, groundnuts, fish fillets and shrimps, but a considerable part of the data relate to model systems. A better understanding of the synergistic effect will require additional knowledge and the continuation of long-range research and development in the field of combined treatments is recommended. (author)

Control of microbiological spoilage of food by irradiation

International Nuclear Information System (INIS)

Farkas, J.

1978-01-01

Papers published from 1973 to 1977 in the field of radiation control of microbiological spoilage are reviewed, grouping the subjects according to the type of process and food treated. Various laboratories from 33 countries have recently published data on the subject, radurization of dates, prepackaged vegetables, wet grains, bread, various meats and meat products being reported. The most widespread research activities could be observed in the field of radurization of fish and marine products (shellfish, shrimps). Radiation decontamination of dry food ingredients (enzyme preparates, protein preparates, starch, spices) and cork stoppers was studied in various laboratories. Radappertization research of several animal-protein foods has made remarkable progress and the minimal dose requirements are well established. Combination of radiation treatment with other antimicrobial agents (salt, preservatives, heat, etc.) has been investigated by many laboratories. Foods involved in these investigations were bread, several tropical and subtropical fruits, apple juice, groundnuts, fish fillets and shrimps, but a considerable part of the data relate to model systems. A better understanding of the synergistic effect will require additional knowledge and the continuation of long-range research and development in the field of combined treatments is recommended. (author)

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

Investigation of Antibacterial Properties of Yeast Strains Isolated from Iranian Richal and Traditional Dairy Products in Armenia

Directory of Open Access Journals (Sweden)

F Karimpour

2016-09-01

Full Text Available Background & aim:The use of bio preservative or strains as sources are interesting for food bioprocessing technologist,   and is one of the latest methods to increase the shelf life of food by the health authorities . The present study aimed to investigate the antibacterial activity of supernatants of yeasts isolated from Richal as a traditional dairy product and fermented dairy products in Armenia. Methods: In the present experimental study, the purified supernatant of 77 strains of Armenian yeast products and 12 strains from Iranian Richal were isolated. The purified supernatant were tested against three strains as food spoilages bacteria includes: B. subtilis 17-89, B. Thuringensis17-89, S.typhimuium G-38 , on 3media in 2 condition as aerobic and anaerobic. The inhibition zone of the supernatant were measured   and reported as antibacterial activity. Data were analyzed using statistical tests. Result: A total of 89 strains of yeasts, three species of Rachel and 9 strains of Armenian products (13.5% percent had demonstrated antibacterial activity. T86 strains of Armenian yeasts and FA1 (25 of Rachel had shown more ZOI and antibacterial activity on three media at both aerobic and anaerobic conditions. Comparing the mean of ZOI upon three corruption factors, Rachel strains were significantly different (p <0.05. The highest and lowest effect was observed on Bacillus subtilis effect and Salmonella typhimurium respectively. Conclusion: The results indicated that the yeast strains isolated in anaerobic and aerobic conditions on spoilage bacteria had antibacterial activity effect. Thus, it could be concluded that adding the yeast or its supernatant to food as a bio preservative, may introduce a operative product to the food industry.

The wine and beer yeast Dekkera bruxellensis.

Science.gov (United States)

Schifferdecker, Anna Judith; Dashko, Sofia; Ishchuk, Olena P; Piškur, Jure

2014-09-01

Recently, the non-conventional yeast Dekkera bruxellensis has been gaining more and more attention in the food industry and academic research. This yeast species is a distant relative of Saccharomyces cerevisiae and is especially known for two important characteristics: on the one hand, it is considered to be one of the main spoilage organisms in the wine and bioethanol industry; on the other hand, it is 'indispensable' as a contributor to the flavour profile of Belgium lambic and gueuze beers. Additionally, it adds to the characteristic aromatic properties of some red wines. Recently this yeast has also become a model for the study of yeast evolution. In this review we focus on the recently developed molecular and genetic tools, such as complete genome sequencing and transformation, to study and manipulate this yeast. We also focus on the areas that are particularly well explored in this yeast, such as the synthesis of off-flavours, yeast detection methods, carbon metabolism and evolutionary history. © 2014 The Authors. Yeast published by John Wiley & Sons, Ltd.

Antimicrobial activity of yeasts against some pathogenic bacteria

Directory of Open Access Journals (Sweden)

Gamal Younis

2017-08-01

Full Text Available Aim: This study was designed to isolate and identify yeast species from milk and meat products, and to test their antimicrobial activity against some bacterial species. Materials and Methods: A total of 160 milk and meat products samples were collected from random sellers and super markets in New Damietta city, Damietta, Egypt. Samples were subjected to yeast isolation procedures and tested for its antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. In addition, all yeast species isolates were subjected to polymerase chain reaction (PCR for detection of khs (kievitone hydratase and pelA (pectate degrading enzyme genes. Results: The recovery rate of yeasts from sausage was 20% (2/10 followed by kareish cheese, processed cheese, and butter 10% (1/10 each as well as raw milk 9% (9/100, and fruit yoghurt 30% (6/20. Different yeast species were recovered, namely, Candida kefyr (5 isolates, Saccharomyces cerevisiae (4 isolates, Candida intermedia (3 isolates, Candida tropicalis (2 isolates, Candida lusitaniae (2 isolates, and Candida krusei (1 isolate. khs gene was detected in all S. cerevisiae isolates, however, pelA gene was not detected in all identified yeast species. Antimicrobial activity of recovered yeasts against the selected bacterial species showed high activity with C. intermedia against S. aureus and E. coli, C. kefyr against E. coli, and C. lusitaniae against S. aureus. Moderate activities were obtained with C. tropicalis, C. lusitaniae, and S. cerevisiae against E. coli; meanwhile, all the tested yeasts revealed a very low antimicrobial activity against P. aeruginosa. Conclusion: The obtained results confirmed that some kinds of yeasts have the ability to produce antimicrobial compounds that could inhibit some pathogenic and spoilage bacteria and these antimicrobial activity of yeasts enables them to be one of the novel agents in controlling spoilage of food.

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.

Rapid measurement of meat spoilage using fluorescence spectroscopy

Science.gov (United States)

Wu, Binlin; Dahlberg, Kevin; Gao, Xin; Smith, Jason; Bailin, Jacob

2017-02-01

Food spoilage is mainly caused by microorganisms, such as bacteria. In this study, we measure the autofluorescence in meat samples longitudinally over a week in an attempt to develop a method to rapidly detect meat spoilage using fluorescence spectroscopy. Meat food is a biological tissue, which contains intrinsic fluorophores, such as tryptophan, collagen, nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) etc. As meat spoils, it undergoes various morphological and chemical changes. The concentrations of the native fluorophores present in a sample may change. In particular, the changes in NADH and FAD are associated with microbial metabolism, which is the most important process of the bacteria in food spoilage. Such changes may be revealed by fluorescence spectroscopy and used to indicate the status of meat spoilage. Therefore, such native fluorophores may be unique, reliable and nonsubjective indicators for detection of spoiled meat. The results of the study show that the relative concentrations of all above fluorophores change as the meat samples kept in room temperature ( 19° C) spoil. The changes become more rapidly after about two days. For the meat samples kept in a freezer ( -12° C), the changes are much less or even unnoticeable over a-week-long storage.

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...

Testing nano-silver food packaging to evaluate silver migration and food spoilage bacteria on chicken meat.

Science.gov (United States)

Gallocchio, Federica; Cibin, Veronica; Biancotto, Giancarlo; Roccato, Anna; Muzzolon, Orietta; Carmen, Losasso; Simone, Belluco; Manodori, Laura; Fabrizi, Alberto; Patuzzi, Ilaria; Ricci, Antonia

2016-06-01

Migration of nanomaterials from food containers into food is a matter of concern because of the potential risk for exposed consumers. The aims of this study were to evaluate silver migration from a commercially available food packaging containing silver nanoparticles into a real food matrix (chicken meat) under plausible domestic storage conditions and to test the contribution of such packaging to limit food spoilage bacteria proliferation. Chemical analysis revealed the absence of silver in chicken meatballs under the experimental conditions in compliance with current European Union legislation, which establishes a maximum level of 0.010 mg kg(-1) for the migration of non-authorised substances through a functional barrier (Commission Regulation (EU) No. 10/2011). On the other hand, microbiological tests (total microbial count, Pseudomonas spp. and Enterobacteriaceae) showed no relevant difference in the tested bacteria levels between meatballs stored in silver-nanoparticle plastic bags or control bags. This study shows the importance of testing food packaging not only to verify potential silver migration as an indicator of potential nanoparticle migration, but also to evaluate the benefits in terms of food preservation so as to avoid unjustified usage of silver nanoparticles and possible negative impacts on the environment.

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.

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.

Outlining a future for non-Saccharomyces yeasts: selection of putative spoilage wine strains to be used in association with Saccharomyces cerevisiae for grape juice fermentation.

Science.gov (United States)

Domizio, Paola; Romani, Cristina; Lencioni, Livio; Comitini, Francesca; Gobbi, Mirko; Mannazzu, Ilaria; Ciani, Maurizio

2011-06-30

The use of non-Saccharomyces yeasts that are generally considered as spoilage yeasts, in association with Saccharomyces cerevisiae for grape must fermentation was here evaluated. Analysis of the main oenological characteristics of pure cultures of 55 yeasts belonging to the genera Hanseniaspora, Pichia, Saccharomycodes and Zygosaccharomyces revealed wide biodiversity within each genus. Moreover, many of these non-Saccharomyces strains had interesting oenological properties in terms of fermentation purity, and ethanol and secondary metabolite production. The use of four non-Saccharomyces yeasts (one per genus) in mixed cultures with a commercial S. cerevisiae strain at different S. cerevisiae/non-Saccharomyces inoculum ratios was investigated. This revealed that most of the compounds normally produced at high concentrations by pure cultures of non-Saccharomyces, and which are considered detrimental to wine quality, do not reach threshold taste levels in these mixed fermentations. On the other hand, the analytical profiles of the wines produced by these mixed cultures indicated that depending on the yeast species and the S. cerevisiae/non-Saccharomyces inoculum ratio, these non-Saccharomyces yeasts can be used to increase production of polysaccharides and to modulate the final concentrations of acetic acid and volatile compounds, such as ethyl acetate, phenyl-ethyl acetate, 2-phenyl ethanol, and 2-methyl 1-butanol. Copyright © 2011 Elsevier B.V. All rights reserved.

Typing and virulence factors of food-borne Candida spp. isolates.

Science.gov (United States)

Rajkowska, Katarzyna; Kunicka-Styczyńska, Alina

2018-08-20

Food-borne yeasts, excluding yeasts used as starter cultures, are commonly considered as food spoilage microorganisms. However, the incidence of non-C. albicans Candida (NCAC) infections has increased considerably over the past two decades. Although 15 Candida species are frequently identified as pathogens, a threat to human from food-borne Candida is poorly recognized. In the present study food-borne NCAC were characterized for the virulence factors, known to be associated with yeast pathogenicity. All food-borne strains in planktonic forms and 89% in biofilm structures represented biotypes established for C. albicans, and 61% demonstrated hemolytic activity. 56-94% of food-borne isolates formed biofilms on glass and biomaterials at a level comparable to clinical C. albicans. Nine out of eighteen tested food-borne NCAC strains (C. krusei, C. lusitaniae, C. famata, C. colliculosa, C. parapsilosis, C. tropicalis) showed similarity to clinical C. albicans in terms of their biotypes and the tested virulence factors, allocating them in a group of risk of potential pathogens. However, their capacity to grow at 37 °C seems to be the preliminary criterion in the study of potential virulence of food-borne yeasts. Copyright © 2018 Elsevier B.V. All rights reserved.

Occurrence and function of yeasts in Asian indigenous fermented foods

NARCIS (Netherlands)

Aidoo, K.E.; Nout, M.J.R.; Sarkar, P.K.

2006-01-01

In the Asian region, indigenous fermented foods are important in daily life. In many of these foods, yeasts are predominant and functional during the fermentation. The diversity of foods in which yeasts predominate ranges from leavened bread-like products such as nan and idli, to alcoholic beverages

Diversity and killer activity of yeasts in Malaysian fermented food samples.

Science.gov (United States)

Lim, S L; Tay, S T

2011-08-01

The biodiversity and the killer activity of yeasts isolated from various types of fermented food in Malaysia were investigated in this study. Of 252 yeasts isolated from 48 fermented food samples in this study, 19 yeast species were identified based on sequence analysis of the ITS1-5.8S-ITS2 partial fragments of the yeasts. A total of 29 (11.5%) of the yeast isolates demonstrated killer activity to at least one Candida species tested in this study; including 22 isolates of Trichosporon asahii, 4 isolates of Pichia anomala, and one isolate each of Pichia norvegensis, Pichia fermentans and Issatchenkia orientalis, respectively. The presence of killer yeasts reflects antagonism that occurs during microbial interaction in the fermented food, whereby certain yeasts produce killer toxins and possibly other toxic substances in competition for limited nutrients and space. The anti-Candida activity demonstrated by killer yeasts in this study should be further explored for development of alternative therapy against candidiasis.

Eucalyptus essential oil as a natural food preservative: in vivo and in vitro antiyeast potential.

Science.gov (United States)

Tyagi, Amit Kumar; Bukvicki, Danka; Gottardi, Davide; Tabanelli, Giulia; Montanari, Chiara; Malik, Anushree; Guerzoni, Maria Elisabetta

2014-01-01

In this study, the application of eucalyptus essential oil/vapour as beverages preservative is reported. The chemical composition of eucalyptus oil was determined by gas chromatography-mass spectrometry (GC-MS) and solid phase microextraction GC-MS (SPME/GC-MS) analyses. GC-MS revealed that the major constituents were 1,8-cineole (80.5%), limonene (6.5%), α-pinene (5%), and γ-terpinene (2.9%) while SPME/GC-MS showed a relative reduction of 1,8-cineole (63.9%) and an increase of limonene (13.8%), α-pinene (8.87%), and γ-terpinene (3.98%). Antimicrobial potential of essential oil was initially determined in vitro against 8 different food spoilage yeasts by disc diffusion, disc volatilization, and microdilution method. The activity of eucalyptus vapours was significantly higher than the eucalyptus oil. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.56 to 4.50 mg/mL and from 1.13 to 9 mg/mL, respectively. Subsequently, the combined efficacy of essential oil and thermal treatment were used to evaluate the preservation of a mixed fruit juice in a time-dependent manner. These results suggest eucalyptus oil as a potent inhibitor of food spoilage yeasts not only in vitro but also in a real food system. Currently, this is the first report that uses eucalyptus essential oil for fruit juice preservation against food spoiling yeast.

Probiotic properties of yeasts occurring in fermented food and beverages

DEFF Research Database (Denmark)

Jespersen, Lene

Besides being able to improve the quality and safety of many fermented food and beverages some yeasts offer a number of probiotic traits. Especially a group of yeast referred to as "Saccharomyces boulardii", though taxonomically belonging to Saccharomyces cerevisiae, has been claimed to have...... probiotic properties. Besides, yeasts naturally occurring globally in food and beverages will have traits that might have a positive impact on human health....

Spent yeast as natural source of functional food additives

Science.gov (United States)

Rakowska, Rita; Sadowska, Anna; Dybkowska, Ewa; Świderski, Franciszek

Spent yeasts are by-products arising from beer and wine production which over many years have been chiefly used as feed additives for livestock. They contain many valuable and bioactive substances which has thereby generated much interest in their exploitation. Up till now, the main products obtained from beer-brewing yeasts are β-glucans and yeast extracts. Other like foodstuffs include dried brewer’s yeast, where this is dried and the bitterness removed to be fit for human consumption as well as mannan-oligosaccharides hitherto used in the feed industry. β-glucans constitute the building blocks of yeast cell walls and can thus be used in human nutrition as dietary supplements or serving as food additives in functional foods. β-glucans products obtained via post-fermentation of beer also exhibit a high and multi-faceted biological activity where they improve the blood’s lipid profile, enhance immunological status and have both prebiotic and anti-oxidant properties. Yeast extracts are currently being used more and more to enhance flavour in foodstuffs, particularly for meat and its products. Depending on how autolysis is carried out, it is possible to design extracts of various meat flavours characteristic of specific meats. Many different flavour profiles can be created which may be additionally increased in combination with vegetable extracts. Within the food market, yeast extracts can appear in various guises such as liquids, pastes or powders. They all contain significant amounts of glutamic acid, 5’-GMP and 5’-IMP nucleotides together with various amino acids and peptides that act synergistically for enhancing the flavour of foodstuff products. Recent studies have demonstrated additional benefits of yeast extracts as valuable sources of amino acids and peptides which can be used in functional foods and dietary supplements. These products possess GRAS status (Generally Recognised As Safe) which thereby also adds further as to why they should be used

PCR detection of thermophilic spore-forming bacteria involved in canned food spoilage.

Science.gov (United States)

Prevost, S; Andre, S; Remize, F

2010-12-01

Thermophilic bacteria that form highly heat-resistant spores constitute an important group of spoilage bacteria of low-acid canned food. A PCR assay was developed in order to rapidly trace these bacteria. Three PCR primer pairs were designed from rRNA gene sequences. These primers were evaluated for the specificity and the sensitivity of detection. Two primer pairs allowed detection at the species level of Geobacillus stearothermophilus and Moorella thermoacetica/thermoautrophica. The other pair allowed group-specific detection of anaerobic thermophilic bacteria of the genera Thermoanaerobacterium, Thermoanaerobacter, Caldanerobium and Caldanaerobacter. After a single enrichment step, these PCR assays allowed the detection of 28 thermophiles from 34 cans of spoiled low-acid food. In addition, 13 ingredients were screened for the presence of these bacteria. This PCR assay serves as a detection method for strains able to spoil low-acid canned food treated at 55°C. It will lead to better reactivity in the canning industry. Raw materials and ingredients might be qualified not only for quantitative spore contamination, but also for qualitative contamination by highly heat-resistant spores.

Evaluation of five essential oils from aromatic plants of Cameroon for controlling food spoilage and mycotoxin producing fungi.

Science.gov (United States)

Nguefack, J; Leth, V; Amvam Zollo, P H; Mathur, S B

2004-08-01

Five essential oils (EO) extracted from Cymbopogon citratus, Monodora myristica, Ocimum gratissimum, Thymus vulgaris and Zingiber officinale were investigated for their inhibitory effect against three food spoilage and mycotoxin producing fungi, Fusarium moniliforme, Aspergillus flavus and Aspergillus fumigatus. Five strains of each fungus were tested. The agar dilution technique was used to determine the inhibitory effect of each EO on the radial growth of the fungus, and a dose response was recorded. The EO from O. gratissimum, T. vulgaris and C. citratus were the most effective and prevented conidial germination and the growth of all three fungi on corn meal agar at 800, 1000 and 1200 ppm, respectively. Moderate activity was observed for the EO from Z. officinale between 800 and 2500 ppm, while the EO from M. myristica was less inhibitory. These effects against food spoilage and mycotoxin producing fungi indicated the possible ability of each essential oil as a food preservative. A comparative test on the preservative ability of the EO from O. gratissimum and potassium sorbate against A. flavus at pH 3.0 and 4.5 showed that the EO remained stable at both pH, whereas the efficacy of potassium sorbate was reduced at higher pH. We concluded that the EO from O. gratissimum is a potential food preservative with a pH dependent superiority against potassium sorbate, and these are novel scientific information.

Diversity and Control of Spoilage Fungi in Dairy Products: An Update

Science.gov (United States)

Valence, Florence; Mounier, Jérôme

2017-01-01

Fungi are common contaminants of dairy products, which provide a favorable niche for their growth. They are responsible for visible or non-visible defects, such as off-odor and -flavor, and lead to significant food waste and losses as well as important economic losses. Control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit fungal spoilage in dairy products. Several traditional methods also called traditional hurdle technologies are implemented and combined to prevent and control such contaminations. Prevention methods include good manufacturing and hygiene practices, air filtration, and decontamination systems, while control methods include inactivation treatments, temperature control, and modified atmosphere packaging. However, despite technology advances in existing preservation methods, fungal spoilage is still an issue for dairy manufacturers and in recent years, new (bio) preservation technologies are being developed such as the use of bioprotective cultures. This review summarizes our current knowledge on the diversity of spoilage fungi in dairy products and the traditional and (potentially) new hurdle technologies to control their occurrence in dairy foods. PMID:28788096

Diversity and Control of Spoilage Fungi in Dairy Products: An Update

Directory of Open Access Journals (Sweden)

Lucille Garnier

2017-07-01

Full Text Available Fungi are common contaminants of dairy products, which provide a favorable niche for their growth. They are responsible for visible or non-visible defects, such as off-odor and -flavor, and lead to significant food waste and losses as well as important economic losses. Control of fungal spoilage is a major concern for industrials and scientists that are looking for efficient solutions to prevent and/or limit fungal spoilage in dairy products. Several traditional methods also called traditional hurdle technologies are implemented and combined to prevent and control such contaminations. Prevention methods include good manufacturing and hygiene practices, air filtration, and decontamination systems, while control methods include inactivation treatments, temperature control, and modified atmosphere packaging. However, despite technology advances in existing preservation methods, fungal spoilage is still an issue for dairy manufacturers and in recent years, new (bio preservation technologies are being developed such as the use of bioprotective cultures. This review summarizes our current knowledge on the diversity of spoilage fungi in dairy products and the traditional and (potentially new hurdle technologies to control their occurrence in dairy foods.

Eucalyptus Essential Oil as a Natural Food Preservative: In Vivo and In Vitro Antiyeast Potential

Science.gov (United States)

Bukvicki, Danka; Gottardi, Davide; Malik, Anushree; Guerzoni, Maria Elisabetta

2014-01-01

In this study, the application of eucalyptus essential oil/vapour as beverages preservative is reported. The chemical composition of eucalyptus oil was determined by gas chromatography-mass spectrometry (GC-MS) and solid phase microextraction GC-MS (SPME/GC-MS) analyses. GC-MS revealed that the major constituents were 1,8-cineole (80.5%), limonene (6.5%), α-pinene (5%), and γ-terpinene (2.9%) while SPME/GC-MS showed a relative reduction of 1,8-cineole (63.9%) and an increase of limonene (13.8%), α-pinene (8.87%), and γ-terpinene (3.98%). Antimicrobial potential of essential oil was initially determined in vitro against 8 different food spoilage yeasts by disc diffusion, disc volatilization, and microdilution method. The activity of eucalyptus vapours was significantly higher than the eucalyptus oil. Minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) varied from 0.56 to 4.50 mg/mL and from 1.13 to 9 mg/mL, respectively. Subsequently, the combined efficacy of essential oil and thermal treatment were used to evaluate the preservation of a mixed fruit juice in a time-dependent manner. These results suggest eucalyptus oil as a potent inhibitor of food spoilage yeasts not only in vitro but also in a real food system. Currently, this is the first report that uses eucalyptus essential oil for fruit juice preservation against food spoiling yeast. PMID:25177704

Eucalyptus Essential Oil as a Natural Food Preservative: In Vivo and In Vitro Antiyeast Potential

Directory of Open Access Journals (Sweden)

Amit Kumar Tyagi

2014-01-01

Full Text Available In this study, the application of eucalyptus essential oil/vapour as beverages preservative is reported. The chemical composition of eucalyptus oil was determined by gas chromatography-mass spectrometry (GC-MS and solid phase microextraction GC-MS (SPME/GC-MS analyses. GC-MS revealed that the major constituents were 1,8-cineole (80.5%, limonene (6.5%, α-pinene (5%, and γ-terpinene (2.9% while SPME/GC-MS showed a relative reduction of 1,8-cineole (63.9% and an increase of limonene (13.8%, α-pinene (8.87%, and γ-terpinene (3.98%. Antimicrobial potential of essential oil was initially determined in vitro against 8 different food spoilage yeasts by disc diffusion, disc volatilization, and microdilution method. The activity of eucalyptus vapours was significantly higher than the eucalyptus oil. Minimum inhibitory concentration (MIC and minimum fungicidal concentration (MFC varied from 0.56 to 4.50 mg/mL and from 1.13 to 9 mg/mL, respectively. Subsequently, the combined efficacy of essential oil and thermal treatment were used to evaluate the preservation of a mixed fruit juice in a time-dependent manner. These results suggest eucalyptus oil as a potent inhibitor of food spoilage yeasts not only in vitro but also in a real food system. Currently, this is the first report that uses eucalyptus essential oil for fruit juice preservation against food spoiling yeast.

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

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......Given the need for non-destructive methods and sensors for food spoilage monitoring, we have evaluated sixteen chemo-sensitive compounds incorporated in an array for colorimetric detection of typical spoilage compounds (trimethylamine, dimethylamine, cadaverine, putrescine) and characterized...

Yeast genomics on food flavours

NARCIS (Netherlands)

Schoondermark-Stolk, Sung Ah

2005-01-01

The appearance and concentration of the fusel alcohol 3-methyl-1-butanol is important for the flavour of fermented foods. 3-Methyl-1-butanol is formed by yeast during the conversion of L-leucine. Identification of the enzymes and genes involved in the formation of 3-methyl-1-butanol is a major

Food irradiation

International Nuclear Information System (INIS)

Kobayashi, Yasuhiko; Kikuchi, Masahiro

2009-01-01

Food irradiation can have a number of beneficial effects, including prevention of sprouting; control of insects, parasites, pathogenic and spoilage bacteria, moulds and yeasts; and sterilization, which enables commodities to be stored for long periods. It is most unlikely that all these potential applications will prove commercially acceptable; the extend to which such acceptance is eventually achieved will be determined by practical and economic considerations. A review of the available scientific literature indicates that food irradiation is a thoroughly tested food technology. Safety studies have so far shown no deleterious effects. Irradiation will help to ensure a safer and more plentiful food supply by extending shelf-life and by inactivating pests and pathogens. As long as requirement for good manufacturing practice are implemented, food irradiation is safe and effective. Possible risks of food irradiation are not basically different from those resulting from misuse of other processing methods, such as canning, freezing and pasteurization. (author)

A differential medium for the enumeration of the spoilage yeast Zygosaccharomyces bailii in wine.

Science.gov (United States)

Schuller, D; Côrte-Real, M; Leão, C

2000-11-01

A collection of yeasts, isolated mostly from spoiled wines, was used in order to develop a differential medium for Zygosaccharomyces bailii. The 118 selected strains of 21 species differed in their origin and resistance to preservatives and belonged to the genera Pichia, Torulaspora, Dekkera, Debaryomyces, Saccharomycodes, Issatchenkia, Kluyveromyces, Kloeckera, Lodderomyces, Schizosaccharomyces, Rhodotorula, Saccharomyces, and Zygosaccharomyces. The design of the culture medium was based on the different ability of the various yeast species to grow in a mineral medium with glucose and formic acid (mixed-substrate medium) as the only carbon and energy sources and supplemented with an acid-base indicator. By manipulating the concentration of the acid and the sugar it was possible to select conditions where only Z. bailii strains gave rise to alkalinization, associated with a color change of the medium (positive response). The final composition of the mixed medium was adjusted as a compromise between the percentage of recovery and selectivity for Z. bailii. This was accomplished by the use of pure or mixed cultures of the yeast strains and applying the membrane filtration methodology. The microbiological analysis of two samples of contaminated Vinho Verde showed that the new medium can be considered as a differential medium to distinguish Z. bailii from other contaminating yeasts, having potential application in the microbiological control of wines and probably other beverages and foods.

Meat spoilage during distribution.

Science.gov (United States)

Nychas, George-John E; Skandamis, Panos N; Tassou, Chrysoula C; Koutsoumanis, Konstantinos P

2008-01-01

Meat spoilage during distribution can be considered as an ecological phenomenon that encompasses the changes of the available substrata (e.g., low molecular compounds), during the prevailing of a particular microbial association, the so-called specific spoilage organisms (SSO). In fact, spoilage of meat depends on an even smaller fraction of SSO, called ephemeral spoilage organisms (ESO). These ESO are the consequence of factors that dynamically persist or imposed during, e.g., processing, transportation and storage in the market. Meanwhile spoilage is a subjective judgment by the consumer, which may be influenced by cultural and economic considerations and background as well as by the sensory acuity of the individual and the intensity of the change. Indeed, when spoilage progresses, most consumers would agree that gross discoloration, strong off-odors, and the development of slime would constitute the main qualitative criteria for meat rejection. On the other hand, meat industry needs rapid analytical methods or tools for quantification of these indicators to determine the type of processing needed for their raw material and to predict remaining shelf life of their products. The need of an objective evaluation of meat spoilage is of great importance. The use of metabolomics as a potential tool for the evaluation of meat spoilage can be of great importance. The microbial association of meat should be monitored in parallel with the estimation of changes occurring in the production and/or assimilation of certain compounds would allow us to evaluate spoilage found or produced during the storage of meat under different temperatures as well as packaging conditions.

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.

Optimising the inactivation of grape juice spoilage organisms by pulse electric fields.

Science.gov (United States)

Marsellés-Fontanet, A Robert; Puig, Anna; Olmos, Paola; Mínguez-Sanz, Santiago; Martín-Belloso, Olga

2009-04-15

The effect of some pulsed electric field (PEF) processing parameters (electric field strength, pulse frequency and treatment time), on a mixture of microorganisms (Kloeckera apiculata, Saccharomyces cerevisiae, Lactobacillus plantarum, Lactobacillus hilgardii and Gluconobacter oxydans) typically present in grape juice and wine were evaluated. An experimental design based on response surface methodology (RSM) was used and results were also compared with those of a factorially designed experiment. The relationship between the levels of inactivation of microorganisms and the energy applied to the grape juice was analysed. Yeast and bacteria were inactivated by the PEF treatments, with reductions that ranged from 2.24 to 3.94 log units. All PEF parameters affected microbial inactivation. Optimal inactivation of the mixture of spoilage microorganisms was predicted by the RSM models at 35.0 kV cm(-1) with 303 Hz pulse width for 1 ms. Inactivation was greater for yeasts than for bacteria, as was predicted by the RSM. The maximum efficacy of the PEF treatment for inactivation of microorganisms in grape juice was observed around 1500 MJ L(-1) for all the microorganisms investigated. The RSM could be used in the fruit juice industry to optimise the inactivation of spoilage microorganisms by PEF.

Microbiological Spoilage of Fruits and Vegetables

Science.gov (United States)

Barth, Margaret; Hankinson, Thomas R.; Zhuang, Hong; Breidt, Frederick

Consumption of fruit and vegetable products has dramatically increased in the United States by more than 30% during the past few decades. It is also estimated that about 20% of all fruits and vegetables produced is lost each year due to spoilage. The focus of this chapter is to provide a general background on microbiological spoilage of fruit and vegetable products that are organized in three categories: fresh whole fruits and vegetables, fresh-cut fruits and vegetables, and fermented or acidified vegetable products. This chapter will address characteristics of spoilage microorganisms associated with each of these fruit and vegetable categories including spoilage mechanisms, spoilage defects, prevention and control of spoilage, and methods for detecting spoilage microorganisms.

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.

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)

Hultman, Jenni; Rahkila, Riitta; Ali, Javeria; Rousu, Juho; Björkroth, K Johanna

2015-10-01

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. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Growth inhibition of pathogenic bacteria and some yeasts by selected essential oils and survival of L. monocytogenes and C. albicans in apple-carrot juice.

Science.gov (United States)

Irkin, Reyhan; Korukluoglu, Mihriban

2009-04-01

Food safety is a fundamental concern of both consumers and the food industry. The increasing incidence of foodborne diseases increases the demand of using antimicrobials in foods. Spices and plants are rich in essential oils and show inhibition activity against microorganisms, which are composed of many compounds. In this research, effects of garlic, bay, black pepper, origanum, orange, thyme, tea tree, mint, clove, and cumin essential oils on Listeria monocytogenes AUFE 39237, Escherichia coli ATCC 25922, Salmonella enteritidis ATCC 13076, Proteus mirabilis AUFE 43566, Bacillus cereus AUFE 81154, Saccharomyces uvarum UUFE 16732, Kloeckera apiculata UUFE 10628, Candida albicans ATCC 10231, Candida oleophila UUPP 94365, and Metschnikowia fructicola UUPP 23067 and effects of thyme oil at a concentration of 0.5% on L. monocytogenes and C. albicans in apple-carrot juice during +4 degrees C storage (first to fifth day) were investigated. Strong antibacterial and antifungal activities of some essential oils were found. Thyme, origanum, clove, and orange essential oils were the most inhibitory against bacteria and yeasts. Cumin, tea tree, and mint oils inhibited the yeasts actively. It is concluded that some essential oils could be used as potential biopreservatives capable of controlling foodborne pathogens and food spoilage yeasts.

Brettanomyces bruxellensis yeasts: impact on wine and winemaking.

Science.gov (United States)

Agnolucci, Monica; Tirelli, Antonio; Cocolin, Luca; Toffanin, Annita

2017-09-21

Yeasts belonging to the Brettanomyces/Dekkera genus are non-conventional yeasts, which affect winemaking by causing wine spoilage all over the world. This mini-review focuses on recent results concerning the presence of Brettanomyces bruxellensis throughout the wine processing chain. Here, culture-dependent and independent methods to detect this yeast on grapes and at the very early stage of wine production are encompassed. Chemical, physical and biological tools, devised for the prevention and control of such a detrimental species during winemaking are also presented. Finally, the mini-review identifies future research areas relevant to the improvement of wine safety and sensory profiles.

Probabilistic model for the spoilage wine yeast Dekkera bruxellensis as a function of pH, ethanol and free SO2 using time as a dummy variable.

Science.gov (United States)

Sturm, M E; Arroyo-López, F N; Garrido-Fernández, A; Querol, A; Mercado, L A; Ramirez, M L; Combina, M

2014-01-17

The present study uses a probabilistic model to determine the growth/no growth interfaces of the spoilage wine yeast Dekkera bruxellensis CH29 as a function of ethanol (10-15%, v/v), pH (3.4-4.0) and free SO2 (0-50 mg/l) using time (7, 14, 21 and 30 days) as a dummy variable. The model, built with a total of 756 growth/no growth data obtained in a simile wine medium, could have application in the winery industry to determine the wine conditions needed to inhibit the growth of this species. Thereby, at 12.5% of ethanol and pH 3.7 for a growth probability of 0.01, it is necessary to add 30 mg/l of free SO2 to inhibit yeast growth for 7 days. However, the concentration of free SO2 should be raised to 48 mg/l to achieve a probability of no growth of 0.99 for 30 days under the same wine conditions. Other combinations of environmental variables can also be determined using the mathematical model depending on the needs of the industry. Copyright © 2013 Elsevier B.V. All rights reserved.

Beneficial Effects of Probiotic and Food Borne Yeasts on Human Health

Directory of Open Access Journals (Sweden)

Saloomeh Moslehi-Jenabian

2010-04-01

Full Text Available Besides being important in the fermentation of foods and beverages, yeasts have shown numerous beneficial effects on human health. Among these, probiotic effects are the most well known health effects including prevention and treatment of intestinal diseases and immunomodulatory effects. Other beneficial functions of yeasts are improvement of bioavailability of minerals through the hydrolysis of phytate, folate biofortification and detoxification of mycotoxins due to surface binding to the yeast cell wall.

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...

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.

Inactivation of Spoilage Yeasts by Mentha spicata L. and M. × villosa Huds. Essential Oils in Cashew, Guava, Mango, and Pineapple Juices

Directory of Open Access Journals (Sweden)

Erika T. da Cruz Almeida

2018-05-01

Full Text Available This study evaluated the efficacy of the essential oil from Mentha spicata L. (MSEO and M. × villosa Huds. (MVEO to inactivate Candida albicans, C. tropicalis, Pichia anomala and Saccharomyces cerevisiae in Sabouraud dextrose broth and cashew, guava, mango, and pineapple juices during 72 h of refrigerated storage. The effects of the incorporation of an anti-yeast effective dose of MSEO on some physicochemical and sensory characteristics of juices were evaluated. The incorporation of 3.75 μL/mL MSEO or 15 μL/mL MVEO caused a ≥5-log reductions in counts of C. albicans, P. anomala, and S. cerevisiae in Sabouraud dextrose broth. In cashew and guava juices, 1.875 μL/mL MSEO or 15 μL/mL MVEO caused ≥5-log reductions in counts of P. anomala and S. cerevisiae. In pineapple juice, 3.75 μL/mL MSEO caused ≥5-log reductions in counts of P. anomala and S. cerevisiae; 15 μL/mL MVEO caused ≥5-log reductions in counts of S. cerevisiae in mango juice. The incorporation of 1.875 μL/mL MSEO did not affect the physicochemical parameters of juices and did not induce negative impacts to cause their possible sensory rejection. These results show the potential of MSEO and MVEO, primarily MSEO, to comprise strategies to control spoilage yeasts in fruit juices.

Potential benefits of the application of yeast starters in table olive processing.

Science.gov (United States)

Arroyo-López, Francisco N; Romero-Gil, Verónica; Bautista-Gallego, Joaquín; Rodríguez-Gómez, Francisco; Jiménez-Díaz, Rufino; García-García, Pedro; Querol, Amparo; Garrido-Fernández, Antonio

2012-01-01

Yeasts play an important role in the food and beverage industry, especially in products such as bread, wine, and beer, among many others. However, their use as a starter in table olive processing has not yet been studied in detail. The candidate yeast strains should be able to dominate fermentation, together with lactic acid bacteria, but should also provide a number of beneficial advantages. Technologically, yeasts should resist low pH and high salt concentrations, produce desirable aromas, improve lactic acid bacteria growth, and inhibit spoilage microorganisms. Nowadays, they are being considered as probiotic agents because many species are able to resist the passage through the gastrointestinal tract and show favorable effects on the host. In this way, yeasts may improve the health of consumers by means of the degradation of non-assimilated compounds (such as phytate complexes), a decrease in cholesterol levels, the production of vitamins and antioxidants, the inhibition of pathogens, an adhesion to intestinal cell line Caco-2, and the maintenance of epithelial barrier integrity. Many yeast species, usually found in table olive processing (Wickerhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens, and Kluyveromyces lactis, among others), have exhibited some of these properties. Thus, the selection of the most appropriate strains to be used as starters in this fermented vegetable, alone or in combination with lactic acid bacteria, is a promising research line to develop in the near future.

Potential benefits of the application of yeast starters in table olive processing

Science.gov (United States)

Arroyo-López, Francisco N.; Romero-Gil, Verónica; Bautista-Gallego, Joaquín; Rodríguez-Gómez, Francisco; Jiménez-Díaz, Rufino; García-García, Pedro; Querol, Amparo; Garrido-Fernández, Antonio

2012-01-01

Yeasts play an important role in the food and beverage industry, especially in products such as bread, wine, and beer, among many others. However, their use as a starter in table olive processing has not yet been studied in detail. The candidate yeast strains should be able to dominate fermentation, together with lactic acid bacteria, but should also provide a number of beneficial advantages. Technologically, yeasts should resist low pH and high salt concentrations, produce desirable aromas, improve lactic acid bacteria growth, and inhibit spoilage microorganisms. Nowadays, they are being considered as probiotic agents because many species are able to resist the passage through the gastrointestinal tract and show favorable effects on the host. In this way, yeasts may improve the health of consumers by means of the degradation of non-assimilated compounds (such as phytate complexes), a decrease in cholesterol levels, the production of vitamins and antioxidants, the inhibition of pathogens, an adhesion to intestinal cell line Caco-2, and the maintenance of epithelial barrier integrity. Many yeast species, usually found in table olive processing (Wickerhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens, and Kluyveromyces lactis, among others), have exhibited some of these properties. Thus, the selection of the most appropriate strains to be used as starters in this fermented vegetable, alone or in combination with lactic acid bacteria, is a promising research line to develop in the near future.

Investigations on the Antifungal Effect of Nerol against Aspergillus flavus Causing Food Spoilage

Directory of Open Access Journals (Sweden)

Jun Tian

2013-01-01

Full Text Available The antifungal efficacy of nerol (NEL has been proved against Aspergillus flavus by using in vitro and in vivo tests. The mycelial growth of A. flavus was completely inhibited at concentrations of 0.8 μL/mL and 0.1 μL/mL NEL in the air at contact and vapor conditions, respectively. The NEL also had an evident inhibitory effect on spore germination in A. flavus along with NEL concentration as well as time-dependent kinetic inhibition. The NEL presented noticeable inhibition on dry mycelium weight and synthesis of aflatoxin B1 (AFB1 by A. flavus, totally restraining AFB1 production at 0.6 μL/mL. In real food system, the efficacy of the NEL on resistance to decay development in cherry tomatoes was investigated in vivo by exposing inoculated and control fruit groups to NEL vapor at different concentration. NEL vapors at 0.1 μL/mL air concentration significantly reduced artificially contaminated A. flavus and a broad spectrum of fungal microbiota. Results obtained from presented study showed that the NEL had a great antifungal activity and could be considered as a benefit and safe tool to control food spoilage.

The genome of wine yeast Dekkera bruxellensis provides a tool to explore its food-related properties

Energy Technology Data Exchange (ETDEWEB)

Piskur, Jure; Ling, Zhihao; Marcet-Houben, Marina; Ishchuk, Olena P.; Aerts, Andrea; LaButti, Kurt; Copeland, Alex; Lindquist, Erika; Barry, Kerrie; Compagno, Concetta; Bisson, Linda; Grigoriev, Igor V.; Gabaldon, Toni; Phister, Trevor

2012-03-14

The yeast Dekkera/Brettanomyces bruxellensis can cause enormous economic losses in wine industry due to production of phenolic off-flavor compounds. D. bruxellensis is a distant relative of baker's yeast Saccharomyces cerevisiae. Nevertheless, these two yeasts are often found in the same habitats and share several food-related traits, such as production of high ethanol levels and ability to grow without oxygen. In some food products, like lambic beer, D. bruxellensis can importantly contribute to flavor development. We determined the 13.4 Mb genome sequence of the D. bruxellensis strain Y879 (CBS2499) and deduced the genetic background of several ?food-relevant? properties and evolutionary history of this yeast. Surprisingly, we find that this yeast is phylogenetically distant to other food-related yeasts and most related to Pichia (Komagataella) pastoris, which is an aerobic poor ethanol producer. We further show that the D. bruxellensis genome does not contain an excess of lineage specific duplicated genes nor a horizontally transferred URA1 gene, two crucial events that promoted the evolution of the food relevant traits in the S. cerevisiae lineage. However, D. bruxellensis has several independently duplicated ADH and ADH-like genes, which are likely responsible for metabolism of alcohols, including ethanol, and also a range of aromatic compounds.

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.

In Vitro Antifungal Effect of Black Cumin Seed Quinones against Dairy Spoilage Yeasts at Different Acidity Levels

Czech Academy of Sciences Publication Activity Database

Halamová, K.; Kokoška, L.; Flešar, J.; Skleničková, O.; Svobodová, B.; Maršík, Petr

2010-01-01

Roč. 73, č. 12 (2010), s. 2291-2295 ISSN 0362-028X R&D Projects: GA ČR GA525/08/1179; GA ČR GD525/08/H060 Institutional research plan: CEZ:AV0Z50380511 Keywords : yeast strains * culture conditions * antimicrobial assay Subject RIV: GM - Food Processing Impact factor: 1.720, year: 2010 www.ingentaconnect.com/content/iafp/jfp/2010/00000073/00000012/art00021

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels

Directory of Open Access Journals (Sweden)

W. Hao

2015-06-01

Full Text Available The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR. The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML, 450 g/kg (medium moisture level, MML, and 500 g/kg (high moisture level, HML, and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM basis, yeast populations significantly increased from 107 to 1010 cfu/g during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to 109 cfu/g DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

Aerobic Stability and Effects of Yeasts during Deterioration of Non-fermented and Fermented Total Mixed Ration with Different Moisture Levels.

Science.gov (United States)

Hao, W; Wang, H L; Ning, T T; Yang, F Y; Xu, C C

2015-06-01

The present experiment evaluated the influence of moisture level and anaerobic fermentation on aerobic stability of total mixed ration (TMR). The dynamic changes in chemical composition and microbial population that occur after air exposure were examined, and the species of yeast associated with the deterioration process were also identified in both non-fermented and fermented TMR to deepen the understanding of aerobic deterioration. The moisture levels of TMR in this experiment were adjusted to 400 g/kg (low moisture level, LML), 450 g/kg (medium moisture level, MML), and 500 g/kg (high moisture level, HML), and both non-fermented and 56-d-fermented TMR were subjected to air exposure to determine aerobic stability. Aerobic deterioration resulted in high losses of nutritional components and largely reduced dry matter digestibility. Non-fermented TMR deteriorated during 48 h of air exposure and the HML treatment was more aerobically unstable. On dry matter (DM) basis, yeast populations significantly increased from 10(7) to 10(10) cfu/g during air exposure, and Candida ethanolica was the predominant species during deterioration in non-fermented TMR. Fermented TMR exhibited considerable resistance to aerobic deterioration. Spoilage was only observed in the HML treatment and its yeast population increased dramatically to 10(9) cfu/g DM when air exposure progressed to 30 d. Zygosaccharomyces bailii was the sole yeast species isolated when spoilage occurred. These results confirmed that non-fermented and fermented TMR with a HML are more prone to spoilage, and fermented TMR has considerable resistance to aerobic deterioration. Yeasts can trigger aerobic deterioration in both non-fermented and fermented TMR. C. ethanolica may be involved in the spoilage of non-fermented TMR and the vigorous growth of Z. bailii can initiate aerobic deterioration in fermented TMR.

Phytochemical profiles and antimicrobial activity of aromatic Malaysian herb extracts against food-borne pathogenic and food spoilage microorganisms.

Science.gov (United States)

Aziman, Nurain; Abdullah, Noriham; Noor, Zainon Mohd; Kamarudin, Wan Saidatul Syida Wan; Zulkifli, Khairusy Syakirah

2014-04-01

Preliminary phytochemical and flavonoid compounds of aqueous and ethanolic extracts of 6 aromatic Malaysian herbs were screened and quantified using Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). The herbal extracts were tested for their antimicrobial activity against 10 food-borne pathogenic and food spoilage microorganisms using disk diffusion assay. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)/minimum fungicidal concentration (MFC) of herbal extracts were determined. In the phytochemical screening process, both aqueous and ethanolic extracts of P. hydropiper exhibited presence of all 7 tested phytochemical compounds. Among all herbal extracts, the aqueous P. hydropiper and E. elatior extracts demonstrated the highest antibacterial activity against 7 tested Gram-positive and Gram-negative bacteria with diameter ranging from 7.0 to 18.5 mm and 6.5 to 19 mm, respectively. The MIC values for aqueous and ethanolic extracts ranged from 18.75 to 175 mg/mL and 0.391 to 200 mg/mL, respectively while the MBC/MFC values for aqueous and ethanolic extracts ranged from 25 to 200 mg/mL and 3.125 to 50 mg/mL, respectively. Major types of bioactive compounds in aqueous P. hydropiper and E. elatior extracts were identified using RP-HPLC instrument. Flavonoids found in these plants were epi-catechin, quercetin, and kaempferol. The ability of aqueous Persicaria hydropiper (L.) H. Gross and Etlingera elatior (Jack) R.M. Sm. extracts to inhibit the growth of bacteria is an indication of its broad spectrum antimicrobial potential. Hence these herbal extracts may be used as natural preservative to improve the safety and shelf-life of food and pharmaceutical products. © 2014 Institute of Food Technologists®

A Double-Stimuli-Responsive Fluorescent Center for Monitoring of Food Spoilage based on Dye Covalently Modified EuMOFs: From Sensory Hydrogels to Logic Devices.

Science.gov (United States)

Xu, Xiao-Yu; Lian, Xiao; Hao, Ji-Na; Zhang, Chi; Yan, Bing

2017-10-01

Unsafe food is a huge threat to human health and the economy, and detecting food spoilage early is an ongoing and imperative need. Herein, a simple and effective strategy combining a fluorescence sensor and one-to-two logic operation is designed for monitoring biogenic amines, indicators of food spoilage. Sensors (methyl red@lanthanide metal-organic frameworks (MR@EuMOFs)) are created by covalently modifying MR into NH 2 -rich EuMOFs, which have a high quantum yield (48%). A double-stimuli-responsive fluorescence center is produced via energy transfer from the ligands to Eu 3+ and MR. Portable sensory hydrogels are obtained by dispersing and solidifying MR@EuMOFs in water-phase sodium salt of carboxy methyl cellulose (CMC-Na). The hydrogels exhibit a color transition upon "smelling" histamine (HI) vapor. This transition and shift in the MR-based emission peak are closely related to the HI concentration. Using the HI concentration as the input signal and the two fluorescence emissions as output signals, an advanced analytical device based on a one-to-two logic gate is constructed. The four output combinations, NOT (0, 1), YES (1, 0), PASS 1 (1, 1), and PASS 0 (0, 0), allow the direct analysis of HI levels, which can be used for real-time food-freshness evaluation. The novel strategy suggested here may be a new application for a molecular logic system in the sensing field. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Potential benefits of the application of yeast starters in table olive processing

Directory of Open Access Journals (Sweden)

Francisco Noé eArroyo López

2012-04-01

Full Text Available Yeasts play an important role in the food and beverage industry, especially in products such as bread, wine, and beer, among many others. However, their use as a starter in table olive processing has not yet been studied in detail. The candidate yeast strains should be able to dominate fermentation, together with lactic acid bacteria, but should also provide a number of beneficial advantages. Technologically, yeasts should resist low pH and high salt concentrations, produce desirable aromas, improve lactic acid bacteria growth and inhibit spoilage microorganisms. Nowadays, they are being considered as probiotic agents because many species are able to resist the passage through the gastrointestinal tract and show favourable effects on the host. In this way, yeasts may improve the health of consumers by means of the degradation of non assimilated compounds (such as phytate complexes, a decrease in cholesterol levels, the production of vitamins and antioxidants, the inhibition of pathogens, an adhesion to intestinal cell line Caco-2 and the maintenance of epithelial barrier integrity. Many yeast species, usually found in table olive processing (Wicherhamomyces anomalus, Saccharomyces cerevisiae, Pichia membranifaciens, Kluyveromyces lactis, among others, have exhibited some of these properties. Thus, the selection of the most appropriate strains to be used as starters in this fermented vegetable, alone or in combination with lactic acid bacteria, is a promising research line to develop in the near future.

Screening of intact yeasts and cell extracts to reduce Scrapie prions during biotransformation of food waste.

Science.gov (United States)

Huyben, David; Boqvist, Sofia; Passoth, Volkmar; Renström, Lena; Allard Bengtsson, Ulrika; Andréoletti, Olivier; Kiessling, Anders; Lundh, Torbjörn; Vågsholm, Ivar

2018-02-08

Yeasts can be used to convert organic food wastes to protein-rich animal feed in order to recapture nutrients. However, the reuse of animal-derived waste poses a risk for the transmission of infectious prions that can cause neurodegeneration and fatality in humans and animals. The aim of this study was to investigate the ability of yeasts to reduce prion activity during the biotransformation of waste substrates-thereby becoming a biosafety hurdle in such a circular food system. During pre-screening, 30 yeast isolates were spiked with Classical Scrapie prions and incubated for 72 h in casein substrate, as a waste substitute. Based on reduced Scrapie seeding activity, waste biotransformation and protease activities, intact cells and cell extracts of 10 yeasts were further tested. Prion analysis showed that five yeast species reduced Scrapie seeding activity by approximately 1 log10 or 90%. Cryptococcus laurentii showed the most potential to reduce prion activity since both intact and extracted cells reduced Scrapie by 1 log10 and achieved the highest protease activity. These results show that select forms of yeast can act as a prion hurdle during the biotransformation of waste. However, the limited ability of yeasts to reduce prion activity warrants caution as a sole barrier to transmission as higher log reductions are needed before using waste-cultured yeast in circular food systems.

Use of non-saccharomyces Torulaspora delbrueckii yeast strains in winemaking and brewing

Directory of Open Access Journals (Sweden)

Tataridis Panagiotis

2013-01-01

Full Text Available Selected Saccharomyces yeast strains have been used for more than 150 years in brewing and for several decades in winemaking. They are necessary in brewing because of the boiling of the wort, which results in the death of all yeast cells, with the exception of some Belgian style beers (ex. Lambic, where the wort is left to be colonized by indigenous yeast and bacteria from the environment and ferment naturally. In winemaking their use is also pertinent because they provide regular and timely fermentations, inhibit the growth of indigenous spoilage microorganisms and contribute to the desired sensory characters. Even though the use of selected Saccharomyces strains provides better quality assurance in winemaking in comparison to the unknown microbial consortia in the must, it has been debated for a long time now whether the use of selected industrial Saccharomyces strains results in wines with less sensory complexity and “terroir” character. In previous decades, non-Saccharomyces yeasts were mainly considered as spoilage/problematic yeast, since they exhibited low fermentation ability and other negative traits. In the last decades experiments have shown that there are some non-Saccharomyces strains (Candida, Pichia, Kluyveromyces, Torulaspora, etc which, even though they are not able to complete the fermentation they can still be used in sequential inoculation-fermentation with Saccharomyces to increase sensory complexity of the wines. Through fermentation in a laboratory scale, we have observed that the overall effects of selected Torulaspora delbrueckii yeast strains, is highly positive, leading to products with pronounced sensory complexity and floral/fruity aroma in winemaking and brewing.

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.

High-throughput screening of a large collection of non-conventional yeasts reveals their potential for aroma formation in food fermentation

NARCIS (Netherlands)

Gamero, Amparo; Quintilla, R.; Groenewald, Marizeth; Alkema, Wynand; Boekhout, Teun; Hazelwood, Lucie

2016-01-01

Saccharomyces yeast species are currently the most important yeasts involved in industrial-scale food fermentations. However, there are hundreds of other yeast species poorly studied that are highly promising for flavour development, some of which have also been identified in traditional food

Urea production by yeasts other than Saccharomyces in food fermentation

NARCIS (Netherlands)

Wu, Qun; Cui, Kaixiang; Lin, Jianchun; Zhu, Yang; Xu, Yan

2017-01-01

Urea is an important intermediate in the synthesis of carcinogenic ethyl carbamate in various food fermentations. Identifying urea-producing microorganisms can help control or reduce ethyl carbamate production. Using Chinese liquor fermentation as a model system, we identified the yeasts responsible

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 is notable that many are dependent on the production of volatile signals or signals which have volatile derivatives. Ethylene (ET) has long been recognized as an important regulator of development, stress responses, senescence and food spoilage. Our work has focused on the gaseous signal nitric oxide (NO......) and how it interacts with established stress signalling pathways and in particular, those regulated by ET. Using laser photoacoustic detection (LPAD) we have established that NO production overlaps with that of ethylene during plant responses to disease. To examine the interaction of NO and ET signalling...

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

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

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.

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 ...

Comparison of culture media, simplate, and petrifilm for enumeration of yeasts and molds in food.

Science.gov (United States)

Taniwaki, M H; Silva, N; Banhe, A A; Iamanaka, B T

2001-10-01

The efficacy of three culture media, dichloran rose bengal chloramphenicol (DRBC), dichloran 18% glycerol agar (DG18), and potato dextrose agar (PDA) supplemented with two antibiotics, were compared with the Simplate and Petrifilm techniques for mold and yeast enumeration. The following foods were analyzed: corn meal, wheat flour, cassava flour, bread crumbs, whole meal, sliced bread, ground peanuts, mozzarella cheese, grated parmesan cheese, cheese rolls, orange juice, pineapple pulp, pineapple cake, and mushroom in conserve. Correlation coefficients of DRBC versus PDA and DG18 for recovering total mold and yeast counts from the composite of 14 foods indicated that the three media were generally equivalent. Correlation coefficients for Petrifilm versus culture media were acceptable, although not as good as between culture media. Correlation coefficients of Simplate versus DRBC, DG18, PDA, and Petrifilm for recovering total yeasts and molds from a composite of 11 foods demonstrated that there was no equivalence between the counts obtained by Simplate and other culture media and Petrifilm, with significant differences observed for the most foods analyzed.

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

OpenAIRE

Monir Doudi; Mahbubeh Setorki; Zahra Rezayatmand

2016-01-01

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 sele...

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 ...

Beneficial effects of probiotic and food borne yeasts on human health

DEFF Research Database (Denmark)

Moslehi Jenabian, Saloomeh; Pedersen, Line Lindegaard; Jespersen, Lene

2010-01-01

Besides being important in the fermentation of foods and beverages, yeasts have shown numerous beneficial effects on human health. Among these, propiotic effects are the most well known health effects including prevention and treatment of intestinal diseases and immunomodulatory effects. Other...

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.

FUNCTIONAL PROPERTIES OF YEASTS ISOLATED FROM SOME NIGERIAN TRADITIONAL FERMENTED FOODS

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Tolulope P. Alakeji

2015-04-01

Full Text Available Yeasts play important roles in confering some desirable qualities such as nutritional value in traditional fermented foods. This study was carried out to investigate the potentials of yeasts isolated from some Nigerian traditional fermented foods for functional characteristics such as growth at pH 2.5 and 2% bile salts concentration and ability to lower cholesterol in culture medium. A total of 40 yeast strains were isolated from burukutu, ogi and pito. They were characterized phenotypically. Fifteen strains were selected based on the ability to tolerate pH 2.5 and 2% bile salts and they were further identified using API 20C AUX (Biomerieux, France to be Debaryomyces hansenii (5, Candida krusei (4, Candida glabrata (2, Candida colliculosa (1, Pichia anomala (1, Pichia farinosa (1 and Pichia membranefaciens (1. At pH 2.5, C. glabrata SA2 showed the highest increase in viable cells count after 24h (6.31 log10 cfu ml-1 while the most sensitive strain was P. membranefaciens BA2 (0.70 log10 cfu ml-1. P. membranefaciens BA2 survived in 2% bile salts than other yeast strains, with viable cell increase of 0.84 log10 cfu ml-1 after 24 h while the least tolerance was observed for D. hansenii OA1 with an increase in viable cells of 7.76 log10 cfu ml-1. C. krusei OB1 exhibited the greatest reduction of cholesterol of 91.34% while the least reduction of 24.28% was observed for D. hansenii OA1 after 48h incubation. The yeast strains in this study demonstrated functional attributes which can be employed as dietary adjuncts for the development of non-dairy beverages with hypocholesterolemic attributes.

Principles and application of high pressure-based technologies in the food industry.

Science.gov (United States)

Balasubramaniam, V M Bala; Martínez-Monteagudo, Sergio I; Gupta, Rockendra

2015-01-01

High pressure processing (HPP) has emerged as a commercially viable food manufacturing tool that satisfies consumers' demand for mildly processed, convenient, fresh-tasting foods with minimal to no preservatives. Pressure treatment, with or without heat, inactivates pathogenic and spoilage bacteria, yeast, mold, viruses, and also spores and extends shelf life. Pressure treatment at ambient or chilled temperatures has minimal impact on product chemistry. The product quality and shelf life are often influenced more by storage conditions and packaging material barrier properties than the treatment itself. Application of pressure reduces the thermal exposure of the food during processing, thereby protecting a variety of bioactive compounds. This review discusses recent scientific advances of high pressure technology for food processing and preservation applications such as pasteurization, sterilization, blanching, freezing, and thawing. We highlight the importance of in situ engineering and thermodynamic properties of food and packaging materials in process design. Current and potential future promising applications of pressure technology are summarized.

Radiation microbiology relevant to the food industry

International Nuclear Information System (INIS)

Holzapfel, W.H.

1985-01-01

Destruction or inactivation of most microbial cells takes place at relatively low doses of gamma irradiation, making 'pasteurising' treatment of several food commodities in the dose range of 1 to 10 kGy a feasible decontamination method. Several factors may influence the effectiveness of an irradiation process, and should be taken into account when radurisation of foods is practised. Damage to microbes is enhanced in the presence of oxygen and at low pH levels, whereas substances such as sulfhydryl compounds tend to act as protectors. Living organisms may be arranged in the order of increasing resistance to ionising radiation, as follows: higher animals, insects, vegetative bacteria, yeasts and fungi, bacterial endospores and viruses. Most food spoilage organisms as well as food-borne pathogens (D 10 -values for the majority ranging between 0,08 and 0,5 kGy) are sensitive to relatively small irradiation doses. Although several bacterial endospores may survive in radurised foods (D 10 -values ranging between 1,5 and 5,0 kGy), additional safety factors (e.g. low pH, refrigeration, reduced Eh, reduced a w , preservatives) may contribute to the shelf stability of a given food

Genome and transcriptome analysis of the food-yeast Candida utilis.

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Yasuyuki Tomita

Full Text Available The industrially important food-yeast Candida utilis is a Crabtree effect-negative yeast used to produce valuable chemicals and recombinant proteins. In the present study, we conducted whole genome sequencing and phylogenetic analysis of C. utilis, which showed that this yeast diverged long before the formation of the CUG and Saccharomyces/Kluyveromyces clades. In addition, we performed comparative genome and transcriptome analyses using next-generation sequencing, which resulted in the identification of genes important for characteristic phenotypes of C. utilis such as those involved in nitrate assimilation, in addition to the gene encoding the functional hexose transporter. We also found that an antisense transcript of the alcohol dehydrogenase gene, which in silico analysis did not predict to be a functional gene, was transcribed in the stationary-phase, suggesting a novel system of repression of ethanol production. These findings should facilitate the development of more sophisticated systems for the production of useful reagents using C. utilis.

Effect of High Intensity Ultrasound Treatment on the Growth of Food Spoilage Bacteria

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Ksenija Markov

2013-01-01

Full Text Available The aim of this study is to determine the effect of high intensity ultrasound (amplitude, temperature and treatment time on the inactivation of food spoilage bacteria Escherichia coli 3014, Staphylococcus aureus 3048, Salmonella sp. 3064, Listeria monocytogenes ATCC 23074 and Bacillus cereus 30. The model suspensions of bacteria were treated with 12.7-mm ultrasonic probe operated at 600 W nominal power (ultrasonic treatment implemented at 20 kHz and at amplitudes of 60, 90 and 120 µm. Also, treatment time of 3, 6 and 9 min and temperature of 20, 40 and 60 °C were used. The results were statistically processed with STATGRAPHICS Centurion computer program and response surface methodology. All three parameters studied seem to substantially affect the inactivation of bacteria in pure culture. The results also indicate increased inactivation of microorganisms under longer period of treatments, particularly in combination with higher temperature and/or amplitude. After ultrasonic treatment at 60 °C, 9 min and 120 μm, the viability of cells was not confirmed for Escherichia coli 3014, Staphylococcus aureus 3048, Salmonella sp. 3064 and Listeria monocytogenes ATCC 23074. Under the mentioned conditions the highest inactivation (3.48 log CFU/mL of Bacillus cereus 30 was obtained.

Presence and changes in populations of yeasts on raw and processed poultry products stored at refrigeration temperature.

Science.gov (United States)

Ismail, S A; Deak, T; El-Rahman, H A; Yassien, M A; Beuchat, L R

2000-12-05

A study was undertaken to determine populations and profiles of yeast species on fresh and processed poultry products upon purchase from retail supermarkets and after storage at 5 degrees C until shelf life expiration, and to assess the potential role of these yeasts in product spoilage. Fifty samples representing 15 commercial raw, marinated, smoked, or roasted chicken and turkey products were analyzed. Yeast populations were determined by plating on dichloran rose bengal chloramphenicol (DRBC) agar and tryptone glucose yeast extract (TGY) agar. Proteolytic activity was determined using caseinate and gelatin agars and lipolytic activity was determined on plate count agar supplemented with tributyrin. Populations of aerobic microorganisms were also determined. Initial populations of yeasts (log10 cfu/g) ranged from less than 1 (detection limit) to 2.89, and increased by the expiration date to 0.37-5.06, indicating the presence of psychrotrophic species. Highest initial populations were detected in raw chicken breast, wings, and ground chicken, as well as in turkey necks and legs, whereas roasted chicken and turkey products contained less than 1 log10 cfu/g. During storage, yeast populations increased significantly (P chicken, ground chicken, liver, heart and gizzard, and in ground turkey and turkey sausage. Isolates (152 strains) of yeasts from poultry products consisted of 12 species. Yarrowia lipolytica and Candida zeylanoides were predominant, making up 39 and 26% of the isolates, respectively. Six different species of basidiomycetous yeasts representing 24% of the isolates were identified. Most Y. lipolytica strains showed strong proteolytic and lipolytic activities, whereas C. zeylanoides was weakly lipolytic. Results suggest that yeasts, particularly Y. lipolytica, may play a more prominent role than previously recognized in the spoilage of fresh and processed poultry stored at 5 degrees C.

Spoilage potential of brettanomyces bruxellensis strains isolated from Italian wines.

Science.gov (United States)

Guzzon, Raffaele; Larcher, Roberto; Guarcello, Rosa; Francesca, Nicola; Settanni, Luca; Moschetti, Giancarlo

2018-03-01

Brettanomyces bruxellensis is an important wine spoilage agent. In this study a population of Brettanomyces strains isolated from Italian wines was thoroughly investigated to evaluate adaptability to wine conditions and spoilage potential. The presumptive isolates of Brettanomyces were identified at species level with 26S rRNA gene sequencing and species-specific PCR, and subsequently subjected to analysis of intra-species variability through the study of intron splice sites (ISS-PCR). Although, some strains were tracked in wines from different regions, extensive genetic biodiversity was observed within the B. bruxellensis population investigated. All strains were evaluated for their growth ability in the presence of ethanol, high sugar content, low pH, different temperatures and sulphur dioxide, using optical density and flow cytometry measurement. The ability of yeasts to produce ethyl phenols in red wines with different chemical compositions was evaluated by means of high performance liquid chromatography with electrochemical detection (HPLC-ECD). The results highlighted wide variability in B. bruxellensis in response to wine limiting factors and in terms of the accumulation of ethyl phenols. As regards this last aspect, the differences found among strains were closely related to chemical composition of wine and strain resistance to environmental stress factors, making a priori evaluation of risk of wine alteration quite difficult. These results suggest that strategies for the control of Brettanomyces should be tailored on the basis of strain distribution and wine characteristics. Copyright © 2017. Published by Elsevier Ltd.

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

Science.gov (United States)

Aneja, Kamal Rai; Dhiman, Romika; Aggarwal, Neeraj Kumar; Aneja, Ashish

2014-01-01

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. PMID:25332721

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.

Emerging preservation techniques for controlling spoilage and pathogenic microorganisms in fruit juices.

Science.gov (United States)

Aneja, Kamal Rai; Dhiman, Romika; Aggarwal, Neeraj Kumar; Aneja, Ashish

2014-01-01

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.

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.

Not your ordinary yeast: non-Saccharomyces yeasts in wine production uncovered.

Science.gov (United States)

Jolly, Neil P; Varela, Cristian; Pretorius, Isak S

2014-03-01

Saccharomyces cerevisiae and grape juice are 'natural companions' and make a happy wine marriage. However, this relationship can be enriched by allowing 'wild' non-Saccharomyces yeast to participate in a sequential manner in the early phases of grape must fermentation. However, such a triangular relationship is complex and can only be taken to 'the next level' if there are no spoilage yeast present and if the 'wine yeast' - S. cerevisiae - is able to exert its dominance in time to successfully complete the alcoholic fermentation. Winemakers apply various 'matchmaking' strategies (e.g. cellar hygiene, pH, SO2 , temperature and nutrient management) to keep 'spoilers' (e.g. Dekkera bruxellensis) at bay, and allow 'compatible' wild yeast (e.g. Torulaspora delbrueckii, Pichia kluyveri, Lachancea thermotolerans and Candida/Metschnikowia pulcherrima) to harmonize with potent S. cerevisiae wine yeast and bring the best out in wine. Mismatching can lead to a 'two is company, three is a crowd' scenario. More than 40 of the 1500 known yeast species have been isolated from grape must. In this article, we review the specific flavour-active characteristics of those non-Saccharomyces species that might play a positive role in both spontaneous and inoculated wine ferments. We seek to present 'single-species' and 'multi-species' ferments in a new light and a new context, and we raise important questions about the direction of mixed-fermentation research to address market trends regarding so-called 'natural' wines. This review also highlights that, despite the fact that most frontier research and technological developments are often focussed primarily on S. cerevisiae, non-Saccharomyces research can benefit from the techniques and knowledge developed by research on the former. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Rapid and quantitative detection of the microbial spoilage of meat by fourier transform infrared spectroscopy and machine learning.

Science.gov (United States)

Ellis, David I; Broadhurst, David; Kell, Douglas B; Rowland, Jem J; Goodacre, Royston

2002-06-01

Fourier transform infrared (FT-IR) spectroscopy is a rapid, noninvasive technique with considerable potential for application in the food and related industries. We show here that this technique can be used directly on the surface of food to produce biochemically interpretable "fingerprints." Spoilage in meat is the result of decomposition and the formation of metabolites caused by the growth and enzymatic activity of microorganisms. FT-IR was exploited to measure biochemical changes within the meat substrate, enhancing and accelerating the detection of microbial spoilage. Chicken breasts were purchased from a national retailer, comminuted for 10 s, and left to spoil at room temperature for 24 h. Every hour, FT-IR measurements were taken directly from the meat surface using attenuated total reflectance, and the total viable counts were obtained by classical plating methods. Quantitative interpretation of FT-IR spectra was possible using partial least-squares regression and allowed accurate estimates of bacterial loads to be calculated directly from the meat surface in 60 s. Genetic programming was used to derive rules showing that at levels of 10(7) bacteria.g(-1) the main biochemical indicator of spoilage was the onset of proteolysis. Thus, using FT-IR we were able to acquire a metabolic snapshot and quantify, noninvasively, the microbial loads of food samples accurately and rapidly in 60 s, directly from the sample surface. We believe this approach will aid in the Hazard Analysis Critical Control Point process for the assessment of the microbiological safety of food at the production, processing, manufacturing, packaging, and storage levels.

Identification of food spoilage in the smart home based on neural and fuzzy processing of odour sensor responses.

Science.gov (United States)

Green, Geoffrey C; Chan, Adrian D C; Goubran, Rafik A

2009-01-01

Adopting the use of real-time odour monitoring in the smart home has the potential to alert the occupant of unsafe or unsanitary conditions. In this paper, we measured (with a commercial metal-oxide sensor-based electronic nose) the odours of five household foods that had been left out at room temperature for a week to spoil. A multilayer perceptron (MLP) neural network was trained to recognize the age of the samples (a quantity related to the degree of spoilage). For four of these foods, median correlation coefficients (between target values and MLP outputs) of R > 0.97 were observed. Fuzzy C-means clustering (FCM) was applied to the evolving odour patterns of spoiling milk, which had been sampled more frequently (4h intervals for 7 days). The FCM results showed that both the freshest and oldest milk samples had a high degree of membership in "fresh" and "spoiled" clusters, respectively. In the future, as advancements in electronic nose development remove the present barriers to acceptance, signal processing methods like those explored in this paper can be incorporated into odour monitoring systems used in the smart home.

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.

21 CFR 172.898 - Bakers yeast glycan.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Bakers yeast glycan. 172.898 Section 172.898 Food... Multipurpose Additives § 172.898 Bakers yeast glycan. Bakers yeast glycan may be safely used in food in accordance with the following conditions: (a) Bakers yeast glycan is the comminuted, washed, pasteurized, and...

The use of ionizing radiation to reduce food spoilage by microorganisms

International Nuclear Information System (INIS)

Mosquera, Monica; Gomezjurado, Silvia; Munoz, Ricardo

1990-01-01

The contamination of Aspergillus flavus is studied in yellow maize, Zea mays, Peanuts, Arachis hipoguea, L.; Casabe, Yuca. Manhot esculenta, D.C. The contents of aflotoxines B 1 , B 2 , G 1 and G 2 is analized in food stuffs of popular consumption. The samples with higher contamination of A. flavus were irradiated with 1-3 KGy, and combined processes with gamma irradiation were assayed with previous and separate treatments with ammonia and hipochlorite. Thus, it was possible to lower the contamination of this fungus from 10 3 u.f.c/g to 10. Separate edible mushrooms of species Boletus edulis, were radurized with gamma irradiation dose of 2 KGy. It was possible to reduce the contamination of 10 7 microorganism/gram, to the value 10 3 - 10 2 microorganism/gram. The microbial contamination of 18 species and aromatic herbs is also studied. The contaminating fungi of these food products as well as of the edible mushrooms, were identified as Penicillum, Geortrichum, Mucor, Galdosporium and yeasts of Canida sp. The optimal irradiation doses of same species and tea herbs, are determined. At the same time de d10 irradiation doses for pure stubs of main microorganisms are determined. To reduce the microbial contamination of many foodstuffs to maximun permisible values it is proposed thesi technology eitherwith only irradiation, or with combined treatments with irradiation

Estrogenic Activities of Food Supplements and Beers as Assessed by a Yeast Bioreporter Assay.

Science.gov (United States)

Omoruyi, Iyekhoetin Matthew; Pohjanvirta, Raimo

2017-10-31

Mounting evidence of the effects of endocrine-disrupting chemicals (EDCs) in humans has led to assaying a vast array of food items (processed or packaged) as possible sources of human exposure to estrogens. In this study, we investigated the current situation in this respect of different food supplements and beer brands. Eleven food supplements and 24 beer brands were obtained from Helsinki, Finland. Sample preparation was carried out by established methods while estrogenic activities were assessed by a yeast bioluminescent assay, using two recombinant yeast strains (Saccharomyces cerevisiae BMAEREluc/ERα and S. cerevisiae BMA64/luc). All the food supplements as well as 81% of the beer samples tested were found to be estrogenic, with estradiol equivalent concentrations of food supplements and beer brands ranging from 7.5 to 11.5 µg/ml and from below detection limits to 43.6 ng/ml, respectively. The estrogenic activities detected in beer samples were not dependent on the beer's alcoholic content, the country of production, or the size of the production brewery. The results of our study imply that both food supplements and beers can be a significant source of human exposure to estrogens. Therefore, further studies and regular surveillance are warranted.

A mechanistic approach to postirradiation spoilage kinetics of fish

International Nuclear Information System (INIS)

Tukenmez, I.

2004-01-01

Full text: In order to simulate postirradiation spoilage of fish, the mechanistic aspects of the growth of surviving microorganisms during chill storage and their product formation in irradiated fish were analyzed. Anchovy (Engraulis encrasicholus) samples those unirradiated and irradiated at 1, 2 and 3 kGy doses of gamma radiation were stored at +2 o C for 21 days. Total bacterial counts (TBC) and trimethylamine (TMA) analysis of the samples were done periodically during storage. Depending on the proposed spoilage mechanism, kinetic model equations were derived. By using experimental data of TBC and TMA in the developed model, the postirradiation spoilage parameters including growth rate constant, inital and maximum attainable TBC, lag time and TMA yield were evaluated and microbial spoilage of fish was simulated for postirradiation storage. Shelf life of irradiated fish was estimated depending on the spoilage kinetics. Dose effects on the kinetic parameters were analyzed. It is suggested that the kinetic evaluation method developed in this study may be used for quality assessment, shelf life determination and dose optimization for radiation preservation of fish

Decontamination of food packaging using electron beam--status and prospects

Energy Technology Data Exchange (ETDEWEB)

Mittendorfer, J. E-mail: htcmitt@eunet.at; Bierbaumer, H.P.; Gratzl, F.; Kellauer, E

2002-03-01

In this paper the status of food packaging disinfection decontamination using electron beam at Mediscan GmbH is presented. The first section of the paper describes the activities at the service center, where food packaging materials, e.g. yoghurt cups are decontaminated in their final shipment containers. As important step in the hazard analysis and critical control point of food processing, microbiological uncontaminated food packaging material is of public interest and attracts a lot of attention from packaging material producers and food processors. The dose ranges for different sterility assurance levels are discussed and results from microbiological test are presented. Studies at Mediscan have demonstrated, that an electron beam treatment at a dose of 5-7 kGy is most effective against yeast and mold, which are mainly responsible for spoilage and short shelf-life of a variety of products. The second section is devoted to the field of inline decontamination of food packaging and sterilization of pharmaceutical packaging material and the research currently conducted at Mediscan. The requirements for industrial inline electron beam systems are summarized and design concepts discussed in terms of beam energy, beam current, irradiation topology, product handling and shielding.

Decontamination of food packaging using electron beam—status and prospects

Science.gov (United States)

Mittendorfer, J.; Bierbaumer, H. P.; Gratzl, F.; Kellauer, E.

2002-03-01

In this paper the status of food packaging disinfection decontamination using electron beam at Mediscan GmbH is presented. The first section of the paper describes the activities at the service center, where food packaging materials, e.g. yoghurt cups are decontaminated in their final shipment containers. As important step in the hazard analysis and critical control point of food processing, microbiological uncontaminated food packaging material is of public interest and attracts a lot of attention from packaging material producers and food processors. The dose ranges for different sterility assurance levels are discussed and results from microbiological test are presented. Studies at Mediscan have demonstrated, that an electron beam treatment at a dose of 5-7 kGy is most effective against yeast and mold, which are mainly responsible for spoilage and short shelf-life of a variety of products. The second section is devoted to the field of inline decontamination of food packaging and sterilization of pharmaceutical packaging material and the research currently conducted at Mediscan. The requirements for industrial inline electron beam systems are summarized and design concepts discussed in terms of beam energy, beam current, irradiation topology, product handling and shielding.

Decontamination of food packaging using electron beam--status and prospects

International Nuclear Information System (INIS)

Mittendorfer, J.; Bierbaumer, H.P.; Gratzl, F.; Kellauer, E.

2002-01-01

In this paper the status of food packaging disinfection decontamination using electron beam at Mediscan GmbH is presented. The first section of the paper describes the activities at the service center, where food packaging materials, e.g. yoghurt cups are decontaminated in their final shipment containers. As important step in the hazard analysis and critical control point of food processing, microbiological uncontaminated food packaging material is of public interest and attracts a lot of attention from packaging material producers and food processors. The dose ranges for different sterility assurance levels are discussed and results from microbiological test are presented. Studies at Mediscan have demonstrated, that an electron beam treatment at a dose of 5-7 kGy is most effective against yeast and mold, which are mainly responsible for spoilage and short shelf-life of a variety of products. The second section is devoted to the field of inline decontamination of food packaging and sterilization of pharmaceutical packaging material and the research currently conducted at Mediscan. The requirements for industrial inline electron beam systems are summarized and design concepts discussed in terms of beam energy, beam current, irradiation topology, product handling and shielding

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.

Microbial control and food Preservation: Theory and practice:Principles of food preservation

Science.gov (United States)

Food preservation is an action or method used to maintain foods at certain desirable properties or quality to obtain maximum benefit. A good method of food preservation is one that slows down or prevents altogether the action of the agents of spoilage without damaging the food. To achieve this, cert...

Yeast identification: reassessment of assimilation tests as sole universal identifiers.

Science.gov (United States)

Spencer, J; Rawling, S; Stratford, M; Steels, H; Novodvorska, M; Archer, D B; Chandra, S

2011-11-01

To assess whether assimilation tests in isolation remain a valid method of identification of yeasts, when applied to a wide range of environmental and spoilage isolates. Seventy-one yeast strains were isolated from a soft drinks factory. These were identified using assimilation tests and by D1/D2 rDNA sequencing. When compared to sequencing, assimilation test identifications (MicroLog™) were 18·3% correct, a further 14·1% correct within the genus and 67·6% were incorrectly identified. The majority of the latter could be attributed to the rise in newly reported yeast species. Assimilation tests alone are unreliable as a universal means of yeast identification, because of numerous new species, variability of strains and increasing coincidence of assimilation profiles. Assimilation tests still have a useful role in the identification of common species, such as the majority of clinical isolates. It is probable, based on these results, that many yeast identifications reported in older literature are incorrect. This emphasizes the crucial need for accurate identification in present and future publications. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

Antibacterial activity of Rosmarinus officinalis L. and Thymus vulgaris L. essential oils and their combination against food-borne pathogens and spoilage bacteria in ready-to-eat vegetables.

Science.gov (United States)

Iseppi, Ramona; Sabia, Carla; de Niederhäusern, Simona; Pellati, Federica; Benvenuti, Stefania; Tardugno, Roberta; Bondi, Moreno; Messi, Patrizia

2018-06-06

The antibacterial activity of Rosmarinus officinalis L. and Thymus vulgaris L. essential oils (EOs), and their combination against food-borne and spoilage bacteria (Listeria monocytogenes, Salmonella enteritidis, Yersinia enterocolitica, Escherichia coli and Pseudomonas spp.) was determined. The EOs inhibitory effect was evaluated both in vitro by using the disk diffusion assay and the minimum inhibitory concentration (MIC) determination, and on food by using an artificially contaminated ready-to-eat (RTE) vegetables. The results showed that the lowest MIC values were obtained with R. officinalis and T. vulgaris EOs against E. coli (4 and 8 μL/mL, respectively). The incorporation of the EOs alone or their combination in RTE vegetables reduced the viable counts of all the tested strains. Lastly, in the on food study we simulated the worst hygienic conditions, obtaining results that can be considered a warranty of safety.

Food-Associated Lactobacillus plantarum and Yeasts Inhibit the Genotoxic Effect of 4-Nitroquinoline-1-Oxide

Directory of Open Access Journals (Sweden)

Roberta Prete

2017-11-01

Full Text Available Lactic acid bacteria and yeasts, representing the prevailing microbiota associated with different foods generally consumed without any cooking, were identified and characterized in vitro for some functional properties, such as acid-bile tolerance and antigenotoxic activity. In particular, 22 Lactobacillus plantarum strains and 14 yeasts were studied. The gastro-intestinal tract tolerance of all the strains was determined by exposing washed cell suspensions at 37°C to a simulated gastric juice (pH 2.0, containing pepsin (0.3% w/v and to a simulated small intestinal juice (pH 8.0, containing pancreatin (1 mg mL-1 and bile extract (0.5%, thus monitoring changes in total viable count. In general, following a strain-dependent behavior, all the tested strains persisted alive after combined acid-bile challenge. Moreover, many strains showed high in vitro inhibitory activity against a model genotoxin, 4-nitroquinoline-1-oxide (4-NQO, as determined by the short-term method, SOS-Chromotest. Interestingly, the supernatants from bacteria- or yeasts-genotoxin co-incubations exhibited a suppression on SOS-induction produced by 4-NQO on the tester strain Escherichia coli PQ37 (sfiA::lacZ exceeding, in general, the value of 75%. The results highlight that food associated microorganisms may reach the gut in viable form and prevent genotoxin DNA damage in situ. Our experiments can contribute to elucidate the functional role of food-associated microorganisms general recognized as safe ingested with foods as a part of the diet.

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.

Biotechnological exploitation of Tetrapisispora phaffii killer toxin: heterologous production in Komagataella phaffii (Pichia pastoris).

Science.gov (United States)

Chessa, Rossella; Landolfo, Sara; Ciani, Maurizio; Budroni, Marilena; Zara, Severino; Ustun, Murat; Cakar, Zeynep Petek; Mannazzu, Ilaria

2017-04-01

The use of natural antimicrobials from plants, animals and microorganisms to inhibit the growth of pathogenic and spoilage microorganisms is becoming more frequent. This parallels the increased consumer interest towards consumption of minimally processed food and 'greener' food and beverage additives. Among the natural antimicrobials of microbial origin, the killer toxin produced by the yeast Tetrapisispora phaffii, known as Kpkt, appears to be a promising natural antimicrobial agent. Kpkt is a glycoprotein with β-1,3-glucanase and killer activity, which induces ultrastructural modifications to the cell wall of yeast of the genera Kloeckera/Hanseniaspora and Zygosaccharomyces. Moreover, Kpkt maintains its killer activity in grape must for at least 14 days under winemaking conditions, thus suggesting its use against spoilage yeast in wine making and the sweet beverage industry. Here, the aim was to explore the possibility of high production of Kpkt for biotechnological exploitation. Molecular tools for heterologous production of Kpkt in Komagataella phaffii GS115 were developed, and two recombinant clones that produce up to 23 mg/L recombinant Kpkt (rKpkt) were obtained. Similar to native Kpkt, rKpkt has β-glucanase and killer activities. Moreover, it shows a wider spectrum of action with respect to native Kpkt. This includes effects on Dekkera bruxellensis, a spoilage yeast of interest not only in wine making, but also for the biofuel industry, thus widening the potential applications of this rKpkt.

Adaptive Response and Tolerance to Acetic Acid in Saccharomyces cerevisiae and Zygosaccharomyces bailii: A Physiological Genomics Perspective.

Science.gov (United States)

Palma, Margarida; Guerreiro, Joana F; Sá-Correia, Isabel

2018-01-01

Acetic acid is an important microbial growth inhibitor in the food industry; it is used as a preservative in foods and beverages and is produced during normal yeast metabolism in biotechnological processes. Acetic acid is also a major inhibitory compound present in lignocellulosic hydrolysates affecting the use of this promising carbon source for sustainable bioprocesses. Although the molecular mechanisms underlying Saccharomyces cerevisiae response and adaptation to acetic acid have been studied for years, only recently they have been examined in more detail in Zygosaccharomyces bailii . However, due to its remarkable tolerance to acetic acid and other weak acids this yeast species is a major threat in the spoilage of acidic foods and beverages and considered as an interesting alternative cell factory in Biotechnology. This review paper emphasizes genome-wide strategies that are providing global insights into the molecular targets, signaling pathways and mechanisms behind S. cerevisiae and Z. bailii tolerance to acetic acid, and extends this information to other weak acids whenever relevant. Such comprehensive perspective and the knowledge gathered in these two yeast species allowed the identification of candidate molecular targets, either for the design of effective strategies to overcome yeast spoilage in acidic foods and beverages, or for the rational genome engineering to construct more robust industrial strains. Examples of successful applications are provided.

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

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...

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 ...

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 ...

21 CFR 172.325 - Bakers yeast protein.

Science.gov (United States)

2010-04-01

... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.325 Bakers yeast protein. Bakers yeast protein may be...

The carbon consumption pattern of the spoilage yeast Brettanomyces bruxellensis in synthetic wine-like medium.

Science.gov (United States)

Smith, Brendan D; Divol, Benoit

2018-08-01

The wine matrix contains limited carbon compounds to sustain microbial life. Brettanomyces bruxellensis is one of very few yeast species that has adapted to this environment. Indeed, the presence of growth-inhibiting compounds and conditions do not prevent its proliferation. Literature regarding the nutritional requirements of this yeast is surprisingly poor, given the observation that B. bruxellensis produces biomass with apparently less nutrients than other yeasts. In this study, various carbon sources were screened in a synthetic wine medium, under anaerobic and semi-aerobic growth conditions, in order to determine which compounds B. bruxellensis assimilates. Slight differences were observed between strains but overall, B. bruxellensis produced biomass from limited nutrients consumed in a specific order regardless of the oxygen conditions. Upon initial consumption of the simple sugars, B. bruxellensis was able to remain viable, by concurrently utilising ethanol (only in the presence of oxygen) and malic acid. Although initially beneficial, oxygen was found detrimental in the long term. Formation of volatile phenols occurred during the consumption of the sugars but not as a mechanism to help correct the redox imbalance. The study confirms that B. bruxellensis is able to survive using limited amount of nutrients, making this yeast a challenge for winemakers. Copyright © 2017 Elsevier Ltd. All rights reserved.

21 CFR 573.750 - Pichia pastoris dried yeast.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Pichia pastoris dried yeast. 573.750 Section 573... Food Additive Listing § 573.750 Pichia pastoris dried yeast. (a) Identity. The food additive Pichia pastoris dried yeast may be used in feed formulations of broiler chickens as a source of protein not to...

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

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 ...

The euryhaline yeast Debaryomyces hansenii has two catalase genes encoding enzymes with differential activity profile.

Science.gov (United States)

Segal-Kischinevzky, Claudia; Rodarte-Murguía, Beatriz; Valdés-López, Victor; Mendoza-Hernández, Guillermo; González, Alicia; Alba-Lois, Luisa

2011-03-01

Debaryomyces hansenii is a spoilage yeast able to grow in a variety of ecological niches, from seawater to dairy products. Results presented in this article show that (i) D. hansenii has an inherent resistance to H2O2 which could be attributed to the fact that this yeast has a basal catalase activity which is several-fold higher than that observed in Saccharomyces cerevisiae under the same culture conditions, (ii) D. hansenii has two genes (DhCTA1 and DhCTT1) encoding two catalase isozymes with a differential enzymatic activity profile which is not strictly correlated with a differential expression profile of the encoding genes.

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

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, 10(8) to 10(9) CFU/g. AHL-producing bacteria (Enterobacteriaceae and pseudomonads) were isolated from commercial sprouts, and strains that were both proteolytic and pectinolytic were capable of causing soft-rot spoilage in bean...... 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...

Beer spoilage bacteria and hop resistance.

Science.gov (United States)

Sakamoto, Kanta; Konings, Wil N

2003-12-31

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 Megasphaera cerevisiae. They can spoil beer by turbidity, acidity and the production of unfavorable smell such as diacetyl or hydrogen sulfide. For the microbiological control, many advanced biotechnological techniques such as immunoassay and polymerase chain reaction (PCR) have been applied in place of the conventional and time-consuming method of incubation on culture media. Subsequently, a method is needed to determine whether the detected bacterium is capable of growing in beer or not. In lactic acid bacteria, hop resistance is crucial for their ability to grow in beer. Hop compounds, mainly iso-alpha-acids in beer, have antibacterial activity against Gram-positive bacteria. They act as ionophores which dissipate the pH gradient across the cytoplasmic membrane and reduce the proton motive force (pmf). Consequently, the pmf-dependent nutrient uptake is hampered, resulting in cell death. The hop-resistance mechanisms in lactic acid bacteria have been investigated. HorA was found to excrete hop compounds in an ATP-dependent manner from the cell membrane to outer medium. Additionally, increased proton pumping by the membrane bound H(+)-ATPase contributes to hop resistance. To energize such ATP-dependent transporters hop-resistant cells contain larger ATP pools than hop-sensitive cells. Furthermore, a pmf-dependent hop transporter was recently presented. Understanding the hop-resistance mechanisms has enabled the development of rapid methods to discriminate beer spoilage strains from nonspoilers. The horA-PCR method has been applied for bacterial control in breweries. Also, a discrimination method was developed based on ATP pool measurement in lactobacillus cells. However

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.

Genetics of Yeasts

Science.gov (United States)

Querol, Amparo; Fernández-Espinar, M. Teresa; Belloch, Carmela

The use of yeasts in biotechnology processes dates back to ancient days. Before 7000 BC, beer was produced in Sumeria. Wine was made in Assyria in 3500 BC, and ancient Rome had over 250 bakeries, which were making leavened bread by 100 BC. And milk has been made into Kefyr and Koumiss in Asia for many centuries (Demain, Phaff, & Kurtzman, 1999). However, the importance of yeast in the food and beverage industries was only realized about 1860, when their role in food manufacturing became evident.

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...

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.

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.

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)

Brewing characteristics of piezosensitive sake yeasts

Science.gov (United States)

Nomura, Kazuki; Hoshino, Hirofumi; Igoshi, Kazuaki; Onozuka, Haruka; Tanaka, Erika; Hayashi, Mayumi; Yamazaki, Harutake; Takaku, Hiroaki; Iguchi, Akinori; Shigematsu, Toru

2018-04-01

Application of high hydrostatic pressure (HHP) treatment to food processing is expected as a non-thermal fermentation regulation technology that supresses over fermentation. However, the yeast Saccharomyces cerevisiae used for Japanese rice wine (sake) brewing shows high tolerance to HHP. Therefore, we aimed to generate pressure-sensitive (piezosensitive) sake yeast strains by mating sake with piezosensitive yeast strains to establish an HHP fermentation regulation technology and extend the shelf life of fermented foods. The results of phenotypic analyses showed that the generated yeast strains were piezosensitive and exhibited similar fermentation ability compared with the original sake yeast strain. In addition, primary properties of sake brewed using these strains, such as ethanol concentration, sake meter value and sake flavor compounds, were almost equivalent to those obtained using the sake yeast strain. These results suggest that the piezosensitive strains exhibit brewing characteristics essentially equivalent to those of the sake yeast strain.

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

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.

Yeast diversity and native vigor for flavor phenotypes.

Science.gov (United States)

Carrau, Francisco; Gaggero, Carina; Aguilar, Pablo S

2015-03-01

Saccharomyces cerevisiae, the yeast used widely for beer, bread, cider, and wine production, is the most resourceful eukaryotic model used for genetic engineering. A typical concern about using engineered yeasts for food production might be negative consumer perception of genetically modified organisms. However, we believe the true pitfall of using genetically modified yeasts is their limited capacity to either refine or improve the sensory properties of fermented foods under real production conditions. Alternatively, yeast diversity screening to improve the aroma and flavors could offer groundbreaking opportunities in food biotechnology. We propose a 'Yeast Flavor Diversity Screening' strategy which integrates knowledge from sensory analysis and natural whole-genome evolution with information about flavor metabolic networks and their regulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

Functional genomics for food microbiology: Molecular mechanisms of weak organic acid preservative adaptation in yeast

NARCIS (Netherlands)

Brul, S.; Kallemeijn, W.; Smits, G.

2008-01-01

The recent era of genomics has offered tremendous possibilities to biology. This concise review describes the possibilities of applying (functional) genomics studies to the field of microbial food stability. In doing so, the studies on weak-organic-acid stress response in yeast are discussed by way

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

Purification and characterization of antifungal compounds from Lactobacillus plantarum HD1 isolated from kimchi.

Science.gov (United States)

Ryu, Eun Hye; Yang, Eun Ju; Woo, Eun Rhan; Chang, Hae Choon

2014-08-01

Strain HD1 with antifungal activity was isolated from kimchi and identified as Lactobacillus plantarum. Antifungal compounds from Lb. plantarum HD1 were active against food- and feed-borne filamentous fungi and yeasts in a spot-on-the-lawn assay. Antifungal activity of Lb. plantarum HD1 was stronger against filamentous fungi than yeast. Antifungal compounds were purified using solid phase extraction (SPE) and recycling preparative-HPLC. Structures of the antifungal compounds were elucidated by electrospray ionization-mass spectrometry and nuclear magnetic resonance. Active compounds from Lb. plantarum HD1 were identified as 5-oxododecanoic acid (MW 214), 3-hydroxy decanoic acid (MW 188), and 3-hydroxy-5-dodecenoic acid (MW 214). To investigate the potential application of these antifungal compounds for reduction of fungal spoilage in foods, Korean draft rice wine was used as a food model. White film-forming yeasts were observed in control draft rice wine after 11 days of incubation. However, film-forming yeasts were not observed in draft rice wine treated with SPE-prepared culture supernatant of Lb. plantarum HD1 (equivalent to 2.5% addition of culture supernatant) until 27 days of incubation. The addition of antifungal compounds to Korean draft rice wine extended shelf-life up to 27 days at 10 °C without any sterilization process. Therefore, the antifungal activity of Lb. plantarum HD1 may lead to the development of powerful biopreservative systems capable of preventing food- and feed-borne fungal spoilage. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

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.

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

Application of low dose radiation for preservation of sea foods

International Nuclear Information System (INIS)

Venugopal, V.; Nair, P.M.

1994-01-01

Treatment of food with low doses of gamma radiation has been recognized to have two main advantages. These consist of: (1) improvement of food safety by elimination of pathogens and (2) reduction of microbial spoilage and extension of shelf life of perishable items by reducing the number of viable spoilage organisms. Studies during the last few decades have conclusively proved the beneficial effects of radiation with respect to fishery products. The three potential areas of application to fish products include: (i) radurization for shelf life extension (ii) radicidation to eliminate food borne pathogens in the products and (iii) radiation treatment to dried products to control insects

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.

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.

Assessing genetic diversity among Brettanomyces yeasts by DNA fingerprinting and whole-genome sequencing.

Science.gov (United States)

Crauwels, Sam; Zhu, Bo; Steensels, Jan; Busschaert, Pieter; De Samblanx, Gorik; Marchal, Kathleen; Willems, Kris A; Verstrepen, Kevin J; Lievens, Bart

2014-07-01

Brettanomyces yeasts, with the species Brettanomyces (Dekkera) bruxellensis being the most important one, are generally reported to be spoilage yeasts in the beer and wine industry due to the production of phenolic off flavors. However, B. bruxellensis is also known to be a beneficial contributor in certain fermentation processes, such as the production of certain specialty beers. Nevertheless, despite its economic importance, Brettanomyces yeasts remain poorly understood at the genetic and genomic levels. In this study, the genetic relationship between more than 50 Brettanomyces strains from all presently known species and from several sources was studied using a combination of DNA fingerprinting techniques. This revealed an intriguing correlation between the B. bruxellensis fingerprints and the respective isolation source. To further explore this relationship, we sequenced a (beneficial) beer isolate of B. bruxellensis (VIB X9085; ST05.12/22) and compared its genome sequence with the genome sequences of two wine spoilage strains (AWRI 1499 and CBS 2499). ST05.12/22 was found to be substantially different from both wine strains, especially at the level of single nucleotide polymorphisms (SNPs). In addition, there were major differences in the genome structures between the strains investigated, including the presence of large duplications and deletions. Gene content analysis revealed the presence of 20 genes which were present in both wine strains but absent in the beer strain, including many genes involved in carbon and nitrogen metabolism, and vice versa, no genes that were missing in both AWRI 1499 and CBS 2499 were found in ST05.12/22. Together, this study provides tools to discriminate Brettanomyces strains and provides a first glimpse at the genetic diversity and genome plasticity of B. bruxellensis. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

21 CFR 184.1983 - Bakers yeast extract.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Bakers yeast extract. 184.1983 Section 184.1983... Listing of Specific Substances Affirmed as GRAS § 184.1983 Bakers yeast extract. (a) Bakers yeast extract... a selected strain of yeast, Saccharomyces cerevisiae. It may be concentrated or dried. (b) The...

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

Bacterial spoilage profiles to identify irradiated fish

International Nuclear Information System (INIS)

Alur, M.D.; Venugopal, V.; Nerkar, D.P.; Nair, P.M.

1991-01-01

Effects of low dose gamma-irradiation of fish product on spoilage potentials of bacteria (Aeromonas hydrophila, Salmonella typhimurium, Bacillus megaterium, and Pseudomonas marinoglutinosa) and mixed flora were examined for ability to proliferate in radurized fish and produce volatile acids (TVA) and bases (TVBN). Bacteria proliferated well in unirradiated and irradiated fish, but formation of VA and VB were lower in irradiated than unirradiated counterparts. This was found in Bombay duck, Indian mackerel, white pomfret, seer and shrimp gamma-irradiated at 0 to 5 kGy under ice. TVA and TVBN produced by the organisms or mixed flora from fish were only 30-50% those of controls. A method for identifying radiation-processed fish could evolve based on lower susceptibility of irradiated fish to bacterial spoilage

Metabolic Profiling of Food Protective Cultures by in vitro NMR Spectroscopy

DEFF Research Database (Denmark)

Ebrahimi, Parvaneh

Food spoilage is of major concern to the food industry, because it leads to considerable economic losses, a deteriorated environmental food-print, and to possible public health hazards. In order to limit food spoilage, research on the preservation of food products has always received particular......-called protective cultures) has unexploited potential to inhibit the growth of pathogenic microorganisms and enhance the shelf life of the final food product. In order to apply biopreservation in food products effectively, detailed knowledge on the metabolism of protective cultures is required. The present Ph......D project is mainly focused on the application of in vitro NMR spectroscopy for studying the metabolism of protective cultures. As an important part of this work, an analytical protocol was developed for realtime in vitro NMR measurements of bacterial fermentation, which includes guidelines from the sample...

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.

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.

Food preservation by irradiation

Energy Technology Data Exchange (ETDEWEB)

NONE

1978-02-15

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

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

Study on spoilage capability and VBNC state formation and recovery of Lactobacillus plantarum.

Science.gov (United States)

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

2017-09-01

The present study aimed at investigating the capability of L. plantarum strain BM-LP14723 to enter into and recover from the viable but nonculturable (VBNC) state and to cause beer spoilage. VBNC state was induced by incubating in beer with subculturing or low temperature treatment. Culturable, total, and viable cells numbers were assessed by MRS agar plate counting, acridine orange direct counting, and Live/Dead BacLight bacterial viability kit, respectively. Organic acids concentrations were measured by reversed-phase high performance liquid chromatography. VBNC L. plantarum cells were detected after 189 ± 1.9 days low temperature treatment or 29 ± 0.7 subcultures in beer. The VBNC L. plantarum retained spoilage capability. Addition of catalase is an effective method for the recovery of the VBNC L. plantarum cells. L. plantarum strain BM-LP14723 is capable of entering into and recovery from the VBNC state and maintained spoilage capability. The current study presented that beer-spoilage L. plantarum can hide both in breweries and during transporting and marketing process and thus lead to beer-spoilage incidents. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

OpenAIRE

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

2015-01-01

eLife digest Many microbes?including bacteria and fungi?can affect the food and drink we consume, for better and for worse. Some spoil food, making it less tasty or even harmful to health. However, microbes can also be important ingredients: for example, yeast ferments malted barley sugars to make the alcohol and flavor of beer. Nowadays, many beers are made under carefully controlled conditions, where the only microbes in the beer should be the strain of yeast added to the barley sugars. A m...

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.

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

International Nuclear Information System (INIS)

Perez Espitia, Paula Judith; Ferreira Soares, Nilda de Fátima; Teófilo, Reinaldo F.; Vitor, Débora M.; Reis Coimbra, Jane Sélia dos; Andrade, Nélio José de; Sousa, Frederico B. de; Sinisterra, Rubén D.; Medeiros, Eber Antonio Alves

2013-01-01

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 4 P 2 O 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.

Evaluation of fingerprinting techniques to assess genotype variation among Zygosaccharomyces strains.

Science.gov (United States)

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

2018-06-01

Molecular typing techniques are key tools in surveillance of food spoilage yeasts, in investigations on intra-species population diversity, and in tracing selected starters during fermentation. Unlike previous works on strain typing of Zygosaccharomyces spoilage species, here Zygosaccharomyces mellis and the Zygosaccharoymces rouxii complex yeasts, which include Z. rouxii, Zygosaccharomyces sapae, and a mosaic lineage (ML) of putatively hybrids, were evaluated by three typing methods for intra- and inter-species resolution. Overall these yeasts are relevant for food fermentation and spoilage, but are quite difficult to discriminate at strain and species level as they evolved by reticulation. A pool of 76 strains from different sources were typed by M13 and (GTG) 5 MSP-PCR fingerprinting and PCR-RFLP of ribosomal intergenic spacer region (IGS). We demonstrated that M13 overcame (GTG) 5 fingerprinting to group Z. sapae, Z. rouxii, Z. mellis and the ML isolates in congruent distinct clusters. Even if (GTG) 5 primer yielded a number of DNA fingerprints comparable with those obtained by M13 primer, it failed to discriminate Z. sapae, Z. mellis and Z. rouxii at species level. Clustering of IGS RFLP patterns obtained with three endonucleases produced groups congruent with species assignment and highlighted intra-species diversity similar to that observed by M13 fingerprinting. However, IGS PCR amplification failed for 14 ML and 6 Z. mellis strains under the experimental conditions tested here, indicating that this marker could be less easy to use in fast typing protocol. Finally, our results posit that the genetic diversity within Z. sapae and Z. mellis could be shaped by isolation source. The information generated in this study would facilitate the monitoring of these yeasts during food processing and storage, and provides preliminary evidences about Z. sapae and Z. mellis intra-species diversity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Taming wild yeast: potential of conventional and nonconventional yeasts in industrial fermentations.

Science.gov (United States)

Steensels, Jan; Verstrepen, Kevin J

2014-01-01

Yeasts are the main driving force behind several industrial food fermentation processes, including the production of beer, wine, sake, bread, and chocolate. Historically, these processes developed from uncontrolled, spontaneous fermentation reactions that rely on a complex mixture of microbes present in the environment. Because such spontaneous processes are generally inconsistent and inefficient and often lead to the formation of off-flavors, most of today's industrial production utilizes defined starter cultures, often consisting of a specific domesticated strain of Saccharomyces cerevisiae, S. bayanus, or S. pastorianus. Although this practice greatly improved process consistency, efficiency, and overall quality, it also limited the sensorial complexity of the end product. In this review, we discuss how Saccharomyces yeasts were domesticated to become the main workhorse of food fermentations, and we investigate the potential and selection of nonconventional yeasts that are often found in spontaneous fermentations, such as Brettanomyces, Hanseniaspora, and Pichia spp.

21 CFR 172.590 - Yeast-malt sprout extract.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Yeast-malt sprout extract. 172.590 Section 172.590... CONSUMPTION Flavoring Agents and Related Substances § 172.590 Yeast-malt sprout extract. Yeast-malt sprout... prescribed conditions: (a) The additive is produced by partial hydrolysis of yeast extract (derived from...

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.

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.

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

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.

Autoinducer-2-like activity associated with foods and its interaction with food additives.

Science.gov (United States)

Lu, Lingeng; Hume, Michael E; Pillai, Suresh D

2004-07-01

The autoinducer-2 (AI-2) molecule produced by bacteria as part of quorum sensing is considered to be a universal inducer signal in bacteria because it reportedly influences gene expression in a variety of both gram-negative and gram-positive bacteria. The objective of this study was to determine whether selected fresh produce and processed foods have AI-2-like activity and whether specific food additives can act as AI-2 mimics and result in AI-2-like activity. The luminescence-based response of the reporter strain Vibrio harveyi BB170 was used as the basis for determining AI-2 activity in the selected foods and food ingredients. Maximum AI-2 activity was seen on the frozen fish sample (203-fold, compared with the negative control) followed by tomato, cantaloupe, carrots, tofu, and milk samples. Interestingly, some samples were capable of inhibiting AI-2 activity. Turkey patties showed the highest inhibition (99.8% compared with the positive control) followed by chicken breast (97.5%), homemade cheeses (93.7%), beef steak (90.6%), and beef patties (84.4%). AI-2 activity was almost totally inhibited by sodium propionate, whereas sodium benzoate caused 93.3% inhibition, compared with 75% inhibition by sodium acetate. Sodium nitrate did not have any appreciable effect, even at 200 ppm. Understanding the relationships that exist between AI-2 activity on foods and the ecology of pathogens and food spoilage bacteria on foods could yield clues about factors controlling food spoilage and pathogen virulence.

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

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

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)

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)

Development of a novel colorimetric sensor based on alginate beads for monitoring rainbow trout spoilage.

Science.gov (United States)

Majdinasab, Marjan; Hosseini, Seyed Mohammad Hashem; Sepidname, Marziyeh; Negahdarifar, Manizheh; Li, Peiwu

2018-05-01

Alginate is a non-toxic, renewable, and linear copolymer obtained from the brown algae Laminaria digitata that can be easily shaped into beads. Its good gel forming properties have made it useful for entrapping food and pharmaceutical ingredients. In this study, alginate beads were used in a novel application as a colorimetric sensor in food intelligent packaging. Colorimetric sensor was developed through entrapping red cabbage extract as a pH indicator in alginate beads. The pH indicator beads were used in rainbow trout packaging for monitoring fillets spoilage. Color change of beads during fish storage was measured using the CIELab method. The alginate bead colorimetric sensor is validated by measuring total volatile basic nitrogen (TVB-N) levels and microbial populations in fish samples. Moreover, peroxide value (PV) and thiobarbituric acid reactive substances (TBARS) were evaluated during storage. Results indicated that increasing the bacterial population during storage and production of proteolytic enzymes resulted in protein degradation, accumulation of volatile amine compounds, increase in the pH and finally color change of alginate beads. The values of TVB-N, pH, PV and TBARS increased with time of storage. The results of TVB-N and microbial growth were in accordance with color change of beads and CIELab data. Therefore, the proposed system enjoys a high sensitivity to pH variations and is capable of monitoring the spoilage of fish or other protein-rich products through its wide range of color changes. The alginate beads containing the red cabbage extract can, thus, be used as a low-cost colorimetric sensor for intelligent packaging applications.

Spoilage and shelf-life extension of fresh fish and shellfish.

Science.gov (United States)

Ashie, I N; Smith, J P; Simpson, B K

1996-01-01

Fresh fish and shellfish are highly perishable products due to their biological composition. Under normal refrigerated storage conditions, the shelf life of these products is limited by enzymatic and microbiological spoilage. However, with increasing consumer demands for fresh products with extended shelf life and increasing energy costs associated with freezing and frozen storage, the fish-processing industry is actively seeking alternative methods of shelf life preservation and marketability of fresh, refrigerated fish and at the same time economizing on energy costs. Additional methods that could fulfill these objectives include chemical decontamination, low-dose irradiation, ultra-high pressure, and modified atmosphere packaging (MAP). This review focuses on the biochemical and microbiological composition of fresh fish/shellfish, the spoilage patterns in these products, factors influencing spoilage, and the combination treatments that can be used in conjunction with refrigeration to extend the shelf life and keeping quality of fresh fish/shellfish. The safety concerns of minimally processed/MAP fish, specifically with respect to the growth of Clostridium botulinum type E, is also addressed.

[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.

Utilization of spent brewer’s yeast Saccharomyces cerevisiae for the production of yeast enzymatic hydrolysate

Directory of Open Access Journals (Sweden)

M Bayarjargal

2014-09-01

Full Text Available Spent brewer’s yeast (Saccharomyces cerevisiae is a rich source of protein, vitamins and widely used as a raw material for production of food supplements. The autolysis and enzymatic treatment of spent brewer’s yeast using Pancreatin (2.5% and Flavourzyme (2.5% were performed at 45 °C and 50 °C, respectively. The autolysis and hydrolysis processes were evaluated by determining a soluble solids, soluble protein concentration and α-amino nitrogen content in a reaction mixture. The yield of pancreatic digest and α-amino nitrogen content was high in comparison with autolysis and Flavourzyme treatment. The total solids recovery in dry Yeast hydrolysate was about 50%, a protein and α-amino nitrogen content was 55.9 and 4.8%, respectively. These results show the possibility of utilizing the spent brewer’s yeast as hydrolysate using hydrolytic enzymes and use it as a food supplement after biological experiments.DOI: http://dx.doi.org/10.5564/mjc.v12i0.179 Mongolian Journal of Chemistry Vol.12 2011: 88-91

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

Evaluation of Petrifilm Lactic Acid Bacteria Plates for Counting Lactic Acid Bacteria in Food.

Science.gov (United States)

Kanagawa, Satomi; Ohshima, Chihiro; Takahashi, Hajime; Burenqiqige; Kikuchi, Misato; Sato, Fumina; Nakamura, Ayaka; Mohamed, Shimaa M; Kuda, Takashi; Kimura, Bon

2018-06-01

Although lactic acid bacteria (LAB) are used widely as starter cultures in the production of fermented foods, they are also responsible for food decay and deterioration. The undesirable growth of LAB in food causes spoilage, discoloration, and slime formation. Because of these adverse effects, food companies test for the presence of LAB in production areas and processed foods and consistently monitor the behavior of these bacteria. The 3M Petrifilm LAB Count Plates have recently been launched as a time-saving and simple-to-use plate designed for detecting and quantifying LAB. This study compares the abilities of Petrifilm LAB Count Plates and the de Man Rogosa Sharpe (MRS) agar medium to determine the LAB count in a variety of foods and swab samples collected from a food production area. Bacterial strains isolated from Petrifilm LAB Count Plates were identified by 16S rDNA sequence analysis to confirm the specificity of these plates for LAB. The results showed no significant difference in bacterial counts measured by using Petrifilm LAB Count Plates and MRS medium. Furthermore, all colonies growing on Petrifilm LAB Count Plates were confirmed to be LAB, while yeast colonies also formed in MRS medium. Petrifilm LAB Count Plates eliminated the plate preparation and plate inoculation steps, and the cultures could be started as soon as a diluted food sample was available. Food companies are required to establish quality controls and perform tests to check the quality of food products; the use of Petrifilm LAB Count Plates can simplify this testing process for food companies.

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.)

21 CFR 73.355 - Phaffia yeast.

Science.gov (United States)

2010-04-01

... stabilized color additive mixture. Color additive mixtures for fish feed use made with phaffia yeast may... additive mixtures for coloring foods. (b) Specifications. Phaffia yeast shall conform to the following... § 501.4 of this chapter. (3) The presence of the color additive in salmonid fish that have been fed...

The viable but nonculturable state induction and genomic analyses of Lactobacillus casei BM-LC14617, a beer-spoilage bacterium.

Science.gov (United States)

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

2017-10-01

This study aimed to investigate the viable but nonculturable (VBNC) state and genomic features of a beer-spoilage strain, Lactobacillus caseiBM-LC14617. Induction on the VBNC state of L. casei strain BM-LC14617 was conducted by both low-temperature storage and continuous passage in beer, and formation of VBNC state was detected after 196 ± 3.3 days and 32 ± 1.6 subcultures, respectively. Resuscitation of VBNC cells was successfully induced by addition of catalase, and culturable, VBNC, and resuscitated cells shared similar beer-spoilage capability. Whole genome sequencing was performed, and out of a total of 3,964 predicted genes, several potential VBNC and beer-spoilage-associated genes were identified. L. casei is capable of entering into and resuscitating from the VBNC state and possesses beer-spoilage capability. The genomic characterization yield insightful elucidation of VBNC state for L. casei. This study represents the first evidence on VBNC state induction of L. casei and beer-spoilage capability of VBNC and resuscitated cells. Also, this is the first genomic characterization of L. casei as a beer-spoilage bacterium. The current study may aid in further study on L. casei and other beer-spoilage bacteria, and guide the prevention and control of beer spoilage. © 2017 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

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.

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 ...

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...

Improving industrial yeast strains: exploiting natural and artificial diversity

Science.gov (United States)

Steensels, Jan; Snoek, Tim; Meersman, Esther; Nicolino, Martina Picca; Voordeckers, Karin; Verstrepen, Kevin J

2014-01-01

Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as ‘global transcription machinery engineering’ (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. PMID:24724938

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

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.

Biotechnology of non-Saccharomyces yeasts--the ascomycetes.

Science.gov (United States)

Johnson, Eric A

2013-01-01

Saccharomyces cerevisiae and several other yeast species are among the most important groups of biotechnological organisms. S. cerevisiae and closely related ascomycetous yeasts are the major producer of biotechnology products worldwide, exceeding other groups of industrial microorganisms in productivity and economic revenues. Traditional industrial attributes of the S. cerevisiae group include their primary roles in food fermentations such as beers, cider, wines, sake, distilled spirits, bakery products, cheese, sausages, and other fermented foods. Other long-standing industrial processes involving S. cerevisae yeasts are production of fuel ethanol, single-cell protein (SCP), feeds and fodder, industrial enzymes, and small molecular weight metabolites. More recently, non-Saccharomyces yeasts (non-conventional yeasts) have been utilized as industrial organisms for a variety of biotechnological roles. Non-Saccharomyces yeasts are increasingly being used as hosts for expression of proteins, biocatalysts and multi-enzyme pathways for the synthesis of fine chemicals and small molecular weight compounds of medicinal and nutritional importance. Non-Saccharomyces yeasts also have important roles in agriculture as agents of biocontrol, bioremediation, and as indicators of environmental quality. Several of these products and processes have reached commercial utility, while others are in advanced development. The objective of this mini-review is to describe processes currently used by industry and those in developmental stages and close to commercialization primarily from non-Saccharomyces yeasts with an emphasis on new opportunities. The utility of S. cerevisiae in heterologous production of selected products is also described.

671-nm microsystem diode laser based on portable Raman sensor device for in-situ identification of meat spoilage

Science.gov (United States)

Sowoidnich, Kay; Schmidt, Heinar; Schwägele, Fredi; Kronfeldt, Heinz-Detlef

2011-05-01

Based on a miniaturized optical bench with attached 671 nm microsystem diode laser we present a portable Raman system for the rapid in-situ characterization of meat spoilage. It consists of a handheld sensor head (dimensions: 210 x 240 x 60 mm3) for Raman signal excitation and collection including the Raman optical bench, a laser driver, and a battery pack. The backscattered Raman radiation from the sample is analyzed by means of a custom-designed miniature spectrometer (dimensions: 200 x 190 x 70 mm3) with a resolution of 8 cm-1 which is fiber-optically coupled to the sensor head. A netbook is used to control the detector and for data recording. Selected cuts from pork (musculus longissimus dorsi and ham) stored refrigerated at 5 °C were investigated in timedependent measurement series up to three weeks to assess the suitability of the system for the rapid detection of meat spoilage. Using a laser power of 100 mW at the sample meat spectra can be obtained with typical integration times of 5 - 10 seconds. The complex spectra were analyzed by the multivariate statistical tool PCA (principal components analysis) to determine the spectral changes occurring during the storage period. Additionally, the Raman data were correlated with reference analyses performed in parallel. In that way, a distinction between fresh and spoiled meat can be found in the time slot of 7 - 8 days after slaughter. The applicability of the system for the rapid spoilage detection of meat and other food products will be discussed.

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

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.

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.

Microbiological, chemical and sensory spoilage analysis of raw Atlantic cod (Gadus morhua) stored under modified atmospheres.

Science.gov (United States)

Kuuliala, L; Al Hage, Y; Ioannidis, A-G; Sader, M; Kerckhof, F-M; Vanderroost, M; Boon, N; De Baets, B; De Meulenaer, B; Ragaert, P; Devlieghere, F

2018-04-01

During fish spoilage, microbial metabolism leads to the production of volatile organic compounds (VOCs), characteristic off-odors and eventual consumer rejection. The aim of the present study was to contribute to the development of intelligent packaging technologies by identifying and quantifying VOCs that indicate spoilage of raw Atlantic cod (Gadus morhua) under atmospheres (%v/v CO 2 /O 2 /N 2 ) 60/40/0, 60/5/35 and air. Spoilage was examined by microbiological, chemical and sensory analyses over storage time at 4 or 8 °C. Selected-ion flow-tube mass spectrometry (SIFT-MS) was used for quantifying selected VOCs and amplicon sequencing of the 16S rRNA gene was used for the characterization of the cod microbiota. OTUs classified within the Photobacterium genus increased in relative abundance over time under all storage conditions, suggesting that Photobacterium contributed to spoilage and VOC production. The onset of exponential VOC concentration increase and sensory rejection occurred at high total plate counts (7-7.5 log). Monitoring of early spoilage thus calls for sensitivity for low VOC concentrations. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Fractals and foods.

Science.gov (United States)

Peleg, M

1993-01-01

Fractal geometry and related concepts have had only a very minor impact on food research. The very few reported food applications deal mainly with the characterization of the contours of agglomerated instant coffee particles, the surface morphology of treated starch particles, the microstructure of casein gels viewed as a product limited diffusion aggregation, and the jagged mechanical signatures of crunchy dry foods. Fractal geometry describes objects having morphological features that are scale invariant. A demonstration of the self-similarity of fractal objects can be found in the familiar morphology of cauliflower and broccoli, both foods. Processes regulated by nonlinear dynamics can exhibit a chaotic behavior that has fractal characteristics. Examples are mixing of viscous fluids, turbulence, crystallization, agglomeration, diffusion, and possibly food spoilage.

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

Biotechnology of non-Saccharomyces yeasts-the basidiomycetes.

Science.gov (United States)

Johnson, Eric A

2013-09-01

Yeasts are the major producer of biotechnology products worldwide, exceeding production in capacity and economic revenues of other groups of industrial microorganisms. Yeasts have wide-ranging fundamental and industrial importance in scientific, food, medical, and agricultural disciplines (Fig. 1). Saccharomyces is the most important genus of yeast from fundamental and applied perspectives and has been expansively studied. Non-Saccharomyces yeasts (non-conventional yeasts) including members of the Ascomycetes and Basidiomycetes also have substantial current utility and potential applicability in biotechnology. In an earlier mini-review, "Biotechnology of non-Saccharomyces yeasts-the ascomycetes" (Johnson Appl Microb Biotechnol 97: 503-517, 2013), the extensive biotechnological utility and potential of ascomycetous yeasts are described. Ascomycetous yeasts are particularly important in food and ethanol formation, production of single-cell protein, feeds and fodder, heterologous production of proteins and enzymes, and as model and fundamental organisms for the delineation of genes and their function in mammalian and human metabolism and disease processes. In contrast, the roles of basidiomycetous yeasts in biotechnology have mainly been evaluated only in the past few decades and compared to the ascomycetous yeasts and currently have limited industrial utility. From a biotechnology perspective, the basidiomycetous yeasts are known mainly for the production of enzymes used in pharmaceutical and chemical synthesis, for production of certain classes of primary and secondary metabolites such as terpenoids and carotenoids, for aerobic catabolism of complex carbon sources, and for bioremediation of environmental pollutants and xenotoxicants. Notwithstanding, the basidiomycetous yeasts appear to have considerable potential in biotechnology owing to their catabolic utilities, formation of enzymes acting on recalcitrant substrates, and through the production of unique primary

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.

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.

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

Improving industrial yeast strains: exploiting natural and artificial diversity.

Science.gov (United States)

Steensels, Jan; Snoek, Tim; Meersman, Esther; Picca Nicolino, Martina; Voordeckers, Karin; Verstrepen, Kevin J

2014-09-01

Yeasts have been used for thousands of years to make fermented foods and beverages, such as beer, wine, sake, and bread. However, the choice for a particular yeast strain or species for a specific industrial application is often based on historical, rather than scientific grounds. Moreover, new biotechnological yeast applications, such as the production of second-generation biofuels, confront yeast with environments and challenges that differ from those encountered in traditional food fermentations. Together, this implies that there are interesting opportunities to isolate or generate yeast variants that perform better than the currently used strains. Here, we discuss the different strategies of strain selection and improvement available for both conventional and nonconventional yeasts. Exploiting the existing natural diversity and using techniques such as mutagenesis, protoplast fusion, breeding, genome shuffling and directed evolution to generate artificial diversity, or the use of genetic modification strategies to alter traits in a more targeted way, have led to the selection of superior industrial yeasts. Furthermore, recent technological advances allowed the development of high-throughput techniques, such as 'global transcription machinery engineering' (gTME), to induce genetic variation, providing a new source of yeast genetic diversity. © 2014 The Authors. FEMS Microbiology Reviews published by John Wiley & Sons Ltd on behalf of Federation of European Microbiological Societies.

Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans

OpenAIRE

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

2016-01-01

Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA1...

NMR evaluation of total statin content and HMG-CoA reductase inhibition in red yeast rice (Monascus spp. food supplements

Directory of Open Access Journals (Sweden)

Lachenmeier Dirk W

2012-03-01

Full Text Available Abstract Background Red yeast rice (i.e., rice fermented with Monascus spp., as a food supplement, is claimed to be blood cholesterol-lowering. The red yeast rice constituent monacolin K, also known as lovastatin, is an inhibitor of the hydroxymethylglutaryl-CoA (HMG-CoA reductase. This article aims to develop a sensitive nuclear magnetic resonance (NMR method to determine the total statin content of red yeast rice products. Methods The total statin content was determined by a 400 MHz 1H NMR spectroscopic method, based on the integration of the multiplet at δ 5.37-5.32 ppm of a hydrogen at the hexahydronaphthalene moiety in comparison to an external calibration with lovastatin. The activity of HMG-CoA reductase was measured by a commercial spectrophotometric assay kit. Results The NMR detection limit for total statins was 6 mg/L (equivalent to 0.3 mg/capsule, if two capsules are dissolved in 50 mL ethanol. The relative standard deviations were consistently lower than 11%. The total statin concentrations of five red yeast rice supplements were between 1.5 and 25.2 mg per specified daily dose. A dose-dependent inhibition of the HMG-CoA reductase enzyme activity by the red yeast rice products was demonstrated. Conclusion A simple and direct NMR assay was developed to determine the total statin content in red yeast rice. The assay can be applied for the determination of statin content for the regulatory control of red yeast rice products.

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)

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.

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

OpenAIRE

Mohammad Hashemi; Saber Barkhori-Mehni; Saeed Khanzadi; Mohammad Azizzadeh

2017-01-01

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 h...

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 ...

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.

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.

Broth and agar hop-gradient plates used to evaluate the beer-spoilage potential of Lactobacillus and Pediococcus isolates.

Science.gov (United States)

Haakensen, M; Schubert, A; Ziola, B

2009-03-15

Identification of the beer-spoilage Lactobacillus and Pediococcus bacteria has largely taken two approaches; identification of spoilage-associated genes or identification of specific species of bacteria regardless of ability to grow in beer. The problem with these two approaches is that they are either overly inclusive (i.e., detect all bacteria of a given species regardless of spoilage potential) or overly selective (i.e., rely upon individual, putative spoilage-associated genes). Our goal was to design a method to assess the ability of Lactobacillus and Pediococcus to spoil beer that is independent of speciation or genetic background. In searching for a method by which to differentiate between beer-spoilage bacteria and bacteria that cannot grow in beer, we explored the ability of lactobacilli and pediococci isolates to grow in the presence of varying concentrations of hop-compounds and ethanol in broth medium versus on agar medium. The best method for differentiating between bacteria that can grow in beer and bacteria that do not pose a threat as beer-spoilage organisms was found to be a hop-gradient agar plate containing ethanol. This hop-gradient agar plate technique provides a rapid and simple solution to the dilemma of assessing the ability of Lactobacillus and Pediococcus isolates to grow in beer, and provides new insights into the different strategies used by these bacteria to survive under the stringent conditions of beer.

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.

Combined Effect of Thermosonication and Slightly Acidic Electrolyzed Water to Reduce Foodborne Pathogens and Spoilage Microorganisms on Fresh-cut Kale.

Science.gov (United States)

Mansur, Ahmad Rois; Oh, Deog-Hwan

2015-06-01

This study evaluated the efficacy of individual treatments (thermosonication [TS+DW] and slightly acidic electrolyzed water [SAcEW]) and their combination on reducing Escherichia coli O157:H7, Listeria monocytogenes, and spoilage microorganisms (total bacterial counts [TBC], Enterobacteriaceae, Pseudomonas spp., and yeast and mold counts [YMC]) on fresh-cut kale. For comparison, the antimicrobial efficacies of sodium chlorite (SC; 100 mg/L) and sodium hypochlorite (SH; 100 mg/L) were also evaluated. Each 10 g sample of kale leaves was inoculated to contain approximately 6 log CFU/g of E. coli O157:H7 or L. monocytogenes. Each inoculated or uninoculated samples was then dip treated with deionized water (DW; control), TS+DW, and SAcEW at various treatment conditions (temperature, physicochemical properties, and time) to assess the efficacy of each individual treatment. The efficacy of TS+DW or SAcEW was enhanced at 40 °C for 3 min, with an acoustic energy density of 400 W/L for TS+DW and available chlorine concentration of 5 mg/L for SAcEW. At 40 °C for 3 min, combined treatment of thermosonication 400 W/L and SAcEW 5 mg/L (TS+SAcEW) was more effective in reducing microorganisms compared to the individual treatments (SAcEW, SC, SH, and TS+DW) and combined treatments (TS+SC and TS+SH), which significantly (P 3.24 log CFU/g, respectively. The results suggest that the combined treatment of TS+SAcEW has the potential as a decontamination process in fresh-cut industry. © 2015 Institute of Food Technologists®

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...

Nitrile Metabolizing Yeasts

Science.gov (United States)

Bhalla, Tek Chand; Sharma, Monica; Sharma, Nitya Nand

Nitriles and amides are widely distributed in the biotic and abiotic components of our ecosystem. Nitrile form an important group of organic compounds which find their applications in the synthesis of a large number of compounds used as/in pharmaceutical, cosmetics, plastics, dyes, etc>. Nitriles are mainly hydro-lyzed to corresponding amide/acid in organic chemistry. Industrial and agricultural activities have also lead to release of nitriles and amides into the environment and some of them pose threat to human health. Biocatalysis and biotransformations are increasingly replacing chemical routes of synthesis in organic chemistry as a part of ‘green chemistry’. Nitrile metabolizing organisms or enzymes thus has assumed greater significance in all these years to convert nitriles to amides/ acids. The nitrile metabolizing enzymes are widely present in bacteria, fungi and yeasts. Yeasts metabolize nitriles through nitrilase and/or nitrile hydratase and amidase enzymes. Only few yeasts have been reported to possess aldoxime dehydratase. More than sixty nitrile metabolizing yeast strains have been hither to isolated from cyanide treatment bioreactor, fermented foods and soil. Most of the yeasts contain nitrile hydratase-amidase system for metabolizing nitriles. Transformations of nitriles to amides/acids have been carried out with free and immobilized yeast cells. The nitrilases of Torulopsis candida>and Exophiala oligosperma>R1 are enantioselec-tive and regiospecific respectively. Geotrichum>sp. JR1 grows in the presence of 2M acetonitrile and may have potential for application in bioremediation of nitrile contaminated soil/water. The nitrilase of E. oligosperma>R1 being active at low pH (3-6) has shown promise for the hydroxy acids. Immobilized yeast cells hydrolyze some additional nitriles in comparison to free cells. It is expected that more focus in future will be on purification, characterization, cloning, expression and immobilization of nitrile metabolizing

Comparison of New and Traditional Culture-Dependent Media for Enumerating Foodborne Yeasts and Molds.

Science.gov (United States)

Beuchat, Larry R; Mann, David A

2016-01-01

Fifty-six foods and food ingredients were analyzed for populations of naturally occurring yeasts and molds using Petrifilm rapid yeast and mold (RYM) count plates, Petrifilm yeast and mold (YM) count plates, dichloran rose bengal chloramphenicol (DRBC) agar plates, acidified potato dextrose agar (APDA) plates, and dichloran 18% glycerol (DG18) agar plates. Colonies were counted after incubating plates for 48, 72, and 120 h at 25°C. Of 56 foods in which either yeasts or molds were detected on at least one medium incubated for 120 h, neither yeasts nor molds were detected in 55.4, 73.2, 21.4, 19.6, and 71.4% of foods plated on the five respective media and incubated for 48 h; 10.7, 14.3, 3.6, 1.8, and 19.6% of foods were negative after 72 h, and 3.6, 1.8, 0, 0, and 0% of foods were negative after 120 h. Considering all enumeration media, correlation coefficients were 0.03 to 0.97 at 48 h of incubation; these values increased to 0.75 to 0.99 at 120 h. Coefficients of variation for total yeasts and molds were as high as 30.0, 30.8, and 27.2% at 48, 72, and 120 h, respectively. The general order of performance was DRBC = APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 48 h, DRBC > APDA > RYM Petrifilm > YM Petrifilm ≥ DG18 when plates were incubated for 72 h, and DRBC > APDA > RYM Petrifilm > YM Petrifilm > DG18 when plates were incubated for 120 h. Differences in performance among media are attributed to the diversity of yeasts and molds likely to be present in test foods and differences in nutrient, pH, and water activity requirements for resuscitation of stressed cells and colony development.

Kinetics of spoilage fermentation in radurized fish and optimization of irradiation process

International Nuclear Information System (INIS)

Tukenmez, I.; Ersen, M.S.; Bakioglu, A.T.

1997-01-01

Kinetic studies on radiation-inactivation and the postirradiation growth of spoilage microorganisms during chill storage and their product formation inradurized fish were carried out. Anchovy (Engraulis encrasicholus) samples unirradiated, and those irradiated at 1,2 and 3 kGy doses of gamma radiation were stored at +2 o C for 21 days. Microbiological analyses of mesophilic, psycrophilic and total bacterial counts (TBC) and chemical analyses of trimethylamine (TMA) and total volatile bases (TVB) of the samples were done immediately after irradiation and periodically during storage. Radiation induced inactivations of bacteria were expressed with a first-order decreasing kinetics. A spoilage fermentation modeling was used to evaluate the quality control parameters of radurized fish in which the increase in TBC of survivor microorganisms during storage was described by a first-order growth with a lag phase and the production of TMA and TVB was described by a growth associated product formation. Examinations of the dose effects on the kinetic parameters resulted in that the relation between the product formation rate constants and the irradiation dose represented a parabolic function which was satisfactorily used to determine optimum irradiation dose. Optimum irradiation dose was found 1.719+- 0.471 kGy with TVB data resulting in an extended shelf-life of 15-16 days of fish. It is suggested that the kinetic evaluation method developed in this study may be substitute for or used with the analytical estimate in use comprising microbiological chemical and organoleptic controls for quality assessment and dose optimization of radurization processing of fish and other sea foods.(2 tab s. and 24 refs.)

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

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

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.

Quantitative assessment of the risk of microbial spoilage in foods. Prediction of non-stability at 55 °C caused by Geobacillus stearothermophilus in canned green beans.

Science.gov (United States)

Rigaux, Clémence; André, Stéphane; Albert, Isabelle; Carlin, Frédéric

2014-02-03

Microbial spoilage of canned foods by thermophilic and highly heat-resistant spore-forming bacteria, such as Geobacillus stearothermophilus, is a persistent problem in the food industry. An incubation test at 55 °C for 7 days, then validation of biological stability, is used as an indicator of compliance with good manufacturing practices. We propose a microbial risk assessment model predicting the percentage of non-stability due to G. stearothermophilus in canned green beans manufactured by a French company. The model accounts for initial microbial contaminations of fresh unprocessed green beans with G. stearothermophilus, cross-contaminations in the processing chain, inactivation processes and probability of survival and growth. The sterilization process is modeled by an equivalent heating time depending on sterilization value F₀ and on G. stearothermophilus resistance parameter z(T). Following the recommendations of international organizations, second order Monte-Carlo simulations are used, separately propagating uncertainty and variability on parameters. As a result of the model, the mean predicted non-stability rate is of 0.5%, with a 95% uncertainty interval of [0.1%; 1.2%], which is highly similar to data communicated by the French industry. A sensitivity analysis based on Sobol indices and some scenario tests underline the importance of cross-contamination at the blanching step, in addition to inactivation due to the sterilization process. Copyright © 2013 Elsevier B.V. All rights reserved.

Evaluation of the spoilage potential of bacteria isolated from chilled chicken in vitro and in situ.

Science.gov (United States)

Wang, Guang-Yu; Wang, Hu-Hu; Han, Yi-Wei; Xing, Tong; Ye, Ke-Ping; Xu, Xing-Lian; Zhou, Guang-Hong

2017-05-01

Microorganisms play an important role in the spoilage of chilled chicken. In this study, a total of 53 isolates, belonging to 7 species of 3 genera, were isolated using a selective medium based on the capacity to spoil chicken juice. Four isolates, namely Aeromonas salmonicida 35, Pseudomonas fluorescens H5, Pseudomonas fragi H8 and Serratia liquefaciens 17, were further characterized to assess their proteolytic activities in vitro using meat protein extracts and to evaluate their spoilage potential in situ. The in vitro studies showed that A. salmonicida 35 displayed the strongest proteolytic activity against both sarcoplasmic and myofibrillar proteins. However, the major spoilage isolate in situ was P. fragi H8, which exhibited a fast growth rate, slime formation and increased pH and total volatile basic nitrogen (TVBN) on chicken breast fillets. The relative amounts of volatile organic compounds (VOCs) originating from the microorganisms, including alcohols, aldehydes, ketones and several sulfur compounds, increased during storage. In sum, this study demonstrated the characteristics of 4 potential spoilage bacteria on chilled yellow-feather chicken and provides a simple and convenient method to assess spoilage bacteria during quality management. Copyright © 2016 Elsevier Ltd. All rights reserved.

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...

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

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.

Shelf life and safety concerns of bakery products--a review.

Science.gov (United States)

Smith, James P; Daifas, Daphne Phillips; El-Khoury, Wassim; Koukoutsis, John; El-Khoury, Anis

2004-01-01

Bakery products are an important part of a balanced diet and, today, a wide variety of such products can be found on supermarket shelves. This includes unsweetened goods (bread, rolls, buns, crumpets, muffins and bagels), sweet goods (pancakes, doughnuts, waffles and cookies) and filled goods (fruit and meat pies, sausage rolls, pastries, sandwiches, cream cakes, pizza and quiche). However, bakery products, like many processed foods, are subject to physical, chemical and microbiological spoilage. While physical and chemical spoilage limits the shelf life of low and intermediate moisture bakery products, microbiological spoilage by bacteria, yeast and molds is the concern in high moisture products i.e., products with a water activity (a(w)) > 0.85. Furthermore, several bakery products also have been implicated infoodborne illnesses involving Salmonella spp., Listeria monoctyogenes and Bacillus cereus, while Clostridium botulinum is a concern in high moisture bakery products packaged under modified atmospheres. This extensive review is divided into two parts. Part I focuses on the spoilage concerns of low, intermediate and high moisture bakery products while Part II focuses on the safety concerns of high moisture bakery products only. In both parts, traditional and novel methods of food preservation that can be used by the bakery industry to extend the shelf life and enhance the safety of products are discussed in detail.

Detection of irradiated foods by the DEFT/APC method

International Nuclear Information System (INIS)

Yuecel, P. K.; Koeseoglu, T.; Halkman, H. B. D.

2009-01-01

Irradiation technology is used to prevent the spoilage losses and to improve the hygienic quality of foods. Appropriate techniques for the detection of irradiated foods are needed to guarantee the proper consumer information and to facilitate the trade of irradiated foods. The characteristics of the microbial population of irradiated foods have been used for developing detection methods for irradiated foods. This microbiological method is based on the comparison of an aerobic plate count (APC) with a count obtained with the direct epifluorescent filter technique (DEFT) for the detection of irradiation of foodstuffs.

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

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

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.

Effects of Food Based Yeast on Oxidant-Antioxidant Systems in Rats fed by High Cholesterol Diet

OpenAIRE

Savaş, Hasan Basri; Yüksel, Özlem; Şanlıdere Aloğlu, Hatice; Öner, Zübeyde; Demir Özer, Ezgi; Gültekin, Fatih

2013-01-01

In living organisms, oxidant and antioxidant systems are in a balance. In the present study, our aim was to study the effects of Cryptococcus humicola, which is a food based yeast whose cholesterol lowering activity is under investigation, on oxidant and antioxidant systems.31 adult male, Wistar albino rats weighing 200-250 gr were included in the study. Rats were divided into four groups based on their diets. Group 1(Control Group) was fed a normal diet, Group 2 was fed a high cholesterol di...

Radiation processing of food products with 5 MV Bremsstrahlung x-rays

International Nuclear Information System (INIS)

Petwal, V.C.; Soni, H.C.

2004-01-01

Foods and agricultural products are treated with ionizing radiation to accomplish many different goals. The desired goals may be the reduction of pathogenic bacteria, other microorganisms and parasites that cause food borne diseases; or inactivation of food spoilage organisms, including bacteria, molds, and yeasts; or lengthening the shelf-life of fresh fruits and vegetables by decreasing the normal biological changes associated with growth and maturation processes, such as ripening or sprouting. It has become more important due to mounting concern over food born diseases, and growing international trade in food products that must meet stiff import standards of quality and quarantine. A 10 MeV 10 kW LINAC based multi-product EB radiation processing facility is being established at CAT to meet the processing requirement of various food, agricultural and medical products. The facility will be operated in two modes: (a) Electron: 10 MeV, 10 kW (b) Photon: 5 MeV, 10 kW Treatment with electron beam provides the highest processing rate and lowest unit cost. But the electrons have relatively short range in the solid product, hence the maximum product areal density (density times depth) that can be processed using direct 10 MeV electron beam is limited to about 8.5 gm/cm 2 (double sided irradiation). On the other hand x-rays are more penetrating, hence can be used to process the products having larger areal densities e.g. onions and potatoes packed in gunny bags. In order to address various issues related to food irradiation using 5 MV X-ray beam, a mathematical model is developed on the basis of the analytical calculations and experimental data presented by R.B.Miller, 2003, and J. Meissner et.al, 2000. (author)

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

Role of killer factors in the inhibitory activity of bio-control yeasts against Penicillium expansum and Aspergillus ochraceus

Directory of Open Access Journals (Sweden)

Ciro da Silva Portes

2013-08-01

Full Text Available This work evaluated the antagonism of killer positive yeast strains (isolated from 11 samples of different frozen fruit pulps against the strains of Penicillium expansum and Aspergillus ochraceus. Of the total 41 killer yeasts tested in YM agar, 19 showed antibiosis against P. expansum and A. ochraceus, with inhibition zone ranging from 10 to 18 mm and 10 to 19 mm, respectively. In the following step, the extracellular activity of Kluyveromyces sp. FP4(13 was tested performing the assay in YM broth. The antifungal activity of Kluyveromyces sp. FP4(13 cell-free culture supernatant (25ºC/96 h was more effective against the conidia germination, showing inhibition rates of 93.33 and 86.44% for P. expansum and A. ochraceus, respectively. The micelial growth inhibition was 28.45 and 21.0%, respectively. The antagonism showed by the selected yeasts could be used as a promising alternative tool to reduce and control the postharvest fungal spoilage of the fruits. However, further studies should be carried out in order to better elucidate the role of innocuous characters in antagonistic microorganisms, as well as the purification and characterization of new killer toxins.

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.

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)

Yeasts: providing questions and answers for modern biology.

Science.gov (United States)

Dickinson, J R

2000-01-01

Yeasts are to be found in virtually every conceivable niche on this planet and are amazingly varied in their shapes ('morphologies'), life cycles, metabolic capabilities, potentials for use in industrial processes, abilities to spoil food and drink or to act as dangerous human pathogens. This review describes four very different species of yeast to illustrate some of the diversity which exists and, in the case of one of them, Saccharomyces cerevisiae (the familiar baker's or brewer's yeast), the extent of both our knowledge and ignorance.

The Influence of Brewer’s Yeast Autolysate and Lactic Acid Bacteria on the Production of a Functional Food Additive Based on Beetroot Juice Fermentation

Directory of Open Access Journals (Sweden)

Josip Baras

2004-01-01

Full Text Available The importance of »functional foods« in the world is increasing, and the procedures for their production are under intense development. The goal of this paper is to optimise the production of a functional food additive based on beetroot juice (Beta vulgaris L. using brewer’s yeast autolysate. In order to improve the nutritive properties of the product and to preserve it, the possibility of beetroot juice fermentation using a Lactobacillus species has been investigated. Comparative investigations of three bacteria cultures (L. plantarum A112, L. acidophilus BGSJ15-3 and L. acidophilus NCDO1748 during fermentation in two media, beetroot juice and a mixture of beetroot juice with an autolysate of brewer´s yeast, have been performed. The poorest fermentative activity and growth in both substrates was observed using the L. acidophilus NCDO1748 culture. The two cultures demonstrated better fermentative activity in the mixture of tested substrates, while acidifying activity (production of lactic acid and a decrease in pH of the L. acidophilus BGSJ15-3 culture was considerably better than that of the L. plantarum A112 culture. L. plantarum A112 culture showed better growth than L. acidophilus BGSJ15-3. From the results obtained, it has been concluded that the L. plantarum A112 and L. acidophilus BGSJ15-3 can be successfully used for fermentation of the mixture of beetroot juice and brewer’s yeast autolysate in order to obtain a functional food additive.

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.

Antimicrobial and probiotic properties of yeast: from fundamental to novel applications

Directory of Open Access Journals (Sweden)

Hatoum eRima

2012-12-01

Full Text Available The yeasts constitute a large and heterogeneous group of microorganisms that are currently attracting increased attention from scientists and industry. Numerous and diverse biological activities make them promising candidates for a wide range of applications not limited to the food sector. In addition to their major contribution to flavor development in fermented foods, their antagonistic activities toward undesirable bacteria and fungi are now widely known. These activities are associated with their competitiveness for nutrients, acidification of their growth medium, their tolerance of high concentrations of ethanol, and release of antimicrobial compounds such as antifungal killer toxins or mycocins and antibacterial compounds. While the design of foods containing probiotics (microorganisms that confer health benefits has focused primarily on Lactobacillus and Bifidobacterium, the yeast Saccharomyces cerevisiae var. boulardii has long been known effective for treating gastroenteritis. In this review, the antimicrobial activities of yeasts are examined. Mechanisms underlying this antagonistic activity as well as recent applications of these biologically active yeasts in both the medical and veterinary sectors are described.

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

Transcriptomic analysis on the formation of the viable putative non-culturable state of beer-spoilage Lactobacillus acetotolerans.

Science.gov (United States)

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

2016-11-07

Lactic acid bacteria (LAB) are the most common beer-spoilage bacteria regardless of beer type, and thus pose significant problems for the brewery industry. The aim of this study was to investigate the genetic mechanisms involved in the ability of the hard-to-culture beer-spoilage bacterium Lactobacillus acetotolerans to enter into the viable putative non-culturable (VPNC) state. A genome-wide transcriptional analysis of beer-spoilage L. acetotolerans strains BM-LA14526, BM-LA14527, and BM-LA14528 under normal, mid-term and VPNC states were performed using RNA-sequencing (RNA-seq) and further bioinformatics analyses. GO function, COG category, and KEGG pathway enrichment analysis were conducted to investigate functional and related metabolic pathways of the differentially expressed genes. Functional and pathway enrichment analysis indicated that heightened stress response and reduction in genes associated with transport, metabolic process, and enzyme activity might play important roles in the formation of the VPNC state. This is the first transcriptomic analysis on the formation of the VPNC state of beer spoilage L. acetotolerans.

Evaluation of the antimicrobial activity of pecan nut [Carya illinoinensis (Wangenh C. Koch] shell aqueous extract on minimally processed lettuce leaves

Directory of Open Access Journals (Sweden)

Sabrina CAXAMBÚ

2016-01-01

Full Text Available Abstract Pecan nutshell is a residue from food industry that has potential to be used as biopreservative in foods. The objective of this study was to evaluate the antimicrobial activity of pecan nutshell aqueous extract in vitro and its effectiveness to inhibit spoilage microorganisms on lettuce leaves. The results indicate that the aqueous extract presents inhibitory activity against important foodborne pathogenic bacteria such as Listeria monocytogenes, Salmonella Enteritidis, Staphylococcus aureus, Bacillus cereus, Aeromonas hydrophila and Pseudomonas aeruginosa. Antimicrobial activity was not observed against Corynebacterium fimi, Clostridium perfringens, Escherichia coli, and the phytopathogenic fungi tested. When applied onto lettuce leaves, pecan nutshell extract reduced the counts of mesophilic and psychrotrophic bacteria in 2 and 4 log CFU/g, respectively, during storage of leafy for 5 days at refrigeration temperature (5 °C. The extract was not effective to inhibit yeast on lettuce leaves. Thus, the aqueous extract of pecan shell showed great potential to be used as a natural preservative in foods, acting mainly in the inhibition of spoilage and pathogenic bacteria.

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.)

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

Vegemite Beer: yeast extract spreads as nutrient supplements to promote fermentation

Directory of Open Access Journals (Sweden)

Edward D. Kerr

2016-08-01

Full Text Available Vegemite is an iconic Australian food spread made from spent brewers’ yeast extract, which has been reported to be used as an ingredient in illegal home brewing. In this study, we tested the utility of Vegemite and the similar spread Marmite in promoting fermentation. We could not culture microorganisms from either Vegemite or Marmite, consistent with these food-grade spreads being essentially sterile. To test if the addition of Vegemite or Marmite could assist in fermentation when additional viable yeast was also present, solutions containing glucose and a range of concentrations of either Vegemite or Marmite were inoculated with brewers’ yeast. No fermentation occurred in any condition without addition of extra brewer’s yeast. Fermentation did not occur when yeast was inoculated into solutions containing only glucose, but progressed efficiently with when Vegemite or Marmite was also added. Gas Chromatography confirmed that ethanol was present at ∼3% v/v post-fermentation in all samples which contained glucose, Vegemite or Marmite, and brewers’ yeast. Trace amounts of methanol were also detected. Mass spectrometry proteomics identified abundant intracellular yeast proteins and barley proteins in Vegemite and Marmite, and abundant secreted yeast proteins from actively growing yeast in those samples to which extra brewers’ yeast had been added. We estimate that the real-world cost of home brewed “Vegemite Beer” would be very low. Our results show that Vegemite or other yeast extract spreads could provide cheap and readily available sources of nutrient supplementation to increase the efficiency of fermentation in home brewing or other settings.

Bread, beer and wine: yeast domestication in the Saccharomyces sensu stricto complex.

Science.gov (United States)

Sicard, Delphine; Legras, Jean-Luc

2011-03-01

Yeasts of the Saccharomyces sensu stricto species complex are able to convert sugar into ethanol and CO(2) via fermentation. They have been used for thousands years by mankind for fermenting food and beverages. In the Neolithic times, fermentations were probably initiated by naturally occurring yeasts, and it is unknown when humans started to consciously add selected yeast to make beer, wine or bread. Interestingly, such human activities gave rise to the creation of new species in the Saccharomyces sensu stricto complex by interspecies hybridization or polyploidization. Within the S. cerevisiae species, they have led to the differentiation of genetically distinct groups according to the food process origin. Although the evolutionary history of wine yeast populations has been well described, the histories of other domesticated yeasts need further investigation. Copyright © 2011 Académie des sciences. Published by Elsevier SAS. All rights reserved.

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)

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.

Yeast biotechnology: teaching the old dog new tricks.

Science.gov (United States)

Mattanovich, Diethard; Sauer, Michael; Gasser, Brigitte

2014-03-06

Yeasts are regarded as the first microorganisms used by humans to process food and alcoholic beverages. The technology developed out of these ancient processes has been the basis for modern industrial biotechnology. Yeast biotechnology has gained great interest again in the last decades. Joining the potentials of genomics, metabolic engineering, systems and synthetic biology enables the production of numerous valuable products of primary and secondary metabolism, technical enzymes and biopharmaceutical proteins. An overview of emerging and established substrates and products of yeast biotechnology is provided and discussed in the light of the recent literature.

Psychological aspects of food safety risk perception

DEFF Research Database (Denmark)

Scholderer, Joachim

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...... problematic food safety behaviours are likely to occur. The presentation will begin with an overview of the relevant psychological mechanisms that regulate approach and avoidance behaviour with respect to potentially hazardous foods. Learned representations of familiarity and reward value act as safety...

Functional food red yeast rice (RYR) for metabolic syndrome amelioration: a review on pros and cons.

Science.gov (United States)

Patel, Seema

2016-05-01

Red yeast rice (RYR), the fermentation product of mold Monascus purpureus has been an integral part of Oriental food and traditional Chinese medicine, long before the discovery of their medicinal roles. With the identification of bioactive components as polyketide pigments (statins), and unsaturated fatty acids, RYR has gained a nutraceutical status. Hypercholesterolemic effect of this fermented compound has been validated and monacolin K has been recognized as the pivotal component in cholesterol alleviation. Functional similarity with commercial drug lovastatin sans the side effects has catapulted its popularity in other parts of the world as well. Apart from the hypotensive role, ameliorative benefits of RYR as anti-inflammatory, antidiabetic, anticancer and osteogenic agent have emerged, fueling intense research on it. Mechanistic studies have revealed their interaction with functional agents like coenzyme Q10, astaxanthin, vitamin D, folic acid, policosanol, and berberine. On the other hand, concurrence of mycotoxin citrinin and variable content of statin has marred its integration in mainstream medication. In this disputable scenario, evaluation of the scopes and lacunae to overcome seems to contribute to an eminent area of healthcare. Red yeast rice (RYR), the rice-based fermentation product of mold Monascus purpureus is a functional food. Its bioactive component monacolin K acts like synthetic drug lovastatin, without the severe side effects of the latter. RYR has been validated to lower cholesterol, control high blood pressure; confer anti-flammation, hypoglycaemic, anticancer and osteogenic properties. However, dose inconsistency and co-occurrence of toxin citrinin hampers its dietary supplementation prospect. Further research might facilitate development of RYR as a nutraceutical.

Evaluation of the Hydrophobic Grid Membrane Filter for the Enumeration of Moulds and Yeasts in Naturally-Contaminated Foods

Directory of Open Access Journals (Sweden)

V.H. Tournas

2009-01-01

Full Text Available Over 240 food samples from six food groups (tree nuts, grains and grain products, dried fruits, fresh produce, fruit juice, and dairy products were tested for levels of fungal contamination using the NEO-GRID hydrophobic grid membrane filter (HGMF and the FDA official (BAM method. Results showed that HGMF performed very well for all tested commodities giving yeast and mould (YM counts similar to those of the BAM (reference method. Statistical analysis of the data (t-test revealed no significant differences between the two methods for all foods tested. Regression analysis showed that there was a good fit linear relationship between the two methods for most of the commodities examined. Some difficulties were encountered during counting of the colonies on HGMF since the size of the grid is very small and the number of possible colonies per plate can reach 1600.

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.

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)

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

Essential Oil of Common Thyme as a Natural Antimicrobial Food Additive

Directory of Open Access Journals (Sweden)

Jasna Dolenc Koce

2014-01-01

Full Text Available Antimicrobial activities of thyme essential oil against selected microorganisms, including Fusarium sp., Armillaria mellea, Bacillus cereus, Staphylococcus aureus, Buttiauxella sp., Klebsiella pneumoniae, Escherichia coli K-12, AmpC-producing E. coli Z, ESBL-producing E. coli strain of KM clonal group ST131, and E. coli 1138 were evaluated. The antimicrobial efficacy of thyme essential oil was determined using agar well diffusion assays. The growth of all tested bacteria was inhibited at thyme essential oil fractions higher than 1 %, while a fraction of 10 % was needed to inhibit the growth of fungi. We demonstrate that thyme essential oil has a promising activity against food spoilage bacteria, and also against multiresistant AmpC-producing and ESBL-producing bacterial strains isolated from food, which have recently been recognised as public health concerns. On the basis of our data, the thyme essential oil has a potential for use as a growth inhibitor of multidrug-resistant bacteria, and food spoilage and pathogenic bacteria and fungi, to replace commonly used semi-synthetic antimicrobial products.

Brewer?s Yeast Improves Blood Pressure in Type 2 Diabetes Mellitus

OpenAIRE

HOSSEINZADEH, Payam; DJAZAYERY, Abolghassem; MOSTAFAVI, Seyed-Ali; JAVANBAKHT, Mohammad Hassan; DERAKHSHANIAN, Hoda; RAHIMIFOROUSHANI, Abbas; DJALALI, Mahmoud

2013-01-01

Background This study was conducted to investigate the effects of Brewer?s yeast supplementation on serum lipoproteins and blood pressure in patients with Type 2 diabetes mellitus. Methods: In a randomized double blind clinical trial, 90 adults with type 2 diabetes mellitus were recruited, and divided randomly into 2 groups, trial group received brewer?s yeast (1800 mg/day) and control group received placebo for 12 weeks. Weight, BMI, food consumption (based on 24 hour food recall), fasting s...

Carnobacterium: positive and negative effects in the environment and in foods

DEFF Research Database (Denmark)

Leisner, J.J.; Laursen, B.G.; Prevost, H.

2007-01-01

variation. The responsible spoilage metabolites are not well characterized, but branched alcohols and aldehydes play a partial role. Their production of tyramine in foods is critical for susceptible individuals, but carnobacteria are not otherwise human pathogens. Carnobacterium maltaromaticum can be a fish...

Sheep milk yogurt from a short food supply chain: study of the microbiological, chemico-physical and organoleptic parameters in relation to shelf-life

Directory of Open Access Journals (Sweden)

Nicla Marri

2014-08-01

Full Text Available Aim of this work was to analyse some microbiological, chemico-physical and organoleptic parameters of sheep milk yogurt during and after its declared shelf-life. Five samples of a sheep’s milk yogurt of the same lot, collected from a short supply chain ovine dairy farm of the Roman province, were analysed. Declared shelf-life of the product was 30 days. The products were examined at 2, 14, 30, 35 and 40 days from the production date, performing the following microbiological analyses: enumeration of i colony-forming units characteristic of the yogurt, ii Enterobacteriaceae, iii yeasts and/or moulds at 25°C. Microbiological identification was performed by miniature biochemical tests and for the lactic acid bacteria also by PCR. At every test interval, evaluation of organoleptic parameters and pH was also performed. The analysed product maintained an almost constant amount of lactic acid bacteria until the end of the declared shelf-life. Concerning lactic acid bacteria, a 100% concordance of the results observed by using biochemical identification methods and PCR assays was obtained. After 14 days from the production, the presence of yeasts (Candida famata was revealed, while the presence of moulds was detected after 30 days. Ralstonia picketii, an environmental microorganism, was also isolated. The results obtained in this study indicate that yogurt spoilage is mainly due to the growth of specific microorganisms of spoilage, such as yeasts and moulds.

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

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 ...

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.

Yeast biotechnology: teaching the old dog new tricks

Science.gov (United States)

2014-01-01

Yeasts are regarded as the first microorganisms used by humans to process food and alcoholic beverages. The technology developed out of these ancient processes has been the basis for modern industrial biotechnology. Yeast biotechnology has gained great interest again in the last decades. Joining the potentials of genomics, metabolic engineering, systems and synthetic biology enables the production of numerous valuable products of primary and secondary metabolism, technical enzymes and biopharmaceutical proteins. An overview of emerging and established substrates and products of yeast biotechnology is provided and discussed in the light of the recent literature. PMID:24602262

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

Novel natural food antimicrobials.

Science.gov (United States)

Juneja, Vijay K; Dwivedi, Hari P; Yan, Xianghe

2012-01-01

Naturally occurring antimicrobial compounds could be applied as food preservatives to protect food quality and extend the shelf life of foods and beverages. These compounds are naturally produced and isolated from various sources, including plants, animals and microorganisms, in which they constitute part of host defense systems. Many naturally occurring compounds, such as nisin, plant essential oils, and natamycin, have been widely studied and are reported to be effective in their potential role as antimicrobial agents against spoilage and pathogenic microorganisms. Although some of these natural antimicrobials are commercially available and applied in food processing, their efficacy, consumer acceptance and regulation are not well defined. This manuscript reviews natural antimicrobial compounds with reference to their applications in food when applied individually or in combination with other hurdles. It also reviews the mechanism of action of selected natural antimicrobials, factors affecting their antimicrobial activities, and future prospects for use of natural antimicrobials in the food industry.

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.

Live Yeast and Yeast Cell Wall Supplements Enhance Immune Function and Performance in Food-Producing Livestock: A Review †,‡

Directory of Open Access Journals (Sweden)

Paul R. Broadway

2015-08-01

Full Text Available More livestock producers are seeking natural alternatives to antibiotics and antimicrobials, and searching for supplements to enhance growth performance, and general animal health and well-being. Some of the compounds currently being utilized and studied are live yeast and yeast-based products derived from the strain Saccharomyces cerevisiae. These products have been reported to have positive effects both directly and indirectly on the immune system and its subsequent biomarkers, thereby mitigating negative effects associated with stress and disease. These yeast-based products have also been reported to simultaneously enhance growth and performance by enhancing dry matter intake (DMI and average daily gain (ADG perhaps through the establishment of a healthy gastrointestinal tract. These products may be especially useful in times of potential stress such as during birth, weaning, early lactation, and during the receiving period at the feedlot. Overall, yeast supplements appear to possess the ability to improve animal health and metabolism while decreasing morbidity, thereby enhancing profitability of these animals.

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

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

Nanostructures for delivery of natural antimicrobials in food.

Science.gov (United States)

Lopes, Nathalie Almeida; Brandelli, Adriano

2017-04-10

Natural antimicrobial compounds are a topic of utmost interest in food science due to the increased demand for safe and high-quality foods with minimal processing. The use of nanostructures is an interesting alternative to protect and delivery antimicrobials in food, also providing controlled release of natural compounds such as bacteriocins and antimicrobial proteins, and also for delivery of plant derived antimicrobials. A diversity of nanostructures are capable of trapping natural antimicrobials maintaining the stability of substances that are frequently sensitive to food processing and storage conditions. This article provides an overview on natural antimicrobials incorporated in nanostructures, showing an effective antimicrobial activity on a diversity of food spoilage and pathogenic microorganisms.

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.)

Effect of electron-ion treatment on fermentative activity of food yeasts

International Nuclear Information System (INIS)

Sergeev, I.N.; Ostapenkov, A.M.

1988-01-01

Investigation into effect of electron-ion treatment (EIT) on fermentative activity (FA) of Sacch cerevisial type yeasts of 12 breed was conducted. It is shown that even within the limits of one and the same type different treatment regimes are meded. This is obviously connected with physiologic peculiarities of different yeast breeds. Therefore an individual optimal treatment regime should be determined in each particular case during EIT of different breeds

The Effect of High Hydrostatic Pressure on Microorganisms in Food Preservation

OpenAIRE

M. Arici

2006-01-01

High hydrostatic pressure is a new food preservation technology known for its capacity to inactivate spoilage and pathogenic microorganisms. High-pressure treatments are receiving a great deal of attention for the inactivation of microorganisms in food processing, pressure instead of temperature is used as stabilizing factor. High hydrostatic pressure treatment is the most studied alternative process, many works reported successful results in inactivating a wide range of microorganisms under ...

Combination of antagonistic yeasts with two food additives for control of brown rot caused by Monilinia fructicola on sweet cherry fruit.

Science.gov (United States)

Qin, G Z; Tian, S P; Xu, Y; Chan, Z L; Li, B Q

2006-03-01

To evaluate beneficial effect of two food additives, ammonium molybdate (NH4-Mo) and sodium bicarbonate (NaBi), on antagonistic yeasts for control of brown rot caused by Monilinia fructicola in sweet cherry fruit under various storage conditions. The mechanisms of action by which food additives enhance the efficacy of antagonistic yeasts were also evaluated. Biocontrol activity of Pichia membranefaciens and Cryptococcus laurentii against brown rot in sweet cherry fruit was improved by addition of 5 mmol l(-1) NH4-Mo or 2% NaBi when stored in air at 20 and 0 degrees C, and in controlled atmosphere (CA) storage with 10% O2 + 10% CO2 at 0 degrees C. Population dynamics of P. membranefaciens in the wounds of fruit were inhibited by NH4-Mo at 20 degrees C after 1 day of incubation and growth of C. laurentii was inhibited by NH4-Mo at 0 degrees C in CA storage after 60 days. In contrast, NaBi did not significantly influence growth of the two yeasts in fruit wounds under various storage conditions except that the growth of P. membranefaciens was stimulated after storage for 45 days at 0 degrees C in CA storage. When used alone, the two additives showed effective control of brown rot in sweet cherry fruit and the efficacy was closely correlated with the concentrations used. The result of in vitro indicated that growth of M. fructicola was significantly inhibited by NH4-Mo and NaBi. Application of additives improved biocontrol of brown rot on sweet cherry fruit under various storage conditions. It is postulated that the enhancement of disease control is directly because of the inhibitory effects of additives on pathogen growth, and indirectly because of the relatively little influence of additives on the growth of antagonistic yeasts. The results obtained in this study suggest that an integration of NH4-Mo or NaBi with biocontrol agents has great potential in commercial management of postharvest diseases of fruit.

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

, from spoiled products and by using a specific detection method. The data were analysed using the similarity coefficient and the unweighted pair-group with arithmetic averages algorithm. In addition twenty-six of the fish isolates and five reference strains were analysed by Curie-point pyrolysis mass...... 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......Forty strains of luminous and non-luminous Photobacterium phosphoreum isolates from cod (Gadus morhua) and seven reference strains of psychrotolerant and mesophilic photobacteria were examined for 156 unit characters in a numerical taxonomic study. The fish strains were isolated from the intestines...

Combination Processes in Food Irradiation. Proceedings of an International Symposium on Combination Processes in Food Irradiation

International Nuclear Information System (INIS)

1981-01-01

Statistics show that over forty per cent of the human population, a large portion of which come from the Third World, are suffering from hunger and malnutrition. While the solution to these problems depends to a great extent on the food production strategies of the various governments, equally important is the need to preserve existing food supply by reducing food and crop spoilage. It has been reported that estimated losses due to bacterial spoilage are heavy; those of highly perishable commodities such as fish and fishery products have been reported as amounting to thirty per cent of the total catch. An additional loss of five to ten per cent due to insects and microbes during lengthy periods of drying and/or storage has also been reported. After about thirty years of research, treatment with ionizing radiations has been proved to be a valuable potential tool for reducing post-harvest storage losses and for preserving quickly perishable food from deterioration. Since irradiation is a purely physical method of food conservation, it may for many purposes become the preferred method, for it is an environmentally clean process not tainted with the chemical residue problem, it is energy saving, and it can, in many cases, produce effects that cannot be achieved by conventional techniques (e.g. decontamination of frozen food without significant temperature changes, disinfestation and decontamination of food in bulk and packaged). The preservative effects of ionizing radiations can often be advantageously combined with effects of other physical or chemical agents. The resulting ''combination treatments'' may involve synergistic or cumulative action of the combination partners, leading to a decreased treatment requirement for one or both agents. This in turn may result in cost and/or energy savings and may bring about improvements in the sensory properties and bacteriological quality of the food thus treated. To review progress in this field a Symposium on Combination

Combination Processes in Food Irradiation. Proceedings of an International Symposium on Combination Processes in Food Irradiation

Energy Technology Data Exchange (ETDEWEB)

NONE

1981-09-15

Statistics show that over forty per cent of the human population, a large portion of which come from the Third World, are suffering from hunger and malnutrition. While the solution to these problems depends to a great extent on the food production strategies of the various governments, equally important is the need to preserve existing food supply by reducing food and crop spoilage. It has been reported that estimated losses due to bacterial spoilage are heavy; those of highly perishable commodities such as fish and fishery products have been reported as amounting to thirty per cent of the total catch. An additional loss of five to ten per cent due to insects and microbes during lengthy periods of drying and/or storage has also been reported. After about thirty years of research, treatment with ionizing radiations has been proved to be a valuable potential tool for reducing post-harvest storage losses and for preserving quickly perishable food from deterioration. Since irradiation is a purely physical method of food conservation, it may for many purposes become the preferred method, for it is an environmentally clean process not tainted with the chemical residue problem, it is energy saving, and it can, in many cases, produce effects that cannot be achieved by conventional techniques (e.g. decontamination of frozen food without significant temperature changes, disinfestation and decontamination of food in bulk and packaged). The preservative effects of ionizing radiations can often be advantageously combined with effects of other physical or chemical agents. The resulting ''combination treatments'' may involve synergistic or cumulative action of the combination partners, leading to a decreased treatment requirement for one or both agents. This in turn may result in cost and/or energy savings and may bring about improvements in the sensory properties and bacteriological quality of the food thus treated. To review progress in this field a Symposium on Combination

Assessment of environmental impact of commercial wine yeast in vineyard ecosystems

OpenAIRE

Valero, Eva; Schuller, Dorit Elisabeth; Cambon, Brigitte; Casal, Margarida; Dequin, Sylvie

2005-01-01

Poster e resumo apresentados no congresso "Intrafood 2005 - Innovations in traditional foods", em Valencia, Espanha, em 2005. Modern winemaking practices and diversification of wine products involve an increasing quest for specialised wine yeasts. During the last two decades considerable efforts have been made to improve wine yeast strains through the use of new biotechnologies. In the present study we used commercial wine yeast currently used in wineries as a model to assess the potential...

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

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...

Biogas Production from Brewer’s Yeast Using an Anaerobic Sequencing Batch Reactor

OpenAIRE

Zupančič, Gregor Drago; Panjičko, Mario; Zelić, Bruno

2017-01-01

Renewable energy sources are becoming increasingly important in the beverage and food industries. In the brewing industry, a significant percentage of the used raw materials finishes the process as secondary resource or waste. The research on the anaerobic digestion of brewer’s yeast has been scarce until recent years. One of the reasons for this is its use as a secondary resource in the food industry and as cattle feed. Additionally, market value of brewer’s yeast is higher than its energy v...

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

Energy Technology Data Exchange (ETDEWEB)

Morrison, R. M. [Economic Research Service, USDA (United States)

1986-02-15

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.

Plant-based Paste Fermented by Lactic Acid Bacteria and Yeast: Functional Analysis and Possibility of Application to Functional Foods

Directory of Open Access Journals (Sweden)

Shinsuke Kuwaki

2012-01-01

Full Text Available A plant-based paste fermented by lactic acid bacteria and yeast (fermented paste was made from various plant materials. The paste was made of fermented food by applying traditional food-preservation techniques, that is, fermentation and sugaring. The fermented paste contained major nutrients (carbohydrates, proteins, and lipids, 18 kinds of amino acids, and vitamins (vitamin A, B 1 B 2 , B 6 , B 12 , E, K, niacin, biotin, pantothenic acid, and folic acid. It contained five kinds of organic acids, and a large amount of dietary fiber and plant phytochemicals. Sucrose from brown sugar, used as a material, was completely resolved into glucose and fructose. Some physiological functions of the fermented paste were examined in vitro. It was demonstrated that the paste possessed antioxidant, antihypertensive, antibacterial, anti-inflammatory, anti-allergy and anti-tyrosinase activities in vitro. It was thought that the fermented paste would be a helpful functional food with various nutrients to help prevent lifestyle diseases.

Relation between microbiological quality, metabolite production and sensory quality of equilibrium modified atmosphere packaged fresh-cut produce.

Science.gov (United States)

Jacxsens, L; Devlieghere, F; Ragaert, P; Vanneste, E; Debevere, J

2003-06-25

The quality of four types of fresh-cut produce, packaged in consumer-sized packages under an equilibrium modified atmosphere and stored at 7 degrees C, was assessed by establishing the relation between the microbial outgrowth and the corresponding production of nonvolatile compounds and related sensory disorders. In vitro experiments, performed on a lettuce-juice-agar, demonstrated the production of nonvolatile compounds by spoilage causing lactic acid bacteria and Enterobacteriaceae. Pseudomonas fluorescens and yeasts, however, were not able to produce detectable amounts of nonvolatile metabolites. The type of spoilage and quality deterioration in vivo depended on the type of vegetable. Mixed lettuce and chicory endives, leafy tissues, containing naturally low concentrations of sugars, showed a spoilage dominated by Gram-negative microorganisms, which are not producing nonvolatile compounds. Sensory problems were associated with visual properties and the metabolic activity of the plant tissue. Mixed bell peppers and grated celeriac, on the other hand, demonstrated a fast and intense growth of spoilage microorganisms, dominated by lactic acid bacteria and yeasts. This proliferation resulted in detectable levels of organic acids and the rejection by the trained sensory panel was based on the negative perception of the organoleptical properties (off-flavour, odour and taste). The applied microbiological criteria corresponded well with detectable changes in sensory properties and measurable concentrations of nonvolatile compounds, surely in the cases where lactic acid bacteria and yeasts were provoking spoilage. Consequently, the freshness of minimally processed vegetables, sensitive for outgrowth of lactic acid bacteria and yeasts (e.g., carrots, celeriac, bell peppers, mixtures with non-leafy vegetables) can be evaluated via analysis of the produced nonvolatile compounds.

Effect of Some Plant Extracts on the Microbial Spoilage of Cajanus ...

African Journals Online (AJOL)

The effect of ethanolic extracts of seven plant sources on the microbial spoilage of Cajanus cajan extract was investigated. The results showed that the extracts obtained from Aloe vera, bitter leaf, Gultiferae (garcinia or bitter kola), Ocimum gratissimum (scent leaf) and Zingiber officialae (ginger) were effective against ...

Phytase-producing capacity of yeasts isolated from traditional African fermented food products and PHYPk gene expression of Pichia kudriavzevii strains

DEFF Research Database (Denmark)

Greppi, Anna; Krych, Lukasz; Costantini, Antonella

2015-01-01

Phytate is known as a strong chelate of minerals causing their reduced uptake by the human intestine. Ninety-three yeast isolates from traditional African fermented food products, belonging to nine species (Pichia kudriavzevii, Saccharomyces cerevisiae, Clavispora lusitaniae, Kluyveromyces...... marxianus, Millerozyma farinosa, Candida glabrata, Wickerhamomyces anomalus, Hanseniaspora guilliermondii and Debaryomyces nepalensis) were screened for phytase production on solid and liquid media. 95% were able to grow in the presence of phytate as sole phosphate source, P. kudriavzevii being the best...

Application of food irradiation in developing countries

International Nuclear Information System (INIS)

1966-01-01

The panel on the Application of Food Irradiation in Developing Countries was convened in Vienna by the International Atomic Energy Agency (IAEA) in August 1964. The members of this panel examined the problem of food preservation in geographical areas where much food was lost through spoilage, deterioration and insect infestation. It was thought, that radiation treatment should be used to solve these preservation problems. The attendees included 13 experts, four observers from research organizations, and 2 representatives from the Food and Agriculture Organization (FAO) in Rome. The members of the panel examined the use of ionizing radiation to preserve fish, fruits, and vegetables and to inactivate disease producing viruses which are closely associated with animal products. Refs, figs and tabs

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

Application of food irradiation in developing countries

Energy Technology Data Exchange (ETDEWEB)

1966-05-01

The panel on the Application of Food Irradiation in Developing Countries was convened in Vienna by the International Atomic Energy Agency (IAEA) in August 1964. The members of this panel examined the problem of food preservation in geographical areas where much food was lost through spoilage, deterioration and insect infestation. It was thought, that radiation treatment should be used to solve these preservation problems. The attendees included 13 experts, four observers from research organizations, and 2 representatives from the Food and Agriculture Organization (FAO) in Rome. The members of the panel examined the use of ionizing radiation to preserve fish, fruits, and vegetables and to inactivate disease producing viruses which are closely associated with animal products. Refs, figs and tabs.

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

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)

Yeast Identification During Fermentation of Turkish Gemlik Olives.

Science.gov (United States)

Mujdeci, Gamze; Arévalo-Villena, María; Ozbas, Z Yesim; Briones Pérez, Ana

2018-05-01

Naturally fermented black table olives of the Gemlik variety are one of the most consumed fermented products in Turkey. The objective of this work was to identify yeast strains isolated during their natural fermentation by using Restriction Fragments Lengths Polymorphism-Polimerase Chain Reaction (RFLP-PCR) and DNA sequencing methods. The study also focused on determining the effect of regional differences on yeast microflora of naturally fermented Gemlik olives. A total of 47 yeast strains belonging to 12 different species which had been previously isolated from the natural brine of Akhisar and Iznik-Gemlik cv. olives were characterized by molecular methods. Forty-two of the tested strains could be identified by RFLP-PCR to species level. These yeast species were determined as Candida mycetangi, Candida hellenica, Candida membranaefaciens, Candida famata, Candida pelliculosa, Saccharomyces cerevisiae, and Zygosaccharomyces mrakii. Five strains were identified by DNA sequencing. These strains belonged to three different species: Aureobasidium pullulans, Kloeckera apiculate, and Cryptococcus saitoi. The most frequent species were C. famata and C. pelliculosa in both regions. This work studies the yeasts from Turkish table olives which could prove to be of importance to the food industry in that area. On the other hand, it compares identification by molecular and classical biochemical methods and offers an idea about the differences between the ecosystems of Gemlik olives in the Akhisar (AO) and Iznik (IO) regions. The study could be useful in characterizing a very important product and, in this way, could help to promote its marketing. © 2018 Institute of Food Technologists®.

Phytase-active yeasts from grain-based food and beer.

Science.gov (United States)

Nuobariene, L; Hansen, A S; Jespersen, L; Arneborg, N

2011-06-01

To screen yeast strains isolated from grain-based food and beer for phytase activity to identify high phytase-active strains. The screening of phytase-positive strains was carried out at conditions optimal for leavening of bread dough (pH 5·5 and 30°C), in order to identify strains that could be used for the baking industry. Two growth-based tests were used for the initial testing of phytase-active strains. Tested strains belonged to six species: Saccharomyces cerevisiae, Saccharomyces pastorianus, Saccharomyces bayanus, Kazachstania exigua (former name Saccharomyces exiguus), Candida krusei (teleomorph Issachenkia orientalis) and Arxula adeninivorans. On the basis of initial testing results, 14 strains were selected for the further determination of extracellular and intracellular (cytoplasmic and/or cell-wall bound) phytase activities. The most prominent strains for extracellular phytase production were found to be S. pastorianus KVL008 (a lager beer strain), followed by S. cerevisiae KVL015 (an ale beer strain) and C. krusei P2 (isolated from sorghum beer). Intracellular phytase activities were relatively low in all tested strains. Herein, for the first time, beer-related strains of S. pastorianus and S. cerevisiae are reported as phytase-positive strains. The high level of extracellular phytase activity by the strains mentioned previously suggests them to be strains for the production of wholemeal bread with high content of bioavailable minerals. © 2011 The Authors. Journal of Applied Microbiology © 2011 The Society for Applied Microbiology.

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)

40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Yeast Extract Hydrolysate from... PESTICIDE CHEMICAL RESIDUES IN FOOD Exemptions From Tolerances § 180.1246 Yeast Extract Hydrolysate from... exemption from the requirement of a tolerance for residues of the biochemical pesticide Yeast Extract...

Use of non-conventional yeast improves the wine aroma profile of Ribolla Gialla

NARCIS (Netherlands)

Dashko, Sofia; Zhou, Nerve; Tinta, Tinkara; Sivilotti, Paolo; Lemut, Melita Sternad; Trost, Kajetan; Gamero, Amparo; Boekhout, Teun; Butinar, Lorena; Vrhovsek, Urska; Piskur, Jure

Consumer wine preferences are changing rapidly towards exotic flavours and tastes. In this work, we tested five non-conventional yeast strains for their potential to improve Ribolla Gialla wine quality. These strains were previously selected from numerous yeasts interesting as food production

Brewer's Yeast Improves Glycemic Indices in Type 2 Diabetes Mellitus.

Science.gov (United States)

Hosseinzadeh, Payam; Javanbakht, Mohammad Hassan; Mostafavi, Seyed-Ali; Djalali, Mahmoud; Derakhshanian, Hoda; Hajianfar, Hossein; Bahonar, Ahmad; Djazayery, Abolghassem

2013-10-01

Brewer's yeast may have beneficial effects on insulin receptors because of itsglucose tolerance factor in diabetic patients. This study was conducted to investigate the effects of brewer's yeast supplementation on glycemic indices in patients with type 2 diabetes mellitus. In a randomized double-blind controlled clinical trial, 84 adults (21 men and 63 women) aged 46.3 ± 6.1 years old with type 2 diabetes mellitus were recruited and divided randomly into two groups: Supplement group receiving brewer's yeast (six 300mg tablets/day, total 1800 mg) and control group receiving placebo (six 300mg tablets/day) for 12 weeks. Body weight, height, body mass index, food consumption (based on 24h food record), fasting blood sugar (FBS), glycosylated hemoglobin, insulin sensitivity, and insulin resistance were measured before and after the intervention. Data analysis was performed using the Statistical Package for Social Sciences (version 18.0). The changes in FBS, glycosylated hemoglobin, and insulin sensitivity were significantly different between the two groups during the study (respectively P brewer›s yeast besides the usual treatment of diabetes can ameliorate blood glucose variables in type 2 diabetes mellitus.

Food irradiation: an alternative technology

Energy Technology Data Exchange (ETDEWEB)

Loaharanu, P

1986-12-31

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

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

Looking for immunotolerance: a case of allergy to baker's yeast (Saccharomyces cerevisiae).

Science.gov (United States)

Pajno, G B; Passalacqua, G; Salpietro, C; Vita, D; Caminiti, L; Barberio, G

2005-09-01

We describe one case of baker's yeast true allergy in a boy with previously diagnosed mite-allergy and atopic dermatitis. At the age of 6, being atopic dermatitis and rhinitis well controlled by drugs, he began to experience generalized urticaria and asthma after eating pizza and bread, but only fresh from the oven. The diagnostic workup revealed single sensitization to baker's yeast (Saccharomyces cerevisiae), and a severe systemic reaction also occurred during the prick-by-prick procedure. After discussing with parents, no special dietary restriction was suggested but the use of autoinjectable adrenaline and on demand salbutamol. A diary of symptoms was recorded by means of a visual-analog scale. During the subsequent 2 years, the severity of symptoms was progressively reduced, and presently urticaria has disappeared. Only cough persists, invariantly after eating just-baked and yeast-containing foods. If bread, pizza and cakes are ate more than one hour after preparation, no symptom occur at all. Baker's yeast is a common component of everyday diet and it usually acts as an allergen only by the inhalatory route. We speculate that the continuous exposure to saccharomyces in foods may have lead to an immunotolerance with a progressive reduction of symptoms, whereas why the allergens is active only in ready-baked foods remains unexplained.

Biosurfactant-producing yeasts widely inhabit various vegetables and fruits.

Science.gov (United States)

Konishi, Masaaki; Maruoka, Naruyuki; Furuta, Yoshifumi; Morita, Tomotake; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

2014-01-01

The isolation of biosurfactant-producing yeasts from food materials was accomplished. By a combination of a new drop collapse method and thin-layer chromatography, 48 strains were selected as glycolipid biosurfactant producers from 347 strains, which were randomly isolated from various vegetables and fruits. Of the producers, 69% were obtained from vegetables of the Brassica family. Of the 48 producers, 15 strains gave relatively high yields of mannosylerythritol lipids (MELs), and were identified as Pseudozyma yeasts. These strains produced MELs from olive oil at yields ranging from 8.5 to 24.3 g/L. The best yield coefficient reached 0.49 g/g as to the carbon sources added. Accordingly, MEL producers were isolated at high efficiency from various vegetables and fruits, indicating that biosurfactant producers are widely present in foods. The present results should facilitate their application in the food and related industries.

Influence of food matrix on outgrowth heterogeneity of heat damaged Bacillus cereus spores

NARCIS (Netherlands)

Warda, A.K.; Besten, den H.M.W.; Sha, N.; Abee, T.; Nierop Groot, M.N.

2015-01-01

Spoilage of heat treated foods can be caused by the presence of surviving spore-formers. It is virtually impossible to prevent contamination at the primary production level as spores are ubiquitous present in the environment and can contaminate raw products. As a result spore inactivation treatments

Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces

DEFF Research Database (Denmark)

Bagge, Dorthe; Hjelm, M.; Johansen, C.

2001-01-01

Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buf...... from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces...

Novel Biocontrol Methods for Listeria monocytogenes Biofilms in Food Production Facilities.

Science.gov (United States)

Gray, Jessica A; Chandry, P Scott; Kaur, Mandeep; Kocharunchitt, Chawalit; Bowman, John P; Fox, Edward M

2018-01-01

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 methods and their

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

The role of the yeast as probiotic in protection against liver injury

African Journals Online (AJOL)

khairy

cancer treatment (Chen et al., 2009). In this study, we ... animal food. The final yeast amount eaten by each rat/day was 500 mg/kg/day. Animals. Adult male Wistar albino rats, ageing approximately three months ..... collection of inflammatory cells and loss of hepatic tissue structural pattern; (d) treated with only yeast. CV,.

A mixed-species microarray for identification of food spoilage bacilli

NARCIS (Netherlands)

Caspers, M.P.M.; Schuren, F.H.J.; Zuijlen, van 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

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

Purification of leucocin A for use on wieners to inhibit Listeria monocytogenes in the presence of spoilage organisms.

Science.gov (United States)

Balay, Danielle R; Dangeti, Ramana V; Kaur, Kamaljit; McMullen, Lynn M

2017-08-16

The aims of this study were to improve the method for purification of leucocin A to increase yield of peptide and to evaluate the efficacy of leucocin A and an analogue of leucocin A (leucocin N17L) to inhibit the growth of Listeria monocytogenes on wieners in the presence of spoilage organisms. Leucocin A was produced by Leuconostoc gelidum UAL187 and purified with a five-fold increase in yield; leucocin N17L was synthesized replacing asparagine at residue 17 with leucine. Five strains of L. monocytogenes associated with foodborne illness were used to assess bacteriocin efficacy in vitro and in situ. Minimum inhibitory concentrations could not be determined in broth; however, on agar the minimum inhibitory concentrations ranged from 11.7-62.5μM and 62.5->500μM for leucocin A and leucocin N17L, respectively. Leucocin N17L was less effective than the native bacteriocin at controlling the growth of L. monocytogenes. The inactivation profiles of L. monocytogenes in broth in the presence of leucocin A suggested each isolate had different levels of resistance to the bacteriocin as determined by the initial bactericidal effect. The formation of spontaneously resistance subpopulations were also observed for each strain of L. monocytogenes. In situ, wieners were inoculated with the spoilage organisms, Carnobacterium divergens and Brochothrix thermosphacta, followed by surface application of purified leucocin A, and inoculated with a cocktail of L. monocytogenes. Wieners were vacuum packaged and stored at 7°C for 16d. Leucocin A reduced the counts L. monocytogenes on wieners during storage, regardless of the presence of C. divergens. B. thermosphacta was unaffected by the presence of leucocin A on wieners over the duration of storage. This study suggests that leucocin A may be beneficial to industry as a surface application on wieners to help reduce L. monocytogenes counts due to post-processing contamination even in the presence of spoilage organisms. However, further

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.

The ecology of insect-yeast relationships and its relevance to human industry.

Science.gov (United States)

Madden, Anne A; Epps, Mary Jane; Fukami, Tadashi; Irwin, Rebecca E; Sheppard, John; Sorger, D Magdalena; Dunn, Robert R

2018-03-28

Many species of yeast are integral to human society. They produce many of our foods, beverages and industrial chemicals, challenge us as pathogens, and provide models for the study of our own biology. However, few species are regularly studied and much of their ecology remains unclear, hindering the development of knowledge that is needed to improve the relationships between humans and yeasts. There is increasing evidence that insects are an essential component of ascomycetous yeast ecology. We propose a 'dispersal-encounter hypothesis' whereby yeasts are dispersed by insects between ephemeral, spatially disparate sugar resources, and insects, in turn, obtain the benefits of an honest signal from yeasts for the sugar resources. We review the relationship between yeasts and insects through three main examples: social wasps, social bees and beetles, with some additional examples from fruit flies. Ultimately, we suggest that over the next decades, consideration of these ecological and evolutionary relationships between insects and yeasts will allow prediction of where new yeast diversity is most likely to be discovered, particularly yeasts with traits of interest to human industry. © 2018 The Author(s).

Yeast: A new oil producer?

Directory of Open Access Journals (Sweden)

Beopoulos Athanasios

2012-01-01

Full Text Available The increasing demand of plant oils or animal fat for biodiesel and specific lipid derivatives for the oleochemical field (such as lubricants, adhesives or plastics have created price imbalance in both the alimentary and energy field. Moreover, the lack of non-edible oil feedstock has given rise to concerns on land-use practices and on oil production strategies. Recently, much attention has been paid to the exploitation of microbial oils. Most of them present lipid profiles similar in type and composition to plants and could therefore have many advantages as are no competitive with food, have short process cycles and their cultivation is independent of climate factors. Among microorganisms, yeasts seem to be very promising as they can be easily genetically enhanced, are suitable for large-scale fermentation and are devoid of endotoxins. This review will focus on the recent understanding of yeasts lipid metabolism, the succeeding genetic engineering of the lipid pathways and the recent developments on fermentation techniques that pointed out yeasts as promising alternative producers for oil or plastic.

Selection of oleaginous yeasts for fatty acid production.

Science.gov (United States)

Lamers, Dennis; van Biezen, Nick; Martens, Dirk; Peters, Linda; van de Zilver, Eric; Jacobs-van Dreumel, Nicole; Wijffels, René H; Lokman, Christien

2016-05-27

Oleaginous yeast species are an alternative for the production of lipids or triacylglycerides (TAGs). These yeasts are usually non-pathogenic and able to store TAGs ranging from 20 % to 70 % of their cell mass depending on culture conditions. TAGs originating from oleaginous yeasts can be used as the so-called second generation biofuels, which are based on non-food competing "waste carbon sources". In this study the selection of potentially new interesting oleaginous yeast strains is described. Important selection criteria were: a broad maximum temperature and pH range for growth (robustness of the strain), a broad spectrum of carbon sources that can be metabolized (preferably including C-5 sugars), a high total fatty acid content in combination with a low glycogen content and genetic accessibility. Based on these selection criteria, among 24 screened species, Schwanniomyces occidentalis (Debaromyces occidentalis) CBS2864 was selected as a promising strain for the production of high amounts of lipids.

Assessing phagotrophy in the mixotrophic ciliate Paramecium bursaria using GFP-expressing yeast cells.

Science.gov (United States)

Miura, Takashi; Moriya, Hisao; Iwai, Sosuke

2017-07-03

We used cells of the yeast Saccharomyces cerevisiae expressing green fluorescent protein (GFP) as fluorescently labelled prey to assess the phagocytic activities of the mixotrophic ciliate Paramecium bursaria, which harbours symbiotic Chlorella-like algae. Because of different fluorescence spectra of GFP and algal chlorophyll, ingested GFP-expressing yeast cells can be distinguished from endosymbiotic algal cells and directly counted in individual P. bursaria cells using fluorescence microscopy. By using GFP-expressing yeast cells, we found that P. bursaria altered ingestion activities under different physiological conditions, such as different growth phases or the presence/absence of endosymbionts. Use of GFP-expressing yeast cells allowed us to estimate the digestion rates of live prey of the ciliate. In contrast to the ingestion activities, the digestion rate within food vacuoles was not affected by the presence of endosymbionts, consistent with previous findings that food and perialgal vacuoles are spatially and functionally separated in P. bursaria. Thus, GFP-expressing yeast may provide a valuable tool to assess both ingestion and digestion activities of ciliates that feed on eukaryotic organisms. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The ecology of the Drosophila-yeast mutualism in wineries

Science.gov (United States)

2018-01-01

The fruit fly, Drosophila melanogaster, is preferentially found on fermenting fruits. The yeasts that dominate the microbial communities of these substrates are the primary food source for developing D. melanogaster larvae, and adult flies manifest a strong olfactory system-mediated attraction for the volatile compounds produced by these yeasts during fermentation. Although most work on this interaction has focused on the standard laboratory yeast Saccharomyces cerevisiae, a wide variety of other yeasts naturally ferment fallen fruit. Here we address the open question of whether D. melanogaster preferentially associates with distinct yeasts in different, closely-related environments. We characterized the spatial and temporal dynamics of Drosophila-associated fungi in Northern California wineries that use organic grapes and natural fermentation using high-throughput, short-amplicon sequencing. We found that there is nonrandom structure in the fungal communities that are vectored by flies both between and within vineyards. Within wineries, the fungal communities associated with flies in cellars, fermentation tanks, and pomace piles are distinguished by varying abundances of a small number of yeast species. To investigate the origins of this structure, we assayed Drosophila attraction to, oviposition on, larval development in, and longevity when consuming the yeasts that distinguish vineyard microhabitats from each other. We found that wild fly lines did not respond differentially to the yeast species that distinguish winery habitats in habitat specific manner. Instead, this subset of yeast shares traits that make them attractive to and ensure their close association with Drosophila. PMID:29768432

Food selection in larval fruit flies: dynamics and effects on larval development

Science.gov (United States)

Schwarz, Sebastian; Durisko, Zachary; Dukas, Reuven

2014-01-01

Selecting food items and attaining a nutritionally balanced diet is an important challenge for all animals including humans. We aimed to establish fruit fly larvae ( Drosophila melanogaster) as a simple yet powerful model system for examining the mechanisms of specific hunger and diet selection. In two lab experiments with artificial diets, we found that larvae deprived of either sucrose or protein later selectively fed on a diet providing the missing nutrient. When allowed to freely move between two adjacent food patches, larvae surprisingly preferred to settle on one patch containing yeast and ignored the patch providing sucrose. Moreover, when allowed to move freely between three patches, which provided either yeast only, sucrose only or a balanced mixture of yeast and sucrose, the majority of larvae settled on the yeast-plus-sucrose patch and about one third chose to feed on the yeast only food. While protein (yeast) is essential for development, we also quantified larval success on diets with or without sucrose and show that larvae develop faster on diets containing sucrose. Our data suggest that fruit fly larvae can quickly assess major nutrients in food and seek a diet providing a missing nutrient. The larvae, however, probably prefer to quickly dig into a single food substrate for enhanced protection over achieving an optimal diet.

Biofortification of folates in white wheat bread by selection of yeast strain and process.

Science.gov (United States)

Hjortmo, Sofia; Patring, Johan; Jastrebova, Jelena; Andlid, Thomas

2008-09-30

We here demonstrate that folate content in yeast fermented food can be dramatically increased by using a proper (i) yeast strain and (ii) cultivation procedure for the selected strain prior to food fermentation. Folate levels were 3 to 5-fold higher in white wheat bread leavened with a Saccharomyces cerevisiae strain CBS7764, cultured in defined medium and harvested in the respiro-fermentative phase of growth prior to dough preparation (135-139 microg/100 dry matter), compared to white wheat bread leavened with commercial Baker's yeast (27-43 microg/100 g). The commercial Baker's yeast strain had been industrially produced, using a fed-batch process, thereafter compressed and stored in the refrigerator until bakings were initiated. This strategy is an attractive alternative to fortification of bread with synthetically produced folic acid. By using a high folate producing strain cultured a suitable way folate levels obtained were in accordance with folic acid content in fortified cereal products.

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.

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)

Dietary glucose regulates yeast consumption in adult Drosophila males.

Science.gov (United States)

Lebreton, Sébastien; Witzgall, Peter; Olsson, Marie; Becher, Paul G

2014-01-01

The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic regulation in animals. The fruit fly Drosophila melanogaster feeds on yeasts growing on overripe fruit, providing nutrients required for adult survival, reproduction and larval growth. Here, we present data on how the nutritional value of food affects subsequent yeast consumption in Drosophila adult males. After a period of starvation, flies showed intensive yeast consumption. In comparison, flies stopped feeding after having access to a nutritive cornmeal diet. Interestingly, dietary glucose was equally efficient as the complex cornmeal diet. In contrast, flies fed with sucralose, a non-metabolizable sweetener, behaved as if they were starved. The adipokinetic hormone and insulin-like peptides regulate metabolic processes in insects. We did not find any effect of the adipokinetic hormone pathway on this modulation. Instead, the insulin pathway was involved in these changes. Flies lacking the insulin receptor (InR) did not respond to nutrient deprivation by increasing yeast consumption. Together these results show the importance of insulin in the regulation of yeast consumption in response to starvation in adult D. melanogaster males.

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

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...

Evaluation of Yeast Biomass (Candida utilis in a Practical Diet for Rainbow Trout (Oncorhynchus mykiss

Directory of Open Access Journals (Sweden)

J.S. Goddard

1999-01-01

Full Text Available A yeast, Candida utilis, cultured on a substrate derived from a mixture of peat moss and fish processing waste, was substituted for fish meal in a practical diet for rainbow trout, Oncorhynchus mykiss. The formulated diets were isonitrogenous (40% crude protein and isoealoric (gross energy 20 kJ per g dry matter. During a 50-day feeding trial fish tripled in weight, and there were no significant differences in the mean final weights of groups of fish fed diets in which 0%, 25% and 35% of fishmeal had been replaced by yeast biomass. Diets containing yeast were palatable, as determined by food intake, and were highly digestible for protein. Carcass analysis revealed that the fish fed with yeast biomass had slightly higher crude protein and ash contents, and lower lipid levels than those of the control group. Significant reductions were recorded in food conversion efficiency as the yeast content of the diets increased. The results indicate the potential for partial replacement of fish meal (between 25-35% by Candida utilis biomass in feeds formulated for rainbow trout.

Australian wine consumers’ acceptance of and attitudes toward the use of additives in wine and food production

OpenAIRE

Saltman Y; Johnson TE; Wilkinson KL; Bastian SEP

2015-01-01

Yaelle Saltman, Trent E Johnson, Kerry L Wilkinson, Susan EP Bastian Department of Wine and Food, School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, Adelaide, SA, Australia. Abstract: Additives are routinely used in food and wine production to enhance product quality and/or prevent spoilage. Compared with other industries, the wine industry is only permitted to use a limited number of additives. Whereas flavor additives are often used to intensify the aroma and f...

Experimental study on bread yeast cultured in sweet sorghum juice

International Nuclear Information System (INIS)

Wang Jufang; Dong Xicun; Li Wenjian; Xiao Guoqing; Ma Liang; Gao Feng

2008-01-01

As a substitute for food supplies, sweet sorghum juice with high grade has demonstrated out- standing advantage in fermentation. To obtain the optimized fermentation conditions, the growth, the bio- mass of bread yeast cultured in sweet sorghum juice and total residual sugar were investigated in the paper. The fermentation was performed and optimized in a 10-100 1 bio-reactor. The results show that the application of sweet sorghum juice in bread yeast production is very potential. (authors)

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)

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)

1998-12-31

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)

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)

Pathogenic psychrotolerant sporeformers: an emerging challenge for low-temperature storage of minimally processed foods.

Science.gov (United States)

Markland, Sarah M; Farkas, Daniel F; Kniel, Kalmia E; Hoover, Dallas G

2013-05-01

Sporeforming bacteria are a significant problem in the food industry as they are ubiquitous in nature and capable of resisting inactivation by heat and chemical treatments designed to inactivate them. Beyond spoilage issues, psychrotolerant sporeformers are becoming increasingly recognized as a potential hazard given the ever-expanding demand for refrigerated processed foods with extended shelf-life. In these products, the sporeforming pathogens of concern are Bacillus cereus, Bacillus weihenstephanensis, and Clostridium botulinum type E. This review article examines the foods, conditions, and organisms responsible for the food safety issue caused by the germination and outgrowth of psychrotolerant sporeforming pathogens in minimally processed refrigerated foods.

Biogas Production from Brewer’s Yeast Using an Anaerobic Sequencing Batch Reactor

Directory of Open Access Journals (Sweden)

Gregor Drago Zupančič

2017-01-01

Full Text Available Renewable energy sources are becoming increasingly important in the beverage and food industries. In the brewing industry, a significant percentage of the used raw materials finishes the process as secondary resource or waste. The research on the anaerobic digestion of brewer’s yeast has been scarce until recent years. One of the reasons for this is its use as a secondary resource in the food industry and as cattle feed. Additionally, market value of brewer’s yeast is higher than its energy value. Due to the increase of energy prices, brewer’s yeast has become of interest as energy substrate despite its difficult degradability in anaerobic conditions. The anaerobic co-digestion of brewer’s yeast and anaerobically treated brewery wastewater was studied using a pilot-scale anaerobic sequencing batch reactor (ASBR seeded with granular biomass. The experiments showed very good and stable operation with an organic loading rate of up to 8.0 kg/(m3·day, and with a maximum achieved organic loading rate of 13.6 kg/(m3·day in a single cycle. A specific biogas productivity of over 0.430 m3/kg of the total chemical oxygen demand (COD inserted, and total COD removal efficiencies of over 90 % were achieved. This study suggests that the brewer’s yeast can be successfully digested in an ASBR without adverse effects on the biogas production from brewer’s yeast/wastewater mixtures of up to 8 % (by volume. By using the brewer’s yeast in the ASBR process, the biogas production from brewery wastewater could be increased by 50 %.

Yeast Biomass Production in Brewery's Spent Grains Hemicellulosic Hydrolyzate

Science.gov (United States)

Duarte, Luís C.; Carvalheiro, Florbela; Lopes, Sónia; Neves, Ines; Gírio, Francisco M.

Yeast single-cell protein and yeast extract, in particular, are two products which have many feed, food, pharmaceutical, and biotechnological applications. However, many of these applications are limited by their market price. Specifically, the yeast extract requirements for culture media are one of the major technical hurdles to be overcome for the development of low-cost fermentation routes for several top value chemicals in a biorefinery framework. A potential biotechnical solution is the production of yeast biomass from the hemicellulosic fraction stream. The growth of three pentose-assimilating yeast cell factories, Debaryomyces hansenii, Kluyveromyces marxianus, and Pichia stipitis was compared using non-detoxified brewery's spent grains hemicellulosic hydrolyzate supplemented with mineral nutrients. The yeasts exhibited different specific growth rates, biomass productivities, and yields being D. hansenii as the yeast species that presented the best performance, assimilating all sugars and noteworthy consuming most of the hydrolyzate inhibitors. Under optimized conditions, D. hansenii displayed a maximum specific growth rate, biomass yield, and productivity of 0.34 h-1, 0.61 g g-1, and 0.56 g 1-1 h-1, respectively. The nutritional profile of D. hansenii was thoroughly evaluated, and it compares favorably to others reported in literature. It contains considerable amounts of some essential amino acids and a high ratio of unsaturated over saturated fatty acids.

A vaccine grade of yeast Saccharomyces cerevisiae expressing mammalian myostatin

Directory of Open Access Journals (Sweden)

Zhang Tingting

2012-12-01

Full Text Available Abstract Background Yeast Saccharomyces cerevisiae is a widely-used system for protein expression. We previously showed that heat-killed whole recombinant yeast vaccine expressing mammalian myostatin can modulate myostatin function in mice, resulting in increase of body weight and muscle composition in these animals. Foreign DNA introduced into yeast cells can be lost soon unless cells are continuously cultured in selection media, which usually contain antibiotics. For cost and safety concerns, it is essential to optimize conditions to produce quality food and pharmaceutical products. Results We developed a simple but effective method to engineer a yeast strain stably expressing mammalian myostatin. This method utilized high-copy-number integration of myostatin gene into the ribosomal DNA of Saccharomyces cerevisiae. In the final step, antibiotic selection marker was removed using the Cre-LoxP system to minimize any possible side-effects for animals. The resulting yeast strain can be maintained in rich culture media and stably express mammalian myostatin for two years. Oral administration of the recombinant yeast was able to induce immune response to myostatin and modulated the body weight of mice. Conclusions Establishment of such yeast strain is a step further toward transformation of yeast cells into edible vaccine to improve meat production in farm animals and treat human muscle-wasting diseases in the future.

Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread

Science.gov (United States)

Rezaei, Mohammad Naser; Steensels, Jan; Courtin, Christophe M.; Verstrepen, Kevin J.

2016-01-01

Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today’s diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria. PMID:27776154

Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread.

Science.gov (United States)

Aslankoohi, Elham; Herrera-Malaver, Beatriz; Rezaei, Mohammad Naser; Steensels, Jan; Courtin, Christophe M; Verstrepen, Kevin J

2016-01-01

Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today's diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria.

Non-Conventional Yeast Strains Increase the Aroma Complexity of Bread.

Directory of Open Access Journals (Sweden)

Elham Aslankoohi

Full Text Available Saccharomyces cerevisiae is routinely used yeast in food fermentations because it combines several key traits, including fermentation efficiency and production of desirable flavors. However, the dominance of S. cerevisiae in industrial fermentations limits the diversity in the aroma profiles of the end products. Hence, there is a growing interest in non-conventional yeast strains that can help generate the diversity and complexity desired in today's diversified and consumer-driven markets. Here, we selected a set of non-conventional yeast strains to examine their potential for bread fermentation. Here, we tested ten non-conventional yeasts for bread fermentation, including two Saccharomyces species that are not currently used in bread making and 8 non-Saccharomyces strains. The results show that Torulaspora delbrueckii and Saccharomyces bayanus combine satisfactory dough fermentation with an interesting flavor profile. Sensory analysis and HS-SPME-GC-MS analysis confirmed that these strains produce aroma profiles that are very different from that produced by a commercial bakery strain. Moreover, bread produced with these yeasts was preferred by a majority of a trained sensory panel. These results demonstrate the potential of T. delbrueckii and S. bayanus as alternative yeasts for bread dough leavening, and provide a general experimental framework for the evaluation of more yeasts and bacteria.

Adding Flavor to Beverages with Non-Conventional Yeasts

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Davide Ravasio

2018-02-01

Full Text Available Fungi produce a variety of volatile organic compounds (VOCs during their primary and secondary metabolism. In the beverage industry, these volatiles contribute to the the flavor and aroma profile of the final products. We evaluated the fermentation ability and aroma profiles of non-conventional yeasts that have been associated with various food sources. A total of 60 strains were analyzed with regard to their fermentation and flavor profile. Species belonging to the genera Candida, Pichia and Wickerhamomyces separated best from lager yeast strains according to a principal component analysis taking alcohol and ester production into account. The speed of fermentation and sugar utilization were analysed for these strains. Volatile aroma-compound formation was assayed via gas chromatography. Several strains produced substantially higher amounts of aroma alcohols and esters compared to the lager yeast strain Weihenstephan 34/70. Consequently, co-fermentation of this lager yeast strain with a Wickerhamomyces anomalus strain generated an increased fruity-flavour profile. This demonstrates that mixed fermentations utilizing non-Saccharomyces cerevisiae biodiversity can enhance the flavour profiles of fermented beverages.

Changes in volatile profile of soybean residue (okara) upon solid-state fermentation by yeasts.

Science.gov (United States)

Vong, Weng Chan; Liu, Shao-Quan

2017-01-01

Soybean residue (okara), a by-product of soymilk, is produced in large volumes by the soy food industry and is often discarded due to its undesirable flavour. As it contains a considerable amount of protein and fats, biotransformation of okara to improve its flavour presents an opportunity for alternative utilisation. This paper evaluated 10 yeasts in the solid-state fermentation of okara based on their volatile profiles as analysed with HS-SPME GC-MS/FID. Four 'dairy yeasts' (Geotrichum candidum, Yarrowia lipolytica, Debaryomyces hansenii and Kluyveromyces lactis) and six 'wine yeasts' (Saccharomyces cerevisiae, Lachancea thermotolerans, Metschnikowia pulcherrima, Pichia kluyveri, Torulaspora delbrueckii, and Williopsis saturnus) were studied. The main off-odourants in okara, hexanal and trans-2-hexenal, significantly decreased after fermentation due to their bioconversion into methyl ketones and/or esters. The okara fermented by dairy yeasts contained greater proportions of methyl ketones, while that by wine yeasts contained more ethyl and acetyl esters. Notably, the okara fermented by W. saturnus contained 13 esters and the total GC-FID peak area of esters was about 380 times that in fresh okara, leading to a perceptible fruity note. Okara can be exploited as an inexpensive substrate for bioflavour extraction and/or a more pleasant food ingredient via yeast fermentation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

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.

Production of fermentation aroma compounds by Saccharomyces cerevisiae wine yeasts: effects of yeast assimilable nitrogen on two model strains.

Science.gov (United States)

Carrau, Francisco M; Medina, Karina; Farina, Laura; Boido, Eduardo; Henschke, Paul A; Dellacassa, Eduardo

2008-11-01

The contribution of yeast fermentation metabolites to the aromatic profile of wine is well documented; however, the biotechnological application of this knowledge, apart from strain selection, is still rather limited and often contradictory. Understanding and modeling the relationship between nutrient availability and the production of desirable aroma compounds by different strains must be one of the main objectives in the selection of industrial yeasts for the beverage and food industry. In order to overcome the variability in the composition of grape juices, we have used a chemically defined model medium for studying yeast physiological behavior and metabolite production in response to nitrogen supplementation so as to identify an appropriate yeast assimilable nitrogen level for strain differentiation. At low initial nitrogen concentrations, strain KU1 produced higher quantities of esters and fatty acids whereas M522 produced higher concentrations of isoacids, gamma-butyrolactone, higher alcohols and 3-methylthio-1-propanol. We propose that although strains KU1 and M522 have a similar nitrogen consumption profile, they represent useful models for the chemical characterization of wine strains in relation to wine quality. The differential production of aroma compounds by the two strains is discussed in relation to their capacity for nitrogen usage and their impact on winemaking. The results obtained here will help to develop targeted metabolic footprinting methods for the discrimination of industrial yeasts.

Novel Biocontrol Methods for Listeria monocytogenes Biofilms in Food Production Facilities

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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

Novel Biocontrol Methods for Listeria monocytogenes Biofilms in Food Production Facilities

Science.gov (United States)

Gray, Jessica A.; Chandry, P. Scott; Kaur, Mandeep; Kocharunchitt, Chawalit; Bowman, John P.; Fox, Edward M.

2018-01-01

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 methods and their

Electronic Nose for Microbiological Quality Control of Food Products

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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.

Application of Bacteriocins and Protective Cultures in Dairy Food Preservation

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Célia C. G. Silva

2018-04-01

Full Text Available In the last years, consumers are becoming increasingly aware of the human health risk posed by the use of chemical preservatives in foods. In contrast, the increasing demand by the dairy industry to extend shelf-life and prevent spoilage of dairy products has appeal for new preservatives and new methods of conservation. Bacteriocins are antimicrobial peptides, which can be considered as safe since they can be easily degraded by proteolytic enzymes of the mammalian gastrointestinal tract. Also, most bacteriocin producers belong to lactic acid bacteria (LAB, a group that occurs naturally in foods and have a long history of safe use in dairy industry. Since they pose no health risk concerns, bacteriocins, either purified or excreted by bacteriocin producing strains, are a great alternative to the use of chemical preservatives in dairy products. Bacteriocins can be applied to dairy foods on a purified/crude form or as a bacteriocin-producing LAB as a part of fermentation process or as adjuvant culture. A number of applications of bacteriocins and bacteriocin-producing LAB have been reported to successful control pathogens in milk, yogurt, and cheeses. One of the more recent trends consists in the incorporation of bacteriocins, directly as purified or semi-purified form or in incorporation of bacteriocin-producing LAB into bioactive films and coatings, applied directly onto the food surfaces and packaging. This review is focused on recent developments and applications of bacteriocins and bacteriocin-producing LAB for reducing the microbiological spoilage and improve safety of dairy products.

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.

Dietary glucose regulates yeast consumption in adult Drosophila males

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Sebastien eLebreton

2014-12-01

Full Text Available The adjustment of feeding behavior in response to hunger and satiety contributes to homeostatic regulation in animals. The fruit fly Drosophila melanogaster feeds on yeasts growing on overripe fruit, providing nutrients required for adult survival, reproduction and larval growth. Here, we present data on how the nutritional value of food affects subsequent yeast consumption in Drosophila adult males. After a period of starvation, flies showed intensive yeast consumption. In comparison, flies stopped feeding after having access to a nutritive cornmeal diet. Interestingly, dietary glucose was equally efficient as the complex cornmeal diet. In contrast, flies fed with sucralose, a non-metabolizable sweetener, behaved as if they were starved. The adipokinetic hormone and insulin-like peptides regulate metabolic processes in insects. We did not find any effect of the adipokinetic hormone pathway on this modulation. Instead, the insulin pathway was involved in these changes. Flies lacking the insulin receptor did not respond to nutrient deprivation by increasing yeast consumption. Together these results show the importance of insulin in the regulation of yeast consumption in response to starvation in adult D. melanogaster males.

Non-canonical regulation of glutathione and trehalose biosynthesis characterizes non-Saccharomyces wine yeasts with poor performance in active dry yeast production

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Esther Gamero-Sandemetrio

2018-01-01

Full Text Available Several yeast species, belonging to Saccharomyces and non-Saccharomyces genera, play fundamental roles during spontaneous must grape fermentation, and recent studies have shown that mixed fermentations, co-inoculated with S. cerevisiae and non-Saccharomyces strains, can improve wine organoleptic properties. During active dry yeast (ADY production, antioxidant systems play an essential role in yeast survival and vitality as both biomass propagation and dehydration cause cellular oxidative stress and negatively affect technological performance. Mechanisms for adaptation and resistance to desiccation have been described for S. cerevisiae, but no data are available on the physiology and oxidative stress response of non-Saccharomyces wine yeasts and their potential impact on ADY production. In this study we analyzed the oxidative stress response in several non-Saccharomyces yeast species by measuring the activity of reactive oxygen species (ROS scavenging enzymes, e.g., catalase and glutathione reductase, accumulation of protective metabolites, e.g., trehalose and reduced glutathione (GSH, and lipid and protein oxidation levels. Our data suggest that non-canonical regulation of glutathione and trehalose biosynthesis could cause poor fermentative performance after ADY production, as it corroborates the corrective effect of antioxidant treatments, during biomass propagation, with both pure chemicals and food-grade argan oil.

Natural Diversity in Heat Resistance of Bacteria and Bacterial Spores: Impact on Food Safety and Quality.

Science.gov (United States)

den Besten, Heidy M W; Wells-Bennik, Marjon H J; Zwietering, Marcel H

2018-03-25

Heat treatments are widely used in food processing often with the aim of reducing or eliminating spoilage microorganisms and pathogens in food products. The efficacy of applying heat to control microorganisms is challenged by the natural diversity of microorganisms with respect to their heat robustness. This review gives an overview of the variations in heat resistances of various species and strains, describes modeling approaches to quantify heat robustness, and addresses the relevance and impact of the natural diversity of microorganisms when assessing heat inactivation. This comparison of heat resistances of microorganisms facilitates the evaluation of which (groups of) organisms might be troublesome in a production process in which heat treatment is critical to reducing the microbial contaminants, and also allows fine-tuning of the process parameters. Various sources of microbiological variability are discussed and compared for a range of species, including spore-forming and non-spore-forming pathogens and spoilage organisms. This benchmarking of variability factors gives crucial information about the most important factors that should be included in risk assessments to realistically predict heat inactivation of bacteria and spores as part of the measures for controlling shelf life and safety of food products.

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...... defined interaction medium (CDIM) was developed allowing growth of protective Lb. paracasei and P. freudenreichii subsp. shermaniii as well as the spoilage fungi, Penicillium spp., Rhodotorula mucilaginosa and Debaryomyces hansenii isolated from fermented dairy products. Lb. paracasei and P....... freudenreichii subsp. shermanii grew in CDIM and showed antifungal properties similar to those observed in milk-based systems. Most of the antifungal effect of the protective bacterial ferment was lost after removal of cells. This was explained by a marked decrease in diacetyl concentration, which...

Eubiotics for Food Security at Farm Level: Yeast Cell Wall Products and Their Antimicrobial Potential Against Pathogenic Bacteria.

Science.gov (United States)

Santovito, Elisa; Greco, Donato; Logrieco, Antonio F; Avantaggiato, Giuseppina

2018-06-06

The population increase in the last century was the first cause of the industrialization of animal productions, together with the necessity to satisfy the high food demand and the lack of space and land for the husbandry practices. As a consequence, the farmers moved from extensive to intensive agricultural systems and introduced new practices, such as the administration of antimicrobial drugs. Antibiotics were then used as growth promoters and for disease prevention. The uncontrolled and continuous use of antibiotics contributed to the spread of antibiotic resistance in animals, and this had adverse impacts on human health. This emergence led the European Union, in 2003, to ban the marketing and use of antibiotics as growth promoters, and for prophylaxis purposes from January 2006. This ban caused problems in farms, due to the decrease in animal performances (weight gain, feed conversion ratio, reproduction, etc.), and the rise in the incidence of certain diseases, such as those induced by Clostridium perfringens, Salmonella, Escherichia coli, and Listeria monocytogenes. The economic losses due to the ban increased the interest in researching alternative strategies for the prophylaxis of infectious diseases and for health and growth promotion, such as feed additives. Yeast-based materials, such as cell wall extract, represent promising alternatives to antibiotics, on the base of their prebiotic activity and their claimed capacity to bind enteropathogenic bacteria. Several authors reported examples of the effectiveness of yeast cell wall products in adsorbing bacteria, but there is a lack of knowledge on the mechanisms involved in this interaction. The purpose of this review is to provide an overview of the current approaches used for the control of pathogenic bacteria in feed, with a particular focus on the use of yeast-derived materials proposed to control zoonoses at farm level, and on their effect on animal health.

Reproducible analyses of microbial food for advanced life support systems

Science.gov (United States)

Petersen, Gene R.

1988-01-01

The use of yeasts in controlled ecological life support systems (CELSS) for microbial food regeneration in space required the accurate and reproducible analysis of intracellular carbohydrate and protein levels. The reproducible analysis of glycogen was a key element in estimating overall content of edibles in candidate yeast strains. Typical analytical methods for estimating glycogen in Saccharomyces were not found to be entirely aplicable to other candidate strains. Rigorous cell lysis coupled with acid/base fractionation followed by specific enzymatic glycogen analyses were required to obtain accurate results in two strains of Candida. A profile of edible fractions of these strains was then determined. The suitability of yeasts as food sources in CELSS food production processes is discussed.

Asian fungal fermented food

NARCIS (Netherlands)

Nout, M.J.R.; Aidoo, K.E.

2010-01-01

In Asian countries, there is a long history of fermentation of foods and beverages. Diverse micro-organisms, including bacteria, yeasts and moulds, are used as starters, and a wide range of ingredients can be made into fermented foods. The main raw materials include cereals, leguminous seeds,

From potential to reality. Yeasts derived from ethanol production for animal nutrition

International Nuclear Information System (INIS)

Fernandes, E.A.N.; Trevizam, A.B.; Nepomuceno, N.; Amorim, H.V.

1998-01-01

The high costs of cereals and vegetable protein supplements used for animal nutrition have directed much attention toward non-conventional alternative protein sources. Brazil has a significant potential to provide such material, since it is the world's largest producer of ethanol (13 billion liters per year) derived from fermentation by yeasts (sugar cane being the basic raw material). Distilleries are recovering surplus yeast to produce dry yeast for use in animal food formulations. With regard to the yeast biomass elemental composition, INAA analyses performed on a pool of samples from various different fermentations have shown the presence of various trace elements, e.g. As, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Na, Rb, Sc, Sm, Th, and Zn. This reinforces the need for additional studies concerning the suitability of yeast in terms of maximum tolerable levels of these elements in formulations for domestic animals. (author)

Tapping into yeast diversity.

Science.gov (United States)

Fay, Justin C

2012-11-01

Domesticated organisms demonstrate our capacity to influence wild species but also provide us with the opportunity to understand rapid evolution in the context of substantially altered environments and novel selective pressures. Recent advances in genetics and genomics have brought unprecedented insights into the domestication of many organisms and have opened new avenues for further improvements to be made. Yet, our ability to engineer biological systems is not without limits; genetic manipulation is often quite difficult. The budding yeast, Saccharomyces cerevisiae, is not only one of the most powerful model organisms, but is also the premier producer of fermented foods and beverages around the globe. As a model system, it entertains a hefty workforce dedicated to deciphering its genome and the function it encodes at a rich mechanistic level. As a producer, it is used to make leavened bread, and dozens of different alcoholic beverages, such as beer and wine. Yet, applying the awesome power of yeast genetics to understanding its origins and evolution requires some knowledge of its wild ancestors and the environments from which they were derived. A number of surprisingly diverse lineages of S. cerevisiae from both primeval and secondary forests in China have been discovered by Wang and his colleagues. These lineages substantially expand our knowledge of wild yeast diversity and will be a boon to elucidating the ecology, evolution and domestication of this academic and industrial workhorse.

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.

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

Survey Study of Lipid Effect on Nisin Nanoliposome Formation and Application in Pasteurized Milk as a Food Model

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Say-yed Hesameddin Tafreshi

2015-03-01

Full Text Available The use of bacteriocins, mainly nisin, is one of the most significant preservation technologies in food industries. Nisin encapsulation can improve stability and homogenous distribution in food matrices. In this study, liposomes of four various lipids (lipoid S 100, lipoid S PC-3, lipoid S PC and lipoid PC (DPPC were prepared by dehydration-rehydration method, compared for entrapment efficiency and lipid with the highest entrapment efficiency (DPPC was characterized. Inhibitory effects of encapsulated (DPPC nanoliposomes and free nisin on spoilage of pasteurized milk were also studied. Entrapment efficiency ranged from 14% (lipoid S 100 to 49% (DPPC. DPPC nanoliposomes were large unilamellar vesicles (LUV and had an asymmetric oval shape (elliptical with a mean diameter of 136 nm. Our study revealed that pasteurized milk spoilage was delayed by both of free and encapsulated nisin, but free nisin (with 38 days was significantly more efficient in comparison with encapsulated nisin (14 days.

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)

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...

Biogenic synthesis of Zinc oxide nanostructures from Nigella sativa seed: Prospective role as food packaging material inhibiting broad-spectrum quorum sensing and biofilm.

Science.gov (United States)

Al-Shabib, Nasser A; Husain, Fohad Mabood; Ahmed, Faheem; Khan, Rais Ahmad; Ahmad, Iqbal; Alsharaeh, Edreese; Khan, Mohd Shahnawaz; Hussain, Afzal; Rehman, Md Tabish; Yusuf, Mohammad; Hassan, Iftekhar; Khan, Javed Masood; Ashraf, Ghulam Md; Alsalme, Ali Mohammed; Al-Ajmi, Mohamed F; Tarasov, Vadim V; Aliev, Gjumrakch

2016-12-05

Bacterial spoilage of food products is regulated by density dependent communication system called quorum sensing (QS). QS control biofilm formation in numerous food pathogens and Biofilms formed on food surfaces act as carriers of bacterial contamination leading to spoilage of food and health hazards. Agents inhibiting or interfering with bacterial QS and biofilm are gaining importance as a novel class of next-generation food preservatives/packaging material. In the present study, Zinc nanostructures were synthesised using Nigella sativa seed extract (NS-ZnNPs). Synthesized nanostructures were characterized hexagonal wurtzite structure of size ~24 nm by UV-visible, XRD, FTIR and TEM. NS-ZnNPs demonstrated broad-spectrum QS inhibition in C. violaceum and P. aeruginosa biosensor strains. Synthesized nanostructures inhibited QS regulated functions of C. violaceum CVO26 (violacein) and elastase, protease, pyocyanin and alginate production in PAO1 significantly. NS-ZnNPs at sub-inhibitory concentrations inhibited the biofilm formation of four-food pathogens viz. C. violaceum 12472, PAO1, L. monocytogenes, E. coli. Moreover, NS-ZnNPs was found effective in inhibiting pre-formed mature biofilms of the four pathogens. Therefore, the broad-spectrum inhibition of QS and biofilm by biogenic Zinc oxide nanoparticles and it is envisaged that these nontoxic bioactive nanostructures can be used as food packaging material and/or as food preservative.

Generation of low-temperature air plasma for food processing

Science.gov (United States)

Stepanova, Olga; Demidova, Maria; Astafiev, Alexander; Pinchuk, Mikhail; Balkir, Pinar; Turantas, Fulya

2015-11-01

The project is aimed at developing a physical and technical foundation of generating plasma with low gas temperature at atmospheric pressure for food industry needs. As known, plasma has an antimicrobial effect on the numerous types of microorganisms, including those that cause food spoilage. In this work an original experimental setup has been developed for the treatment of different foods. It is based on initiating corona or dielectric-barrier discharge in a chamber filled with ambient air in combination with a certain helium admixture. The experimental setup provides various conditions of discharge generation (including discharge gap geometry, supply voltage, velocity of gas flow, content of helium admixture in air and working pressure) and allows for the measurement of the electrical discharge parameters. Some recommendations on choosing optimal conditions of discharge generation for experiments on plasma food processing are developed.

Behaviour of co-inoculated pathogenic and spoilage bacteria on poultry following several decontamination treatments.

Science.gov (United States)

Alonso-Hernando, Alicia; Capita, Rosa; Alonso-Calleja, Carlos

2012-10-01

The potential of chemical decontaminants to cause harmful effects on human health is among the causes of the rejection of antimicrobial treatments for removing surface contamination from poultry carcasses in the European Union. This study was undertaken to determine whether decontaminants might give a competitive advantage to pathogenic bacteria on poultry and involve a potential risk to consumer. A total of 144 chicken legs were co-inoculated with similar concentrations of pathogenic bacteria (Listeria monocytogenes, Staphylococcus aureus, Salmonella enterica serotype Enteritidis or Escherichia coli) and spoilage bacteria (Brochothrix thermosphacta or Pseudomonas fluorescens). Samples were dipped for 15min in solutions (w/v) of trisodium phosphate (12%; TSP), acidified sodium chlorite (1200ppm; ASC), citric acid (2%; CA), peroxyacids (220ppm; PA) or chlorine dioxide (50ppm; CD), or were left untreated (control). Microbiological analyses were carried out on day 0 and every 24h until day 7 of storage (at 10±1°C). The modified Gompertz equation was used as the primary model to fit observed data. TSP, ASC and CA were effective in extending the lag phase (L, ranging from 1.47±1.34days to 4.06±1.16days) and in decreasing the concentration of bacteria during the stationary phase (D, ranging from 2.46±0.51 log(10) cfu/cm(2) to 8.64±0.53 log(10) cfu/cm(2)), relative to the control samples (L values ranging from 0.59±0.38days and 2.52±2.28days, and D values ranging from 6.32±0.89 log(10) cfu/cm(2) to 9.39±0.39 log(10) cfu/cm(2), respectively). Both on untreated and on most decontaminated samples the overgrowth of spoilage bacteria among the species tested was observed throughout storage, suggesting that spoilage would occur prior to any noteworthy increase in the levels of pathogenic microorganisms. However, L. monocytogenes counts similar to, or higher than, those for spoilage bacteria were observed on samples treated with TSP, ASC or CA, suggesting that these

Life History Responses and Gene Expression Profiles of the Nematode Pristionchus pacificus Cultured on Cryptococcus Yeasts.

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Gaurav V Sanghvi

Full Text Available Nematodes, the earth's most abundant metazoa are found in all ecosystems. In order to survive in diverse environments, they have evolved distinct feeding strategies and they can use different food sources. While some nematodes are specialists, including parasites of plants and animals, others such as Pristionchus pacificus are omnivorous feeders, which can live on a diet of bacteria, protozoans, fungi or yeast. In the wild, P. pacificus is often found in a necromenic association with beetles and is known to be able to feed on a variety of microbes as well as on nematode prey. However, in laboratory studies Escherichia coli OP50 has been used as standard food source, similar to investigations in Caenorhabditis elegans and it is unclear to what extent this biases the obtained results and how relevant findings are in real nature. To gain first insight into the variation in traits induced by a non-bacterial food source, we study Pristionchus-fungi interactions under laboratory conditions. After screening different yeast strains, we were able to maintain P. pacificus for at least 50-60 generations on Cryptococcus albidus and Cryptococcus curvatus. We describe life history traits of P. pacificus on both yeast strains, including developmental timing, survival and brood size. Despite a slight developmental delay and problems to digest yeast cells, which are both reflected at a transcriptomic level, all analyses support the potential of Cryptococcus strains as food source for P. pacificus. In summary, our work establishes two Cryptococcus strains as alternative food source for P. pacificus and shows change in various developmental, physiological and morphological traits, including the transcriptomic profiles.

Design of a papain immobilized antimicrobial food package with curcumin as a crosslinker.

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Cynthya Maria Manohar

Full Text Available Contamination of food products by spoilage and pathogenic microorganisms during post process handling is one of the major causes for food spoilage and food borne illnesses. The present green sustainable approach describes the covalent immobilization of papain to LDPE (low density polyethylene, HDPE (high density polyethylene, LLDPE (linear low density polyethylene and PCL (polycaprolactam with curcumin as the photocrosslinker. About 50% of curcumin and 82-92% of papain were successfully immobilized on these polymers. After 30 days, the free enzyme retained 87% of its original activity, while the immobilized enzyme retained more than 90% of its activity on these polymers. Papain crosslinked to LLDPE exhibited the best antibiofilm properties against Acinetobacter sp. KC119137.1 and Staphylococcus aureus NCIM 5021 when compared to the other three polymers, because of the highest amount of enzyme immobilized on this surface. Papain acts by damaging the cell membrane. The enzyme is able to reduce the amount of carbohydrate and protein contents in the biofilms formed by these organisms. Meat wrapped with the modified LDPE and stored at 4°C showed 9 log reduction of these organisms at the end of the seventh day when compared to samples wrapped with the bare polymer. This method of crosslinking can be used on polymers with or without functional groups and can be adopted to bind any type of antimicrobial agent.

Design of a Papain Immobilized Antimicrobial Food Package with Curcumin as a Crosslinker

Science.gov (United States)

Sivakumar, Ponnurengam Malliappan; Doble, Mukesh

2015-01-01

Contamination of food products by spoilage and pathogenic microorganisms during post process handling is one of the major causes for food spoilage and food borne illnesses. The present green sustainable approach describes the covalent immobilization of papain to LDPE (low density polyethylene), HDPE (high density polyethylene), LLDPE (linear low density polyethylene) and PCL (polycaprolactam) with curcumin as the photocrosslinker. About 50% of curcumin and 82-92% of papain were successfully immobilized on these polymers. After 30 days, the free enzyme retained 87% of its original activity, while the immobilized enzyme retained more than 90% of its activity on these polymers. Papain crosslinked to LLDPE exhibited the best antibiofilm properties against Acinetobacter sp. KC119137.1 and Staphylococcus aureus NCIM 5021 when compared to the other three polymers, because of the highest amount of enzyme immobilized on this surface. Papain acts by damaging the cell membrane. The enzyme is able to reduce the amount of carbohydrate and protein contents in the biofilms formed by these organisms. Meat wrapped with the modified LDPE and stored at 4°C showed 9 log reduction of these organisms at the end of the seventh day when compared to samples wrapped with the bare polymer. This method of crosslinking can be used on polymers with or without functional groups and can be adopted to bind any type of antimicrobial agent. PMID:25906061

Design of a papain immobilized antimicrobial food package with curcumin as a crosslinker.

Science.gov (United States)

Manohar, Cynthya Maria; Prabhawathi, Veluchamy; Sivakumar, Ponnurengam Malliappan; Doble, Mukesh

2015-01-01

Contamination of food products by spoilage and pathogenic microorganisms during post process handling is one of the major causes for food spoilage and food borne illnesses. The present green sustainable approach describes the covalent immobilization of papain to LDPE (low density polyethylene), HDPE (high density polyethylene), LLDPE (linear low density polyethylene) and PCL (polycaprolactam) with curcumin as the photocrosslinker. About 50% of curcumin and 82-92% of papain were successfully immobilized on these polymers. After 30 days, the free enzyme retained 87% of its original activity, while the immobilized enzyme retained more than 90% of its activity on these polymers. Papain crosslinked to LLDPE exhibited the best antibiofilm properties against Acinetobacter sp. KC119137.1 and Staphylococcus aureus NCIM 5021 when compared to the other three polymers, because of the highest amount of enzyme immobilized on this surface. Papain acts by damaging the cell membrane. The enzyme is able to reduce the amount of carbohydrate and protein contents in the biofilms formed by these organisms. Meat wrapped with the modified LDPE and stored at 4°C showed 9 log reduction of these organisms at the end of the seventh day when compared to samples wrapped with the bare polymer. This method of crosslinking can be used on polymers with or without functional groups and can be adopted to bind any type of antimicrobial agent.

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

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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.

Yeast dynamics during spontaneous fermentation of mawe and tchoukoutou, two traditional products from Benin

DEFF Research Database (Denmark)

Greppi, Anna; Rantisou, Kalliopi; Padonou, Wilfrid

2013-01-01

Mawe and tchoukoutou are two traditional fermented foods largely consumed in Benin, West Africa. Their preparations remain as a house art and they are the result of spontaneous fermentation processes. In this study, dynamics of the yeast populations occurring during spontaneous fermentations...... of mawe and tchoukoutou were investigated using both culture-dependent and -independent approaches. For each product, two productions were followed. Samples were taken at different fermentation times and yeasts were isolated, resulting in the collection of 177 isolates. They were identified by the PCR......-DGGE technique followed by the sequencing of the D1/D2 domain of the 26S rRNA gene. The predominant yeast species identified were typed by rep-PCR. Candida krusei was the predominant yeast species in mawe fermentation followed by Candida glabrata and Kluyveromyces marxianus. Other yeast species were detected...

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...

Fructanase and fructosyltransferase activity of non-Saccharomyces yeasts isolated from fermenting musts of Mezcal.

Science.gov (United States)

Arrizon, Javier; Morel, Sandrine; Gschaedler, Anne; Monsan, Pierre

2012-04-01

Fructanase and fructosyltransferase are interesting for the tequila process and prebiotics production (functional food industry). In this study, one hundred thirty non-Saccharomyces yeasts isolated from "Mezcal de Oaxaca" were screened for fructanase and fructosyltransferase activity. On solid medium, fifty isolates grew on Agave tequilana fructans (ATF), inulin or levan. In liquid media, inulin and ATF induced fructanase activities of between 0.02 and 0.27U/ml depending of yeast isolate. High fructanase activity on sucrose was observed for Kluyveromyces marxianus and Torulaspora delbrueckii, while the highest fructanase activity on inulin and ATF was observed for Issatchenkia orientalis, Cryptococcus albidus, and Candida apicola. Zygosaccharomyces bisporus and Candida boidinii had a high hydrolytic activity on levan. Sixteen yeasts belonging to K. marxianus, T. delbrueckii and C. apicola species were positive for fructosyltransferase activity. Mezcal microbiota proved to showed to be a source for new fructanase and fructosyltransferases with potential application in the tequila and food industry. Copyright © 2012 Elsevier Ltd. All rights reserved.

Shelf-stable food through high dose irradiation

International Nuclear Information System (INIS)

Placek, V.; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M.

2004-01-01

Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO x -containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested

Shelf-stable food through high dose irradiation

Energy Technology Data Exchange (ETDEWEB)

Placek, V. E-mail: pla@ujv.cz; Svobodova, V.; Bartonicek, B.; Rosmus, J.; Camra, M

2004-10-01

Irradiation of food with high doses (radappertization) is a way, how to prepare shelf-stable ready-to-eat food. The radappertization process requires that the food be heated at first to an internal temperature of at least 75 deg. C to inactivate autolytic enzyme, which could cause the spoilage during storage without refrigeration. In order to prevent radiation induced changes in sensory properties (off flavors, odors, undesirable color change, etc.) the food was vacuum packed and irradiated in frozen state at -30 deg. C or less to a minimum dose of 35 kGy. Such products have characteristics of fresh food prepared for eating even if they are stored for long time under tropical conditions. The wholesomeness (safety for consumption) has been confirmed during 40 years of testing. Within the NRI Rez 10 kinds of shelf-stable meat products have been prepared. The meat was cooked, vacuum packed in SiO{sub x}-containing pouch, freezed in liquid nitrogen and irradiated with electron beam accelerator. The microbial, chemical, and organoleptic properties have been tested.

77 FR 52228 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Vitamin D2

Science.gov (United States)

2012-08-29

... D2 Bakers Yeast AGENCY: Food and Drug Administration, HHS. ACTION: Final rule. SUMMARY: The Food and..., 379e. 0 2. Section 172.381 is added to subpart D to read as follows: Sec. 172.381 Vitamin D2 bakers...

Advances of electronic nose and its application in fresh foods: A review.

Science.gov (United States)

Shi, Hao; Zhang, Min; Adhikari, Benu

2017-06-30

The science and technology aspects of electronic nose (E-nose) has been developed rapidly in last decade (2006-2016). This paper reviews of the publications that that cover the developments in science and technological aspects of electronic nose together with its application in fresh foods. The first part of this review covers the sensing and pattern recognition system (PR) of E-nose. The second part covers the application of E-nose in classification, flavor detection, and evaluation of spoilage in fresh foods area. With more new sensor materials to be found and more combination between E-nose and other analysis technologies, the usages of E-nose in fresh foods will have wider prospects.

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

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...... small amounts of biogenic amines in this product. The elimination of P. phosphoreum by freezing allowed this bacteria to be identified as the SSO in fresh MAP salmon.Significance and Impact of the Study: The identification of P. phosphoreum as the SSO in fresh MAP salmon facilitates the development...

Yeast diversity in rice-cassava fermentations produced by the indigenous Tapirapé people of Brazil

DEFF Research Database (Denmark)

Schwan, Rosane F.; Almeida, Euziclei G.; Souza-Dias, Maria Aparecida G.

2007-01-01

and peanuts. A fermentation using rice and cassava was conducted, and samples were collected at 4-h intervals for microbial analysis. The yeast population was low at the beginning of the fermentation and reached 6.9 x 10(7) CFU mL(-1) after 48 h. During the fermentation process common yeast species were......The Tapirapé people of the Tapi'itãwa tribe of Brazil produce several fermented foods and beverages, one of which is called 'cauim'. This beverage usually makes up the main staple food for adults and children. Several substrates are used in its production, including cassava, rice, corn, maize...... identified by sequencing of the D1/D2 domain of the large-subunit (26S) rRNA gene. The predominant yeast species found was Candida tropicalis. Candida intermedia, Candida parapsilosis, Pichia guilliermondii, Saccharomyces cerevisiae and Trichosporon asahii were also found in high numbers during...

Characterisation and detection of spoilage mould responsible for black spot in dry-cured fermented sausages.

Science.gov (United States)

Lozano-Ojalvo, Daniel; Rodríguez, Alicia; Cordero, Mirian; Bernáldez, Victoria; Reyes-Prieto, Mariana; Córdoba, Juan J

2015-02-01

Moulds responsible for black spot spoilage of dry-cured fermented sausages were characterised. For this purpose, samples were taken from those dry-cured fermented sausages which showed black spot alteration. Most of the mould strains were first tentatively identified as Penicillium spp. due to their morphological characteristics in different culture conditions, with one strain as Cladosporium sp. The Cladosporium strain was the only one which provoked blackening in culture media. This strain was further characterised by sequencing of ITS1-5.8S-ITS2 rRNA and β-tubulin genes. This mould strain was able to reproduce black spot formation in dry-cured fermented sausage 'salchichón' throughout the ripening process. In addition, a specific and sensitive real-time PCR method was also developed to detect Cladosporium oxysporum responsible for the black spot formation in sausages. This method could be of great interest for the meat industry to detect samples contaminated with this mould before spoilage of product avoiding economic losses for this sector.

Processing of nonedible plant wastes to obtain furfural and yeasts

Energy Technology Data Exchange (ETDEWEB)

Golowin, W.W.

1977-01-01

The technology of furfural and yeast production from hydrolyzates of wastes from the food and wood-processing industries is detailed. For furfural manufacturing, the pentosan-containing raw material is treated with H/sub 2/SO/sub 4/ and steam-hydrolyzed, the furfural-containing vapors are condensed and separated from non-condensing gases, and the furfural is isolated from the condensate, purified and stabilized. After the furfural hydrolysis, the pressure is decreased from 3 to 1.2 atm, a 0.5% H/sub 2/SO/sub 4/ solution is added, and a hexose-containing hydrolyzate is transferred for neutralization and yeast culturing.

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

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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.

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.

Radiation processing of food: a promising technology to ensure food safety and security

International Nuclear Information System (INIS)

Gautam, S.

2016-01-01

Radiation processing of food involves controlled application of energy from ionizing radiations. Approved sources of radiation for food processing are radioisotopes (Cobalt-60 and Caesium-137), electron beam (up to 10 MeV) and X-rays (up to 5 MeV). Radiation processing of food is carried out in an irradiation chamber shielded by 1.5 - 1.8 m thick concrete walls. Food, either pre-packed or in-bulk, placed in suitable containers is sent into the irradiation chamber with the help of an automatic conveyor. Major benefits achieved by radiation processing of food are: (i) inhibition of sprouting of tubers and bulbs; (ii) disinfestations of insect pests in agricultural commodities; (iii) delay in ripening and senescence of fruits and vegetables; (iv) destruction of microbes responsible for spoilage, and (v) elimination of pathogens and parasites of public health importance. Irradiation produces very little chemical changes in food. The majority of changes are similar to those by other preservation methods like heat. The radiolytic products and free radicals produced are identical to those present in foods subjected to treatment such as cooking and canning. None of the changes known to occur have been found to be harmful. Twelve food irradiation plants have been commissioned till date in the private sector in India. Two plants set by Government of India (Radiation Processing Plant, Vashi, Navi Mumbai; and KRUSHAK, Lasalgaon, Nashik) are also operational. Volume of food irradiated in India has been steadily increasing. Recent development in the area of food irradiation in India include harmonization of food irradiation rules with international regulation

CRISPR-Cas Technologies and Applications in Food Bacteria.

Science.gov (United States)

Stout, Emily; Klaenhammer, Todd; Barrangou, Rodolphe

2017-02-28

Clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) proteins form adaptive immune systems that occur in many bacteria and most archaea. In addition to protecting bacteria from phages and other invasive mobile genetic elements, CRISPR-Cas molecular machines can be repurposed as tool kits for applications relevant to the food industry. A primary concern of the food industry has long been the proper management of food-related bacteria, with a focus on both enhancing the outcomes of beneficial microorganisms such as starter cultures and probiotics and limiting the presence of detrimental organisms such as pathogens and spoilage microorganisms. This review introduces CRISPR-Cas as a novel set of technologies to manage food bacteria and offers insights into CRISPR-Cas biology. It primarily focuses on the applications of CRISPR-Cas systems and tools in starter cultures and probiotics, encompassing strain-typing, phage resistance, plasmid vaccination, genome editing, and antimicrobial activity.

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.

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.

Distinct Domestication Trajectories in Top-Fermenting Beer Yeasts and Wine Yeasts.

Science.gov (United States)

Gonçalves, Margarida; Pontes, Ana; Almeida, Pedro; Barbosa, Raquel; Serra, Marta; Libkind, Diego; Hutzler, Mathias; Gonçalves, Paula; Sampaio, José Paulo

2016-10-24

Beer is one of the oldest alcoholic beverages and is produced by the fermentation of sugars derived from starches present in cereal grains. Contrary to lager beers, made by bottom-fermenting strains of Saccharomyces pastorianus, a hybrid yeast, ale beers are closer to the ancient beer type and are fermented by S. cerevisiae, a top-fermenting yeast. Here, we use population genomics to investigate (1) the closest relatives of top-fermenting beer yeasts; (2) whether top-fermenting yeasts represent an independent domestication event separate from those already described; (3) whether single or multiple beer yeast domestication events can be inferred; and (4) whether top-fermenting yeasts represent non-recombinant or recombinant lineages. Our results revealed that top-fermenting beer yeasts are polyphyletic, with a main clade composed of at least three subgroups, dominantly represented by the German, British, and wheat beer strains. Other beer strains were phylogenetically close to sake, wine, or bread yeasts. We detected genetic signatures of beer yeast domestication by investigating genes previously linked to brewing and using genome-wide scans. We propose that the emergence of the main clade of beer yeasts is related with a domestication event distinct from the previously known cases of wine and sake yeast domestication. The nucleotide diversity of the main beer clade more than doubled that of wine yeasts, which might be a consequence of fundamental differences in the modes of beer and wine yeast domestication. The higher diversity of beer strains could be due to the more intense and different selection regimes associated to brewing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prions in yeast

OpenAIRE

Bezdíčka, Martin

2013-01-01

The thesis describes yeast prions and their biological effects on yeast in general. It defines the basic characteristics of yeast prions, that distinguish prions from other proteins. The thesis introduces various possibilities of prion formation, and propagation as well as specific types of yeast prions, including various functions of most studied types of prions. The thesis also focuses on chaperones that affect the state of yeast prions in cells. Lastly, the thesis indicates similarities be...

Inactivation of food spoilage microorganisms by hydrodynamic cavitation to achieve pasteurization and sterilization of fluid foods.

Science.gov (United States)

Milly, P J; Toledo, R T; Harrison, M A; Armstead, D

2007-11-01

Hydrodynamic cavitation is the formation of gas bubbles in a fluid due to pressure fluctuations induced by mechanical means. Various high-acid (pH hydrodynamic cavitation reactor to determine if commercial sterility can be achieved at reduced processing temperatures. Sporicidal properties of the process were also tested on a low-acid (pH > [corrected] 4.6) fluid food. Fluid foods were pumped under pressure into a hydrodynamic cavitation reactor and subjected to 2 rotor speeds and flow rates to achieve 2 designated exit temperatures. Thermal inactivation kinetics were used to determine heat-induced lethality for all organisms. Calcium-fortified apple juice processed at 3000 and 3600 rpm rotor speeds on the reactor went through a transient temperature change from 20 to 65.6 or 76.7 degrees C and the total process lethality exceeded 5-log reduction of Lactobacillus plantarum and Lactobacillus sakei cells, and Zygosaccharomyces bailii cells and ascospores. Tomato juice inoculated with Bacillus coagulans spores and processed at 3000 and 3600 rpm rotor speeds endured a transient temperature from 37.8 to 93.3 or 104.4 degrees C with viable CFU reductions of 0.88 and 3.10 log cycles, respectively. Skim milk inoculated with Clostridium sporogenes putrefactive anaerobe 3679 spores and processed at 3000 or 3600 rpm rotor speeds endured a transient temperature from 48.9 to 104.4 or 115.6 degrees C with CFU reductions of 0.69 and 2.84 log cycles, respectively. Utilizing hydrodynamic cavitation to obtain minimally processed pasteurized low-acid and commercially sterilized high-acid fluid foods is possible with appropriate process considerations for different products.

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.

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

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)

Spoilage Science

Science.gov (United States)

Science and Children, 2005

2005-01-01

Have you ever tucked away a piece of fruit for later and returned to find it past its prime? Or found some leftovers that had outlived their welcome in the refrigerator? Whether it's fresh or processed, all food eventually spoils. Methods such as freezing, canning, and the use of preservatives lengthen the lifespan of foods, and we--and the modern…

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.

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...

Microbial Quality and Shelf Life of Blueberry Purée Developed Using Cavitation Technology.

Science.gov (United States)

Fan, Lihua; Martynenko, Alex; Doucette, Craig; Hughes, Timothy; Fillmore, Sherry

2018-03-01

Blueberry purée was developed using hydrodynamic cavitation technology. The product was made from entire blueberries without adding any food additives. In this study, microbial reduction following each processing stage (at the industry setting) and after product pasteurization at 86, 88, 90, 92, 94, and 96 °C was investigated. Microbial quality including total plate counts, yeast and molds, and heat-resistant molds counts was determined. Shelf life of pasteurized products stored for up to 24 weeks at room temperature were assessed for microbial quality, soluble solids (°Brix), titratable acidity (citric acid %), pH, viscosity (cP) and flow rate (cm/30 s). Our results indicated that heat-resistant molds, initially present in frozen blueberries with counts at 2.03 log CFU/200g, were totally inactivated at 94 to 96 °C with 1 to 2 min holding time. Shelf life study showed that no product spoilage was caused by bacteria, yeasts and heat-resistant molds along with non-significant changes of textural characteristics. This study provided useful information for the food industry to develop variety of fruit purée products with no wastes of fruit materials. This study provides useful information for the food industry to develop safe liquid food products using cavitation technology without wasting any raw materials. © 2018 Institute of Food Technologists®.

A microbial spoilage profile of half shell Pacific oysters (Crassostrea gigas) and Sydney rock oysters (Saccostrea glomerata).

Science.gov (United States)

Madigan, Thomas L; Bott, Nathan J; Torok, Valeria A; Percy, Nigel J; Carragher, John F; de Barros Lopes, Miguel A; Kiermeier, Andreas

2014-04-01

This study aimed to assess bacterial spoilage of half shell Pacific and Sydney rock oysters during storage using microbial culture and 16S rRNA pyrosequencing. Odour and pH of oyster meats were also investigated. Estimation of microbiological counts by microbial culture highlighted growth of psychrotrophic bacteria. During storage, odour scores (a score describing deterioration of fresh odours where a score of 1 is fresh and 4 is completely spoiled) increased from 1.0 to 3.0 for Pacific oysters and from 1.3 to 3.4 for Sydney rock oysters. pH results obtained for both species fluctuated during storage (range 6.28-6.73) with an overall increase at end of storage. Pyrosequencing revealed that the majority of bacteria at Day 0 represented taxa from amongst the Proteobacteria, Tenericutes and Spirochaetes that have not been cultured and systematically described. During storage, Proteobacteria became abundant with Pseudoalteromonas and Vibrio found to be dominant in both oyster species at Day 7. Analysis of the pyrosequencing data showed significant differences in bacterial profiles between oyster species and storage time (both P = 0.001). As oysters spoiled, bacterial profiles between oyster species became more similar indicating a common spoilage profile. Data presented here provides detailed insight into the changing bacterial profile of shucked oysters during storage and has identified two genera, Pseudoalteromonas and Vibrio, as being important in spoilage of shucked oysters. Copyright © 2013 Elsevier Ltd. All rights reserved.

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...

Antimicrobial activity of broccoli (Brassica oleracea var. italica) cultivar Avenger against pathogenic bacteria, phytopathogenic filamentous fungi and yeast.

Science.gov (United States)

Pacheco-Cano, R D; Salcedo-Hernández, R; López-Meza, J E; Bideshi, D K; Barboza-Corona, J E

2018-01-01

The objective of this study was to show whether the edible part of broccoli has antibacterial and antifungal activity against micro-organism of importance in human health and vegetable spoilage, and to test if this effect was partially due to antimicrobial peptides (AMPs). Crude extracts were obtained from florets and stems of broccoli cultivar Avenger and the inhibitory effect was demonstrated against pathogenic bacteria (Bacillus cereus, Staphylococcus xylosus, Staphylococcus aureus, Shigella flexneri, Shigella sonnei, Proteus vulgaris), phytopathogenic fungi (Colletotrichum gloeosporioides, Asperigillus niger) and yeasts (Candida albicans and Rhodotorula sp.). It was shown that samples treated with proteolytic enzymes had a reduction of approximately 60% in antibacterial activity against Staph. xylosus, suggesting that proteinaceous compounds might play a role in the inhibitory effect. Antimicrobial components in crude extracts were thermoresistant and the highest activity was observed under acidic conditions. It was shown that antifungal activity of broccoli's crude extracts might not be attributed to chitinases. Organic broccoli cultivar Avenger has antimicrobial activity against pathogenic bacteria, yeast and phytophatogenic fungi. Data suggest that this effect is partially due to AMPs. Broccoli's crude extracts have activity not only against pathogenic bacteria but also against phytophatogenic fungi of importance in agriculture. We suggest for first time that the inhibitory effect is probably due to AMPs. © 2017 The Society for Applied Microbiology.

Recent Advances in Food Processing Using High Hydrostatic Pressure Technology.

Science.gov (United States)

Wang, Chung-Yi; Huang, Hsiao-Wen; Hsu, Chiao-Ping; Yang, Binghuei Barry

2016-01-01

High hydrostatic pressure is an emerging non-thermal technology that can achieve the same standards of food safety as those of heat pasteurization and meet consumer requirements for fresher tasting, minimally processed foods. Applying high-pressure processing can inactivate pathogenic and spoilage microorganisms and enzymes, as well as modify structures with little or no effects on the nutritional and sensory quality of foods. The U.S. Food and Drug Administration (FDA) and the U.S. Department of Agriculture (USDA) have approved the use of high-pressure processing (HPP), which is a reliable technological alternative to conventional heat pasteurization in food-processing procedures. This paper presents the current applications of HPP in processing fruits, vegetables, meats, seafood, dairy, and egg products; such applications include the combination of pressure and biopreservation to generate specific characteristics in certain products. In addition, this paper describes recent findings on the microbiological, chemical, and molecular aspects of HPP technology used in commercial and research applications.

Synergism between hydrogen peroxide and seventeen acids against five agri-food-borne fungi and one yeast strain.

Science.gov (United States)

Martin, H; Maris, P

2012-12-01

The objective of this study was to evaluate fungicidal efficacy of hydrogen peroxide administered in combination with 17 mineral and organic acids authorized for use in the food industry. The assays were performed on a 96-well microplate using a microdilution technique based on the checkerboard titration method. The six selected strains (one yeast and five fungi) were reference strains and strains representative of contaminating fungi found in the food industry. Each synergistic hydrogen peroxide/acid combination found after fifteen minutes contact time at 20 °C in distilled water was then tested in conditions simulating four different use conditions. Twelve combinations were synergistic in distilled water, eleven of these remained synergistic with one or more of the four mineral and organic interfering substances selected. Hydrogen peroxide/formic acid combination remained effective against four strains and was never antagonistic against the other two fungi. Combinations with propionic acid and acetic acid stayed synergistic against two strains. Those with oxalic acid and lactic acid kept their synergism only against Candida albicans. No synergism was detected against Penicillium cyclopium. Synergistic combinations of disinfectants were revealed, among them the promising hydrogen peroxide/formic acid combination. A rapid screening method developed in our laboratory for bacteria was adapted to fungi and used to reveal the synergistic potential of disinfectants and/or sanitizers combinations. © 2012 The Society for Applied Microbiology.

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.

Food irradiation: Activities and potentialities

Science.gov (United States)

Doellstaedt, R.; Huebner, G.

After the acceptance of food irradiation up to an overall average dose of 10 kGy recommended by the Joint FAO/IAEA/WHO Expert Committee on the Wholesomeness of Irradiated Food in October 1980, the G.D.R. started a programme for the development of techniques for food irradiation. A special onion irradiator was designed and built as a pilot plant for studying technological and economic parameters of the irradiation of onions. The new principle of bulk-cargo irradiation allows the integration of this technology into the usual harvest technology for onions on the way from field to storage. Scientific and applied research work has been carried out in the past 3 yr on the irradiation of spices, potatoes, eviscerated chicken, animal feeds, fodder yeast, drugs and vaccines. In connection with the irradiation of eviscerated chicken, fodder yeast and animal feeds the basis of an antisalmonella programme has been discussed. Germ-count-reduced spices were employed for the production of test charges of preserves and tinned products. The results have led to the decision to design and build a new multipurpose irradiator for food irradiation. In order to cover the legal aspects of food irradiation the Ministry of Health issued regulations concerning the recommendation of irradiated food in the G.D.R.

Designer Yeasts for the Fermentation Industry of the 21st Century

Directory of Open Access Journals (Sweden)

Isak S. Pretorius

2003-01-01

Full Text Available The budding yeast, Saccharomyces cerevisiae, has enjoyed a long and distinguished history in the fermention industry. Owing to its efficiency in producing alcohol, S. cerevisiae is, without doubt, the most important commercial microorganism with GRAS (Generally Regarded As Safe status. By brewing beer and sparkling wine, mankind’s oldest domesticated organism made possible the world’s first biotechnological processes. With the emergence of modern molecular genetics, S. cerevisiae has again been harnessed to shift the frontiers of mankind’s newest revolution, genetic engineering. S. cerevisiae is at the forefront of many of these developments in modern biotechnology. Consequently, the industrial importance of S. cerevisiae has extended beyond traditional fermentation. Today, the products of yeast biotechnologies impinge on many commercially important sectors, including food, beverages, biofuels, chemicals, industrial enzymes, pharmaceuticals, agriculture and the environment. Nevertheless, since ethyl alcohol produced by yeast fermentation is likely to remain the foremost worldwide biotechnological commodity for the foreseeable future, this review focuses on advances made with respect to the development of tailor- made yeast strains for the fermented beverage and biofuel industries.

Radiation stimulation of yeast crops for increasing output of alcohol and baker yeasts

International Nuclear Information System (INIS)

Vlad, E.; Marsheu, P.

1974-01-01

The purpose of this study was to stimulate by gamma radiation the existing commercial types of yeast so as to obtain yeasts that would better reflect the substrate and have improved reproductive capacity. The experiments were conducted under ordinary conditions using commercial yeasts received from one factory producing alcohol and bakery yeasts and isolated as pure cultures. Irradiating yeast cultures with small doses (up to 10 krad) was found to stimulate the reproduction and fermenting activity of yeast cells as manifested in increased accumulation of yeast biomass and greater yield of ethyl alcohol. (E.T.)

Yeast Breads. Learning Activity Pack and Instructor's Guide 5.15a. Commercial Foods and Culinary Arts Competency-Based Series. Section 5: Basic Food Preparation.

Science.gov (United States)

Florida State Univ., Tallahassee. Center for Studies in Vocational Education.

This document consists of a learning activity packet (LAP) for the student and an instructor's guide for the teacher. The LAP is intended to acquaint occupational home economics students with yeast breads and their ingredients. Illustrated information sheets and learning activities are provided in these areas: yeast breads and their ingredients,…

African fermented dairy products - Overview of predominant technologically important microorganisms focusing on African Streptococcus infantarius variants and potential future applications for enhanced food safety and security.

Science.gov (United States)

Jans, Christoph; Meile, Leo; Kaindi, Dasel Wambua Mulwa; Kogi-Makau, Wambui; Lamuka, Peter; Renault, Pierre; Kreikemeyer, Bernd; Lacroix, Christophe; Hattendorf, Jan; Zinsstag, Jakob; Schelling, Esther; Fokou, Gilbert; Bonfoh, Bassirou

2017-06-05

Milk is a major source of nutrients, but can also be a vehicle for zoonotic foodborne diseases, especially when raw milk is consumed. In Africa, poor processing and storage conditions contribute to contamination, outgrowth and transmission of pathogens, which lead to spoilage, reduced food safety and security. Fermentation helps mitigate the impact of poor handling and storage conditions by enhancing shelf life and food safety. Traditionally-fermented sour milk products are culturally accepted and widely distributed in Africa, and rely on product-specific microbiota responsible for aroma, flavor and texture. Knowledge of microbiota and predominant, technologically important microorganisms is critical in developing products with enhanced quality and safety, as well as sustainable interventions for these products, including Africa-specific starter culture development. This narrative review summarizes current knowledge of technologically-important microorganisms of African fermented dairy products (FDP) and raw milk, taking into consideration novel findings and taxonomy when re-analyzing data of 29 publications covering 25 products from 17 African countries. Technologically-important lactic acid bacteria such as Lactococcus lactis and Streptococcus infantarius subsp. infantarius (Sii), Lactobacillus spp. and yeasts predominated in raw milk and FDP across Africa. Re-analysis of data also suggests a much wider distribution of Sii and thus a potentially longer history of use than previously expected. Therefore, evaluating the role and safety of African Sii lineages is important when developing interventions and starter cultures for FDP in Africa to enhance food safety and food security. In-depth functional genomics, epidemiologic investigations and latest identification approaches coupled with stakeholder involvement will be required to evaluate the possibility of African Sii lineages as novel food-grade Streptococcus lineage. Copyright © 2017 The Authors. Published by

Development of a Quantitative PCR Assay for Thermophilic Spore-Forming Geobacillus stearothermophilus in Canned Food.

Science.gov (United States)

Nakano, Miyo

2015-01-01

The thermophilic spore forming bacteria Geobacillus stearothermophilus is recognized as a major cause of spoilage in canned food. A quantitative real-time PCR assay was developed to specifically detect and quantify the species G. stearothermophilus in samples from canned food. The selected primer pairs amplified a 163-bp fragment of the 16S rRNA gene in a specific PCR assay with a detection limit of 12.5 fg of pure culture DNA, corresponding to DNA extracted from approximately 0.7 CFU/mL of G. stearothermophilus. Analysis showed that the bacterial species G. stearothermophilus was not detected in any canned food sample. Our approach presented here will be useful for tracking or quantifying species G. stearotethermophilus in canned food and ingredients.

Treatment and Valorization of Palm Oil Mill Effluent through Production of Food Grade Yeast Biomass

OpenAIRE

Joy O. Iwuagwu; J. Obeta Ugwuanyi

2014-01-01

Palm oil mill effluent (POME) is high strength wastewater derived from processing of palm fruit. It is generated in large quantities in all oil palm producing nations where it is a strong pollutant amenable to microbial degradation being rich in organic carbon, nitrogen, and minerals. Valorization and treatment of POME with seven yeast isolates was studied under scalable conditions by using POME to produce value-added yeast biomass. POME was used as sole source of carbon and nitrogen and the ...

Inhibitory Properties of Lactic Acid Bacteria against Moulds Associated with Spoilage of Bakery Products

OpenAIRE

I. A. Adesina; A. O. Ojokoh; D. J. Arotupin

2017-01-01

Aim: To evaluate the potentiality of LAB strains isolated from different fermented products to inhibit moulds associated with spoilage of bakery products. Methodology: Lactic acid bacterial (LAB) strains obtained from fermented products (“burukutu”, “pito”, yoghurt, and “iru”) were screened for antifungal activity against moulds (Aspergillus flavus, Aspergillus fumigatus, Aspergillus repens and Penicillium sp.) isolated from spoilt bakery products. Inhibitory activities of the lactic acid...

Bioactive Compounds Derived from the Yeast Metabolism of Aromatic Amino Acids during Alcoholic Fermentation

Directory of Open Access Journals (Sweden)

Albert Mas

2014-01-01

Full Text Available Metabolites resulting from nitrogen metabolism in yeast are currently found in some fermented beverages such as wine and beer. Their study has recently attracted the attention of researchers. Some metabolites derived from aromatic amino acids are bioactive compounds that can behave as hormones or even mimic their role in humans and may also act as regulators in yeast. Although the metabolic pathways for their formation are well known, the physiological significance is still far from being understood. The understanding of this relevance will be a key element in managing the production of these compounds under controlled conditions, to offer fermented food with specific enrichment in these compounds or even to use the yeast as nutritional complements.

Fisetin yeast-based bio-capsules via osmoporation: effects of process variables on the encapsulation efficiency and internalized fisetin content.

Science.gov (United States)

de Câmara, Antonio Anchieta; Dupont, Sébastien; Beney, Laurent; Gervais, Patrick; Rosenthal, Amauri; Correia, Roberta Targino Pinto; Pedrini, Márcia Regina da Silva

2016-06-01

Osmoporation is an innovative method that can be used with food-grade yeast cells of Saccharomyces cerevisiae as natural encapsulating matrices. This technique overcomes barriers that difficult encapsulation and enables the internalization of fragile bioactive molecules such as fisetin into yeasts. In the present study, we assessed the effects of concentration, osmotic pressure, and temperature on the encapsulation efficiency (EE) and internalized fisetin content (IF). Two different quantification strategies were investigated: direct extraction (DE) without cell washing or freeze-drying steps and indirect extraction (IE) performed after washings with ethanol and freeze-drying. Our results showed that osmoporation improved EE (33 %) and IF (1.199 mg). The best experimental conditions were found by using DE. High-resolution images showed that the yeast cell envelope was preserved during osmoporation at 30 MPa and 84 % of yeast cells remained viable after treatment. Washing cells with organic solvent led to decreased EE (0.65 %) and IF (0.023 mg). This was probably due to either damages caused to yeast cell envelope or fisetin dragged out of cell. Overall, the results demonstrated the adequacy and relevant biotechnological potential of yeasts as encapsulating matrices for hydrophobic compounds. This fresh biotechnological approach has proven to be a promising tool for the production of bioactive-rich food products.

Production of astaxanthin rich feed supplement for animals from Phaffia rhodozyma yeast at low cost

Science.gov (United States)

Irtiza, Ayesha; Shatunova, Svetlana; Glukhareva, Tatiana; Kovaleva, Elena

2017-09-01

Dietary nutrients such as amino acids, vitamins, minerals and antioxidants can play a significant role in determining meat quality and also the growth rate of poultry or animal. Phaffia rhodozyma was grown on waste from brewery industry to produce astaxanthin rich feed supplements at a very low cost. Phaffia rhodozyma is yeast specie that has ability to produce carotenoids and approximately 80% of its total carotenoid content is astaxanthin, which is highly valuable carotenoid for food, feed and aquaculture industry. This study was carried out to test yeast extract of spent yeast from brewing industry waste (residual yeast) as potential nitrogen source for growth of Phaffia rhodozyma. Cultivation was carried out in liquid media prepared by yeast extracts and other components (glucose and peptone). Carotenoids from the biomass were released into biomass by suspending cells in DMSO for destruction of cells followed by extraction with petroleum ether. The extracted carotenoids were studied by spectrophotometry to identify and quantify astaxanthin and other carotenoids produced.

Complete genome sequences of two strains of the meat spoilage bacterium Brochothrix thermosphacta isolated from ground chicken

Science.gov (United States)

Brochothrix thermosphacta is an important meat spoilage bacterium. Here we report the genome sequences of two strains of B. thermosphacta isolated from ground chicken. The genome sequences were determined using long-read PacBio single-molecule real-time (SMRT©) technology and are the first complete ...

Membrane bioreactor wastewater treatment plants reveal diverse yeast and protist communities of potential significance in biofouling.

Science.gov (United States)

Liébana, Raquel; Arregui, Lucía; Belda, Ignacio; Gamella, Luis; Santos, Antonio; Marquina, Domingo; Serrano, Susana

2015-01-01

The yeast community was studied in a municipal full-scale membrane bioreactor wastewater treatment plant (MBR-WWTP). The unexpectedly high diversity of yeasts indicated that the activated sludge formed a suitable environment for them to proliferate, with cellular concentrations of 2.2 ± 0.8 × 10(3) CFU ml(-1). Sixteen species of seven genera were present in the biological reactor, with Ascomycetes being the most prevalent group (93%). Most isolates were able to grow in a synthetic wastewater medium, adhere to polyethylene surfaces, and develop biofilms of variable complexity. The relationship between yeast populations and the protists in the MBR-WWTP was also studied, revealing that some protist species preyed on and ingested yeasts. These results suggest that yeast populations may play a role in the food web of a WWTP and, to some extent, contribute to membrane biofouling in MBR systems.

Quality parameters and RAPD-PCR differentiation of commercial baker's yeast and hybrid strains.

Science.gov (United States)

El-Fiky, Zaki A; Hassan, Gamal M; Emam, Ahmed M

2012-06-01

Baker's yeast, Saccharomyces cerevisiae, is a key component in bread baking. Total of 12 commercial baker's yeast and 2 hybrid strains were compared using traditional quality parameters. Total of 5 strains with high leavening power and the 2 hybrid strains were selected and evaluated for their alpha-amylase, maltase, glucoamylase enzymes, and compared using random amplified polymorphic DNA (RAPD). The results revealed that all selected yeast strains have a low level of alpha-amylase and a high level of maltase and glucoamylase enzymes. Meanwhile, the Egyptian yeast strain (EY) had the highest content of alpha-amylase and maltase enzymes followed by the hybrid YH strain. The EY and YH strains have the highest content of glucoamylase enzyme almost with the same level. The RAPD banding patterns showed a wide variation among commercial yeast and hybrid strains. The closely related Egyptian yeast strains (EY and AL) demonstrated close similarity of their genotypes. The 2 hybrid strains were clustered to Turkish and European strains in 1 group. The authors conclude that the identification of strains and hybrids using RAPD technique was useful in determining their genetic relationship. These results can be useful not only for the basic research, but also for the quality control in baking factories. © 2012 Institute of Food Technologists®

Study of device of electron-ion treatment of mother baking yeasts

International Nuclear Information System (INIS)

Ostapenkov, A.M.; Merinov, N.S.; Nazarov, V.N.; Balan, E.L.

1980-01-01

Devices for electron- ion treatment of mother baking yeasts are considered and classified by the way of aerions removal from the ionization zone: the first ones - by means of the electric field, the other - by air directed flux. Devices of the first type require high voltage - 20-60 kV. Electrodynamic ion generator has been applied as a device of the second type; considered is its construction, principal of operation, given are diagrams of ion flux dependence. The methods of process calculations in the generator and experimental results are presented. The main advantage of the generator of the second type is operation at low (3-5 kV) voltages. It is shown, that the yeast growth module can achieve 36% at essential increase of biomass when using these yeasts as sowing. The device can be used for biostimulation and antisepting of food raw materials

Metal Oxide Nanostructures in Food Applications: Quality Control and Packaging

Directory of Open Access Journals (Sweden)

Vardan Galstyan

2018-04-01

Full Text Available Metal oxide materials have been applied in different fields due to their excellent functional properties. Metal oxides nanostructuration, preparation with the various morphologies, and their coupling with other structures enhance the unique properties of the materials and open new perspectives for their application in the food industry. Chemical gas sensors that are based on semiconducting metal oxide materials can detect the presence of toxins and volatile organic compounds that are produced in food products due to their spoilage and hazardous processes that may take place during the food aging and transportation. Metal oxide nanomaterials can be used in food processing, packaging, and the preservation industry as well. Moreover, the metal oxide-based nanocomposite structures can provide many advantageous features to the final food packaging material, such as antimicrobial activity, enzyme immobilization, oxygen scavenging, mechanical strength, increasing the stability and the shelf life of food, and securing the food against humidity, temperature, and other physiological factors. In this paper, we review the most recent achievements on the synthesis of metal oxide-based nanostructures and their applications in food quality monitoring and active and intelligent packaging.

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...

Cooked meat products made of coarsely ground pork: the main bacterial strains of bacterial flora, their heat resistance and effect on spoilage

Directory of Open Access Journals (Sweden)

Esko Petäjä

1993-09-01

Full Text Available This study was conducted to investigate the bacterial flora of the surface layer and the core of meat products made of coarsely ground pork at the moment of spoilage when stored at 7°C or 4°C. The dominating strains were isolated, their heat resistance was studied in APT-broth, on APT-agar and in coarsely ground cured pork, and their growth after heating and effect on spoilage were followed in coarsely ground cured pork. The first signs of spoilage appeared in the surface layer of the products. The strains were coccoid lactic acid bacteria with counts ranging from 3,5 to 7.8 log cfu (colony forming units/g. They survived only accidentally after heating for 15 minutes at 72°C in APT-broth. The core of the products contained only coccoid lactic acid bacteria or only pseudomonads or both as the main bacterial strains. The counts ranged from 2.6 to 6.0 log cfu/g. Most of the strains isolated from the core survived after heating for 30 minutes at 72°C in APT-broth in at least three tests out of six. The most noticeable result of the study was the occurence of heat-resistant pseudomonads in the core. It must be pointed out that all pseudomonads found survived after heating for 60 minutes at 72°C in APT-broth, and often after heating for 15 minutes at 72°C in coarsely ground cured pork (core 72°C. The cfu number of the two most heat-resistant streptococcus strains decreased only 1 log unit over 15 minutes at 72°C in coarsely ground cured pork. The numbers of inoculated pseudomonads decreased but those of streptococci rose by a maximum of 1 log unit when the experimental porks were kept at 4°C after heating. This indicates that streptococci and pseudomonads probably do not constitute a serious spoilage factor in cooked meat products, but spoilage is generally effected by bacteria which have contaminated the surface layer of the products after heat treatment.

Food irradiation in Romania - Achievements and expectations

International Nuclear Information System (INIS)

Ferdes, O.S.

1993-01-01

Irradiation or ionization of foodstuffs and agricultural products is an efficient but controversial method which can lead to the post-harvest spoilages reduction, the extension of shelf-life and to provide the food safety. This paper presents the status of food irradiation research and technologies in our country, and throughout the world, too. In Romania the food processing by irradiation (ionization) is not used for commercial purposes and there are not food irradiation plants, yet. There have been performed only research and pilot-experiments, only by the Institute of Food Research in co-operation and using the 6 0C o gamma-ray sources of the Institute of Chemical and Pharmaceutical Research and the Institute of Physics and Nuclear Engineering, both from Bucharest. These experiments have referred both to the basic aspects of the ionizing radiation interactions with the food essential constituents and to the technological aspects of irradiation from different items like: potatoes, onions, garlic, grain, cereals, wheat flour, fresh and dehydrated fruits and vegetables, mushrooms, meat, eggs, spices, ingredients, and biotechnological products. There are also presented the advantages and disadvantages of food irradiation, the world trends in this field and the future in Romania of this technology which was named, in 1989, by the Institute of Food Technologies (US), t he most versatile technology of the 20 -th Century, for tomorrow . (Author)

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.

Fatty acids from oleaginous yeasts and yeast-like fungi and their potential applications.

Science.gov (United States)

Xue, Si-Jia; Chi, Zhe; Zhang, Yu; Li, Yan-Feng; Liu, Guang-Lei; Jiang, Hong; Hu, Zhong; Chi, Zhen-Ming

2018-02-01