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Sample records for sangar fresh cut

  1. Factors affecting quality and safety of fresh-cut produce.

    Science.gov (United States)

    Francis, G A; Gallone, A; Nychas, G J; Sofos, J N; Colelli, G; Amodio, M L; Spano, G

    2012-01-01

    The quality of fresh-cut fruit and vegetable products includes a combination of attributes, such as appearance, texture, and flavor, as well as nutritional and safety aspects that determine their value to the consumer. Nutritionally, fruit and vegetables represent a good source of vitamins, minerals, and dietary fiber, and fresh-cut produce satisfies consumer demand for freshly prepared, convenient, healthy food. However, fresh-cut produce deteriorates faster than corresponding intact produce, as a result of damage caused by minimal processing, which accelerates many physiological changes that lead to a reduction in produce quality and shelf-life. The symptoms of produce deterioration include discoloration, increased oxidative browning at cut surfaces, flaccidity as a result of loss of water, and decreased nutritional value. Damaged plant tissues also represent a better substrate for growth of microorganisms, including spoilage microorganisms and foodborne pathogens. The risk of pathogen contamination and growth is one of the main safety concerns associated with fresh-cut produce, as highlighted by the increasing number of produce-linked foodborne outbreaks in recent years. The pathogens of major concern in fresh-cut produce are Listeria monocytogenes, pathogenic Escherichia coli mainly O157:H7, and Salmonella spp. This article describes the quality of fresh-cut produce, factors affecting quality, and various techniques for evaluating quality. In addition, the microbiological safety of fresh-cut produce and factors affecting pathogen survival and growth on fresh-cut produce are discussed in detail.

  2. Systematic Study of the Content of Phytochemicals in Fresh and Fresh-Cut Vegetables

    Directory of Open Access Journals (Sweden)

    María Isabel Alarcón-Flores

    2015-05-01

    Full Text Available Vegetables and fruits have beneficial properties for human health, because of the presence of phytochemicals, but their concentration can fluctuate throughout the year. A systematic study of the phytochemical content in tomato, eggplant, carrot, broccoli and grape (fresh and fresh-cut has been performed at different seasons, using liquid chromatography coupled to triple quadrupole mass spectrometry. It was observed that phenolic acids (the predominant group in carrot, eggplant and tomato were found at higher concentrations in fresh carrot than in fresh-cut carrot. However, in the case of eggplant, they were detected at a higher content in fresh-cut than in fresh samples. Regarding tomato, the differences in the content of phenolic acids between fresh and fresh-cut were lower than in other matrices, except in winter sampling, where this family was detected at the highest concentration in fresh tomato. In grape, the flavonols content (predominant group was higher in fresh grape than in fresh-cut during all samplings. The content of glucosinolates was lower in fresh-cut broccoli than in fresh samples in winter and spring sampling, although this trend changes in summer and autumn. In summary, phytochemical concentration did show significant differences during one-year monitoring, and the families of phytochemicals presented different behaviors depending on the matrix studied.

  3. ANTIOXIDANT ENZYME ACTIVITY AND FRESH-CUT ARRACACHA QUALITY

    Directory of Open Access Journals (Sweden)

    Hêmina Carla Vilela

    2015-06-01

    Full Text Available The arracacha is an alternative of fresh-cut product; however it can be easily degraded after the processing techniques. The objective of this work was to evaluate the useful life of fresh-cut arracacha submitted to two types of cuts and storage, as well as to evaluate the activity of antioxidant enzymes. The roots were selected, sanitized and submitted to two cut types: cubed and grated. Then they were evaluated at 3 times: 0, 3 and 7 days. The cutting in cubes provided higher quality and lower SOD, CAT and APX activity. However, the grated product presented higher PG activity and lower PPO activity. The microbiological safety and the nutritional value were maintained in both cuts during the whole storage period. The useful life, regarding the physicochemical, nutritional and microbiological aspects, can be established at 7 days under refrigeration for fresh-cut arracacha.

  4. Factors affecting the postharvest performance of fresh-cut lettuce

    NARCIS (Netherlands)

    Witkowska, I.M.

    2013-01-01

    The quality of fresh-cut fruits and vegetables is often offset by a rapid deterioration, due to severe physical stress, such as peeling, cutting, slicing, shredding, and trimming. Due to this wounding, the already short shelf-life of these harvested products is even more reduced in the market place.

  5. Incidence of chilling injury in fresh-cut 'Kent' mangoes

    Science.gov (United States)

    The preferred storage temperature for fresh-cut fruits in terms of visual quality retention is around 5 °C, which is considered to be a chilling temperature for chilling sensitive tropical fruits like mango (Mangifera indica L.). Changes in visual and compositional quality factors, aroma volatile pr...

  6. Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

    NARCIS (Netherlands)

    Moreira Lana, M.; Tijskens, L.M.M.; Kooten, van O.

    2005-01-01

    To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5°C. Intact (control) fruits were stored in the same conditions. The antioxidant activity was evalu

  7. Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

    NARCIS (Netherlands)

    Moreira Lana, M.; Tijskens, L.M.M.

    2006-01-01

    To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5 °C. Intact fruits were stored in the same conditions as a control. The antioxidant activity was e

  8. Effects of cutting and maturity on antioxidant activity of fresh-cut tomatoes

    NARCIS (Netherlands)

    Moreira Lana, M.; Tijskens, L.M.M.

    2006-01-01

    To investigate the changes in total antioxidant activity of fresh-cut tomato during storage, tomato fruits harvested at three different stages of maturity were cut into 7-mm thick slices and stored at 5 °C. Intact fruits were stored in the same conditions as a control. The antioxidant activity was e

  9. Cultivar affects browning susceptibility of freshly cut star fruit slices

    Directory of Open Access Journals (Sweden)

    Teixeira Gustavo Henrique de Almeida

    2006-01-01

    Full Text Available Consumption of freshly-cut horticultural products has increased in the last few years. The principal restraint to using freshly-cut carambola is its susceptibility to tissue-browning, due to polyphenol oxidase-mediated oxidation of phenolic compounds present in the tissue. The current study investigated the susceptibility to browning of star fruit slices (Averrhoa carambola L. of seven genotypes (Hart, Golden Star, Taen-ma, Nota-10, Malásia, Arkin, and Fwang Tung. Cultivar susceptibility to browning as measured by luminosity (L* varied significantly among genotypes. Without catechol 0.05 M, little changes occurred on cut surface of any cultivars during 6 hour at 25degreesC, 67% RH. Addition of catechol led to rapid browning, which was more intense in cvs. Taen-ma, Fwang Tung, and Golden Star, with reduction in L* value of 28.60%, 27.68%, and 23.29%, respectively. Browning was more intense in the center of the slices, particularly when treated with catechol, indicating highest polyphenol oxidase (PPO concentration. Epidermal browning, even in absence of catechol, is a limitation to visual acceptability and indicates a necessity for its control during carambola processing. Care must be given to appropriate selection of cultivars for fresh-cut processing, since cultivar varied in browning susceptibility in the presence of catechol.

  10. Edible coatings enriched with essential oils and their compounds for fresh and fresh-cut fruit.

    Science.gov (United States)

    Antunes, Maria D; Gago, Custodia M; Cavaco, Ana M; Miguel, Maria G

    2012-08-01

    Fresh fruit and vegetables consumption has increased in the past few years due to the enhanced awareness of consumers for healthy food. However, these products are highly perishable, and losses can be of great significance if postharvest correct management is not provided. Fresh-cut products are of increasing importance, since they are presented to the consumer in a state that allows for direct and immediate consumption. However, those products are even more perishable since cutting can induce a series of senescence associated responses to wounding, and are more susceptible to microbial spoilage. Edible coatings, which intend to reduce ripening processes and protect the fruit from water loss and spoilage may be a good way to enhance the shelf life of these products. More recently, the inclusion of additives into these edible coatings to increase their effectiveness, such as essential oils and their constituents with antimicrobial and antioxidant activities, has been reported and patented.

  11. Importance of Seed Quality for the Fresh-cut Chain

    DEFF Research Database (Denmark)

    Deleuran, Lise Christina; Olesen, Merete Halkjær; Shetty, Nisha

    2011-01-01

    Seed is the most fundamental input in vegetable production on, which the effectiveness of other inputs and outputs depends. If the seed is of poor quality, the use of other inputs is less successful and will occasionally be irrelevant. A definition of seed quality will depend upon the use for......, which the seed is intended. Viability, vigor, uniformity, purity and health of the seeds are quality parameters important for all production systems. The ideal situation for both fresh produce and fresh cut would be seeds, which germinate uniform at a high percentage and subsequently grow relatively...... fast to the desired size, thus, resulting in leaves of improved quality. It is likely that such leaves will be more able to withstand the rigorous processing that includes harvest, transportation, washing, sanitization, de-watering and packaging. This ideal situation would both be determined...

  12. Effects of fresh Aloe vera gel coating on browning alleviation of fresh cut wax apple (Syzygium samarangenese) fruit cv. Taaptimjaan.

    Science.gov (United States)

    Supapvanich, S; Mitrsang, P; Srinorkham, P; Boonyaritthongchai, P; Wongs-Aree, C

    2016-06-01

    The effect of natural coating by using fresh Aloe vera (A. vera) gel alleviating browning of fresh-cut wax apple fruits cv. Taaptimjaan was investigated. The fresh-cut fruits were dipped in fresh A. vera gel at various concentrations of 0, 25, 75 or 100 % (v/v) for 2 min at 4 ± 1 °C for 6 days. Lightness (L*), whiteness index (WI), browning index (BI), total color difference (ΔE*), sensorial quality attributes, total phenolic (TP) content, antioxidant activity and polyphenol oxidase (PPO) and peroxidase (POD) activities were determined. During storage, L* and WI of the fresh-cut fruits surface decreased whilst their BI and ΔE* increased. A. vera coating maintained the L* and WI and delayed the increase in BI and ΔE*, especially at 75 % A. vera dip. The fresh-cut fruits dipped in 75 % A. vera had the lowest browning score, the highest acceptance score and delayed the increase in TP content and PPO activity. However POD activity was induced by A. vera coating. Antioxidant activity had no effect on browning incidence of the fresh-cut fruits. Consequently, A. vera gel coating could maintain quality and retarded browning of fresh-cut wax apple fruits during storage.

  13. Determination of Phytoestrogen Content in Fresh-Cut Legume Forage

    Directory of Open Access Journals (Sweden)

    Pavlína Hloucalová

    2016-07-01

    Full Text Available The aim of the study was to determine phytoestrogen content in fresh-cut legume forage. This issue has been much discussed in recent years in connection with the health and safety of feedstuffs and thus livestock health. The experiments were carried out on two experimental plots at Troubsko and Vatín, Czech Republic during June and July in 2015. Samples were collected of the four forage legume species perennial red clover (variety “Amos”, alfalfa (variety “Holyně”, and annuals Persian clover and Alexandrian clover. Forage was sampled twice at regular three to four day intervals leading up to harvest and a third time on the day of harvest. Fresh and wilted material was analyzed using liquid chromatography–mass spectrometry (LC-MS. Higher levels ( p < 0.05 of isoflavones biochanin A (3.697 mg·g −1 of dry weight and formononetin (4.315 mg·g −1 of dry weight were found in red clover than in other species. The highest isoflavone content was detected in red clover, reaching 1.001% of dry matter ( p < 0.05, representing a risk for occurrence of reproduction problems and inhibited secretion of animal estrogen. The phytoestrogen content was particularly increased in wilted forage. Significant isoflavone reduction was observed over three to four day intervals leading up to harvest.

  14. Effects of cutting and maturity on lycopene concentration of fresh-cut tomatoes during storage at different temperatures

    NARCIS (Netherlands)

    Moreira Lana, M.; Dekker, M.; Linssen, R.F.A.; Kooten, van O.

    2005-01-01

    To investigate the changes in lycopene concentration of fresh-cut tomato during storage, tomato fruits at different stages of maturity were cut into 7 mm slices and stored at temperatures varying from 2°C to 16°C. To assess the effect of cutting, intact fruit were stored in an additional experiment

  15. Effects of cutting and maturity on lycopene concentration of fresh-cut tomatoes during storage at different temperatures

    NARCIS (Netherlands)

    Moreira Lana, M.; Dekker, M.; Linssen, R.F.A.; Kooten, van O.

    2005-01-01

    To investigate the changes in lycopene concentration of fresh-cut tomato during storage, tomato fruits at different stages of maturity were cut into 7 mm slices and stored at temperatures varying from 2°C to 16°C. To assess the effect of cutting, intact fruit were stored in an additional experiment

  16. Dietitians' attitudes, perceptions, and usage patterns for fresh-cut fruit and vegetables.

    Science.gov (United States)

    Sanford, Katherine A; Johnston, Elizabeth M; Porter, Jennifer L; Lowe, Judith; Oxby, Debra M

    2008-01-01

    New fresh-cut fruit and vegetable products are being developed worldwide. Nutrition educators' perceptions of these products were studied. Professional dietitians in Nova Scotia were asked to complete a questionnaire on their use of fresh-cut produce. The questionnaire also elicited their attitudes and perceptions about the convenience, taste/quality, nutrition/health benefits, cost, and safety of fresh-cut fruit and vegetables. Sixty-three percent of respondents reported eating five to six servings of fruit and vegetables a day. This group most frequently consumed fresh-cut fruit as snacks or dessert, and vegetables in stir-fry dishes or salads or cooked with meals. In general, fresh-cut fruit and vegetables were perceived as convenient, safe, and nutritious. While approximately 50% of participants felt fresh-cut produce did not differ in taste from whole fresh produce, almost the same number considered whole fresh produce superior in taste. Dietitians have a generally positive perception of fresh-cut products; however, there is uncertainty about the nutritional value, cost/benefit, and use of the products. Dietitians require more information on the nutrient value of these products and on suggested alternative uses. Attention should be paid to developing fresh-cut products that have good sensory quality.

  17. Cold plasma as an antimicrobial intervention for fresh and fresh-cut fruits and vegetables: an ERRC research update

    Science.gov (United States)

    Contamination of fresh and fresh-cut fruits and vegetables by foodborne pathogens has prompted research at the Eastern Regional Research Center into novel interventions. Cold plasma is a nonthermal food processing technology which uses energetic, reactive gases to inactivate contaminating microbes. ...

  18. Growth Potential of Listeria Monocytogenes and Staphylococcus Aureus on Fresh-Cut Tropical Fruits.

    Science.gov (United States)

    Feng, Ke; Hu, Wenzhong; Jiang, Aili; Xu, Yongping; Sarengaowa; Li, Xiaobo; Bai, Xue

    2015-11-01

    The objective of this study was to evaluate the fate of Staphylococcus aureus, Listeria monocytogenes, and natural microbiota on fresh-cut tropical fruits (pitaya, mango, papaya and pineapple) with commercial PVC film at different storage temperature (5, 13, and 25 °C). The results showed that S. aureus, L. monocytogenes, and natural microbiota increased significantly on fresh-cut tropical fruits at 25 °C. Both pathogen and natural microbiota were able to grow on fresh-cut tropical fruits at 13 °C. The maximum population of L. monocytogenes was higher than that of S. aureus on fresh-cut tropical fruits. L. monocytogenes and S. aureus could survive without growth on fresh-cut pitaya, mango, and papaya at 5 °C. The population of L. monocytogenes declined significantly on fresh-cut pineapple at all temperature, indicating composition of fresh-cut pineapple could inhibit growth of L. monocytogenes. However, S. aureus was still able to grow on fresh-cut pineapple at storage temperature. Thus, this study suggests that 4 kinds of fresh-cut tropical fruits (pitaya, mango, papaya, and pineapple) should be stored at low temperature to extend shelf life as well as to ensure the safety of fresh-cut fruits. The data collected in this study demonstrated that L. monocytogenes and S. aureus were able to grow on fresh-cut tropical fruits at different temperatures. These results could be of interest in knowing the capacity of tropical fruits to support the growth of L. monocytogenes and S. aureus. This information may also be useful to local and state regulatory officials responsible for food safety.

  19. Modelling RGB colour aspects and translucency of fresh-cut tomatoes

    NARCIS (Netherlands)

    Moreira Lana, M.; Tijskens, L.M.M.; Kooten, van O.

    2006-01-01

    Translucency is one of the major problems in fresh-cut fruit. This phenomenon seriously limits the use of fruit by the fresh-cut industries. Techniques for measuring translucency in this kind of product are not readily available. As a consequence, the processes that are important in the development

  20. Modelling quality of fresh-cut tomato based on stage of maturity and storage conditions

    NARCIS (Netherlands)

    Moreira Lana, M.

    2005-01-01

    Fresh-cut or minimally processed vegetables are those which have been trimmed and/or peeled and/or cut into 100% usable product and still maintain freshness. Contrary to other processing methods (freezing, canning and drying for example) the minimal processing operations reduce the shelf life in rel

  1. Modelling quality of fresh-cut tomato based on stage of maturity and storage conditions

    NARCIS (Netherlands)

    Moreira Lana, M.

    2005-01-01

    Fresh-cut or minimally processed vegetables are those which have been trimmed and/or peeled and/or cut into 100% usable product and still maintain freshness. Contrary to other processing methods (freezing, canning and drying for example) the minimal processing operations reduce the shelf life in rel

  2. Modelling quality of fresh-cut tomato based on stage of maturity and storage conditions

    NARCIS (Netherlands)

    Moreira Lana, M.

    2005-01-01

    Fresh-cut or minimally processed vegetables are those which have been trimmed and/or peeled and/or cut into 100% usable product and still maintain freshness. Contrary to other processing methods (freezing, canning and drying for example) the minimal processing operations reduce the shelf life in

  3. Effect of combined underwater processing and mild pre-cut heat treatment on the sensory quality and storage of fresh-cut cantaloupe melon.

    Science.gov (United States)

    Fresh cut fruit, mildly preheated and processed underwater, was shown to have superior sensory quality attributes compared to the control fresh cut fruit processed totally in open air. Less leakage of ions and enhanced plasma membrane integrity was displayed in both the fresh cut fruit processed un...

  4. Bioremediation of soil contaminated with spent and fresh cutting ...

    African Journals Online (AJOL)

    OLAYONWAOLUWOLE JOHN

    2013-10-16

    Oct 16, 2013 ... hydrocarbons has detrimental effects on ecosystems. As such contaminants ... cuttings containing Polyaromatic Hydrocarbons (PAH's) ... water soluble cutting fluid of varying concentrations (0, 10, 20 and. 30%). A mud ...

  5. Quality changes and nutrient retention in fresh-cut versus whole fruits during storage.

    Science.gov (United States)

    Gil, María I; Aguayo, Encarna; Kader, Adel A

    2006-06-14

    The influences of processing and storage on the quality indices and nutritional content of fresh-cut fruits were evaluated in comparison to whole fruits stored for the same duration but prepared on the day of sampling. Fresh-cut pineapples, mangoes, cantaloupes, watermelons, strawberries, and kiwifruits and whole fruits were stored for up to 9 days in air at 5 degrees C. The postcutting life based on visual appearance was shorter than 6 days for fresh-cut kiwifruit and shorter than 9 days for fresh-cut pineapple, cantaloupe, and strawberry. On the other hand, fresh-cut watermelon and mango pieces were still marketable after 9 days at 5 degrees C. Losses in vitamin C after 6 days at 5 degrees C were fresh-cut fruit products tested after 6 days at 5 degrees C. Light exposure promoted browning in pineapple pieces and decreased vitamin C content in kiwifruit slices. Total carotenoids contents decreased in cantaloupe cubes and kiwifruit slices, but increased in mango and watermelon cubes in response to light exposure during storage at 5 degrees C for up to 9 days. There was no effect of exposure to light on the content of phenolics. In general, fresh-cut fruits visually spoil before any significant nutrient loss occurs.

  6. Effects of cutting and maturity on lycopene concentration of fresh-cut tomatoes during storage at different temperatures

    OpenAIRE

    Moreira Lana, M.; Dekker, M.; Linssen, R.F.A.; Kooten, van, G.C.

    2005-01-01

    To investigate the changes in lycopene concentration of fresh-cut tomato during storage, tomato fruits at different stages of maturity were cut into 7 mm slices and stored at temperatures varying from 2°C to 16°C. To assess the effect of cutting, intact fruit were stored in an additional experiment at 5°C. Cutting did not change the accumulation of lycopene in fruit stored at 5°C, compared to intact fruit. The lycopene concentration of the tomato slices stored at different temperatures showed...

  7. Effect of ripeness stage during processing on Listeria monocytogenes growth on fresh-cut 'Conference' pears.

    Science.gov (United States)

    Colás-Medà, Pilar; Abadias, Maribel; Alegre, Isabel; Usall, Josep; Viñas, Inmaculada

    2015-08-01

    There are several factors that affect the shelf life of fresh-cut fruit, including the cultivar, the ripeness stage of the fruit during processing and the fruit's storage atmosphere and temperature. The effect of fruit ripeness during processing on the survival and growth of Listeria monocytogenes on fresh-cut 'Conference' pear slices at different temperatures (5, 10 and 20 °C) was studied. The four ripeness stages studied in this work (assessed by a fruit's firmness) were mature-green (54-60 N), partially ripe (43-53 N), ripe (31-42 N) and overripe (fresh-cut pear, the growth potential of L. monocytogenes increased with increasing temperature. A pear's ripeness stage during processing is an important consideration to ensure the quality of a fresh-cut pear, but it is not as important for preventing L. monocytogenes growth at common storage temperatures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Pre-Harvest light intensity affects shelf-Life of fresh-cut lettuce

    NARCIS (Netherlands)

    Witkowska, I.M.; Woltering, E.J.

    2010-01-01

    The industry of fresh-cut produce is continuously growing due to increasing demand for fresh, healthy and convenient foods. However, processing of vegetables accelerates quality deterioration due to structural, physiological and biochemical changes. Therefore, the value of the produce to the consume

  9. Potential Application of Ascorbic Acid, Citric Acid and Oxalic Acid for Browning Inhibition in Fresh-Cut Fruits and Vegetables

    OpenAIRE

    Weerayuth SUTTIRAK; Supranee MANURAKCHINAKORN

    2010-01-01

    The market for fresh-cut fruits and vegetables has grown rapidly in recent decades as a result of their freshness, convenience, and human health benefits. However, fresh fruits and vegetables deteriorate very rapidly after processing, especially cut-surface browning resulting from wound-induced physiological and biochemical changes. The application of antibrowning agents is one of the most effective methods for controlling the enzymatic browning reaction in fresh-cut fruits and vegetables. Th...

  10. Impact of mixtures of different fresh-cut fruits on respiration and ethylene production rates.

    Science.gov (United States)

    Mahajan, Pramod V; Luca, Alexandru; Edelenbos, Merete

    2014-07-01

    Packaging and storage of fresh-cut fruits and vegetables are a challenging task, since fresh produce continue to respire and senesce after harvest and processing accelerates the physiological processes. The response on respiration and ethylene production rates of fresh produce to changes in O2 and CO2 concentrations and temperature has been extensively studied for whole fruits but literature is limited on processed and mixed fresh-cut fruits. This study aimed to investigate the effects of mixing various proportions of fresh-cut fruits (melon chunks, apple slices, and pineapples cubes) on respiration and ethylene production rates and to develop predictive models for modified atmosphere packaging. The experiment was designed according to a simplex lattice method and respiration and ethylene production rates were measured at 10 °C. Results showed that single component pineapple cubes, apple slices, and melon chunks, in this order, had significant constant coefficients (P = 0.05) and the greatest impact on respiration rate while the interactive binary and tertiary coefficients were insignificant. For ethylene production rates, single component apple slices, melon chunks, and pineapple cubes, and their 3-component mixtures, in this order, had significant constant coefficients (P = 0.05) while binary coefficients were insignificant. Mathematical models were developed and validated; the cubical model was the best to describe the influence of proportion of fruit on respiration and ethylene production rates, however, considering simplicity the linear part of the model is recommended to quantify respiration and ethylene production rates of mixed fresh-cut fruits. This research helps to quantify the ethylene production and respiration rates of multicomponent mixed fresh-cut fruit, which then can be used for packaging design of fresh-cut produce. © 2014 Institute of Food Technologists®

  11. Biodegradable PLA (polylactic acid) hinged trays keep quality of fresh-cut and cooked spinach.

    Science.gov (United States)

    Botondi, Rinaldo; Bartoloni, Serena; Baccelloni, Simone; Mencarelli, Fabio

    2015-09-01

    This work examines the effects of packaging using two different polymeric trays with hinged lids, polyethylene terephthalate (PET) and polylactic acid (PLA), on fresh-cut and cooked spinach (Spinacia oleracea). Samples were stored in a cold room for 16 days at 4 °C. Chemical (total pigments, total polyphenols, ascorbic acid, antioxidant activity), physical (water activity), technological (colour evaluation), sensorial (aroma, visual appearance and water accumulation) and microbial (total aerobic mesophilic and psychrotrophic counts) parameters were tested. Both polymeric trays maintained the overall quality of fresh spinach for 6 days but spinach stored in PLA trays maintained its flavour longer. A significant increase in total polyphenols, antiradical activity, total carotenoids as well as a decrease in ascorbic acid in fresh spinach was observed in the first 3 days of storage in both samples. Unfortunately, the PLA package accumulated condensed water. The total microbial load of fresh-cut spinach reached about 6.3-7.3 log CFU g(-1) within 8 days. Cooked spinach packed in PLA and PET polymeric hinged trays showed the same behaviour as fresh spinach in terms of quality and shelf life. In conclusion, PLA plastic hinged trays can be used for packaging fresh-cut and cooked cut spinach, but the problem of condensed water must be solved.

  12. Use of Pressure for Improving Storage Quality of Fresh-Cut Produce.

    Science.gov (United States)

    Izumi, Hidemi

    2015-01-01

    The microflora of fresh-cut produce is comprised primarily of phytopathogenic and soilborne organisms, but the product could be contaminated with foodborne pathogens. Populations of bacteria, molds, and yeasts associated with fresh-cut produce decreased to non-detectable levels following a high pressure (HP) treatment of 400 MPa for 10 min at room temperature, except for spore-forming bacteria such as Bacillus spp. which were inactivated when subjected to 600 MPa at 60 °C for 10 min. The HP treatment of 400 MPa for 5-10 min at room temperature for fresh-cut lotus root and pineapple may be commercially feasible as an alternative to chemical sterilization and thermal blanching, respectively. The HP treatment reduced the epiphytic microorganisms of the products to non-detectable levels, and the microbial counts remained at the initial levels during storage at 1 °C with minimal changes in physicochemical and visual quality of the products. However, the HP treatment induced cellular disruption in plant tissue that contributed to the changes in appearance of several fresh-cut vegetables. To improve storage quality, combining lower pressures with complementary technologies should be useful for successful application of HP for other fresh-cut produce.

  13. Alginate- and gellan-based edible films for probiotic coatings on fresh-cut fruits.

    Science.gov (United States)

    Tapia, M S; Rojas-Graü, M A; Rodríguez, F J; Ramírez, J; Carmona, A; Martin-Belloso, O

    2007-05-01

    Alginate- (2% w/v) or gellan-based (0.5%) edible films, containing glycerol (0.6% to 2.0%), N-acetylcysteine (1%), and/or ascorbic acid (1%) and citric acid (1%), were formulated and used to coat fresh-cut apple and papaya cylinders. Water vapor permeability (WVP) was significantly higher (P fresh-cut fruits. Fresh-cut apple and papaya cylinders were successfully coated with 2% (w/v) alginate or gellan film-forming solutions containing viable bifidobacteria. WVP in alginate (6.31 and 5.52 x 10(-9) g m/Pa s m2) or gellan (3.65 and 4.89 x 10(-9) g m/Pa s m2) probiotic coatings of papaya and apple, respectively, were higher than in the corresponding cast films. The gellan coatings and films exhibited better water vapor properties in comparison with the alginate coatings. Values > 10(6) CFU/g B. lactis Bb-12 were maintained for 10 d during refrigerated storage of fresh-cut fruits, demonstrating the feasibility of alginate- and gellan-based edible coatings to carry and support viable probiotics on fresh-cut fruit.

  14. Analytical and Mathematical Determination of Shelf-life of Fresh-cut Red Cabbage

    Directory of Open Access Journals (Sweden)

    Fulya Şimşek

    2017-04-01

    Full Text Available Fresh-cut fruits and vegetables have longer shelf lives when appropriate packaging materials having proper permeability properties are used. For this reason eight different packaging materials having different permeability properties were used and it was aimed to determine the appropriate packaging material and analytical and mathematical shelf lives of fresh cut red cabbage. Head space analysis, microbiological and sensorial analysis together with pH, weight loss (% and colour analysis were performed. As a result of the study, it was determined that low density polyethylene (LDPE film having 20 µm of thickness and 12276 cc/m2-day of oxygen permeability was determined as the most suitable packaging material for packaging of fresh-cut red cabbage. Mathematical microbiological shelf life was determined as 12.33 days and both analytical microbiological and sensorial shelf lives were determined as 12 days. It was shown that Gompertz equation can be used in determination of microbiological shelf life of fresh-cut red cabbage since the analytical and mathematical shelf life results fit to each other. Also, the equation that can be used in calculation of shelf life of fresh-cut red cabbage when packaged with AYPE film having 12276 cc/m2-day oxygen permeability was determined as log(Nt/N0 = 6,83 × exp{-exp{[(0,80*e(6,83-t/6,83]+1}}.

  15. Effect of deastringency treatment of intact persimmon fruits on the quality of fresh-cut persimmons.

    Science.gov (United States)

    Chung, Hun-Sik; Kim, Han-Soo; Lee, Young-Guen; Seong, Jong-Hwan

    2015-01-01

    The changes in the quality characteristics of the fresh-cut products prepared from intact 'Cheongdobansi' persimmons treated with different deastringency methods (nontreated, carbon dioxide gas, warm water, ethanol vapour) have been investigated for 6 days at 10 °C. Flesh firmness of the persimmons decreased after ethanol vapour treatment. The decrease in L(∗) value and flesh firmness in the slices prepared from persimmons treated with warm water was retarded. Soluble solids content and titratable acidity of the persimmons decreased after all deastringency treatments. Soluble tannins and radical scavenging activity of the slices from untreated persimmons were maintained at higher concentrations, unlike slices from astringency-removed persimmons. These results suggest that pre-slicing deastringency treatments affect the characteristics of fresh-cut persimmons, and that warm-water treatment could be a useful method to control the browning and softening of fresh-cut persimmons. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Effect of Storage Temperature on the Quality of Fresh-cut Cattail

    Institute of Scientific and Technical Information of China (English)

    Hesheng HUANG; Haiping WANG; PianPian ZHANG

    2015-01-01

    Fresh-cut cattail was extremely not resistant to store at room temperature. In the first day, it began to etiolate and rot, the fiber content increased, but the vi-tamin C content and reducing sugar content decreased. The aerobic bacterial count increased, the weight loss rate sharply increased, and the sensory quality and food value were gradual y lost. Low temperature storage could decrease the loss of vita-min C and reducing sugar of fresh-cut cattail, reduce the weight loss rate and delay the increase of fiber content, maintain the water and nutrient of fresh-cut cattail, and the storage effect of 0 ℃ was better than 4 ℃.

  17. Photons and electrons: advances in using cold plasma, irradiation, UV and other energy-based treatments for fresh and fresh-cut produce

    Science.gov (United States)

    Conventional antimicrobial treatments for fresh produce rely on chemical compounds and physical contact to inactivate and remove bacterial contamination. Recent research has identified a number of energy-based alternative technologies to improve the safety of fresh and fresh-cut fruits and vegetable...

  18. The membrane may be an important factor in browning of fresh-cut pear.

    Science.gov (United States)

    Li, Zhenghong; Zhang, Yuxing; Ge, Huibo

    2017-09-01

    Surface browning is an important cause of deterioration of fresh-cut fruit during postharvest handling. In this paper, four pear cultivars with different extents of natural browning were selected to analyse the factors involved in browning. The main results are as follows: the lipoxygenase (LOX) activity of 'Mantianhong' and 'Yali' pears was higher accompanied by a stronger degree of browning, while the LOX activity in 'Xueqing' and 'Xinli 7' pears was lower, with less browning. A higher unsaturated fatty acid ratio of pear resulted in reduced browning. The cell membranes disappeared 30min after being cut in 'Mantianhong' pear, which browns easily; however, the cell membranes were still intact 30min after being cut in 'Xueqing' pear, which does not brown easily. Therefore, it can be assumed that the stability of the cell membrane plays an important role in inhibiting browning of fresh-cut pears. Copyright © 2017. Published by Elsevier Ltd.

  19. Potential Application of Ascorbic Acid, Citric Acid and Oxalic Acid for Browning Inhibition in Fresh-Cut Fruits and Vegetables

    Directory of Open Access Journals (Sweden)

    Weerayuth SUTTIRAK

    2010-01-01

    Full Text Available The market for fresh-cut fruits and vegetables has grown rapidly in recent decades as a result of their freshness, convenience, and human health benefits. However, fresh fruits and vegetables deteriorate very rapidly after processing, especially cut-surface browning resulting from wound-induced physiological and biochemical changes. The application of antibrowning agents is one of the most effective methods for controlling the enzymatic browning reaction in fresh-cut fruits and vegetables. This article reviews the use of nature identical antibrowning agents, which are generally recognized as safe (GRAS including ascorbic acid, citric acid and oxalic acid for preventing browning in fresh-cut fruits and vegetables. Factors affecting inhibitory efficiency of the antibrowning agents and synergistic effects of the mixtures in various fresh-cut fruits and vegetables are presented.

  20. 1-Methylcyclopropene effects on temporal changes of aroma volatiles and phytochemicals of fresh-cut cantaloupe

    Science.gov (United States)

    Orange fleshed cantaloupe melons have intense aroma and flavor, but are very perishable. Changes in quality traits were characterized during storage-life of fresh-cut cantaloupe (Cucumis melo var. cantalupensis "Fiesta") cubes treated with 1.0 µL L-1 4 of 1-methylcyclopene for 24 h at 5 ºC, packaged...

  1. Application of Kubelka - Munk analysis to the study of translucency in fresh-cut tomato

    NARCIS (Netherlands)

    Lana, M.M.; Hogenkamp, M.; Koehorst, R.B.M.

    2006-01-01

    In order to assess the development of translucency in fresh-cut tomato (Lycopersicum esculentum cv. Belissimo) during refrigerated storage, two experiments were conducted. In the first one, tomato slices obtained from fruits at breaker and at red stage were stored at 5 ± 0.5 °C and monitored at regu

  2. Acidified sodium chlorite optimisation assessment to improve quality of fresh-cut tatsoi baby leaves.

    Science.gov (United States)

    Tomás-Callejas, Alejandro; López-Velasco, Gabriela; Artés, Francisco; Artés-Hernández, Francisco

    2012-03-15

    The fresh-cut industry commonly uses sodium hypochlorite (NaClO) for disinfection. However, there are certain problems related to its use, and acidified sodium chlorite (ASC) could be an alternative sanitiser to replace it. There is limited research evaluating the effect of ASC on the overall quality of fresh-cut produce, especially sensory quality. In this study the decontamination efficacy and quality attribute effects of ASC on fresh-cut tatsoi after application and during storage were investigated. Tatsoi baby leaves were minimally processed at 8 °C and stored under passive modified atmosphere packaging for up to 11 days at 5 and 10 °C. Low to moderate doses of ASC (100-500 mg L⁻¹) showed an initial antimicrobial efficacy on natural microflora and Escherichia coli as effective as that of NaClO. Regarding contact time, ASC was effective in reducting the E. coli population during the first 30 s of washing, and an increase in contact time did not improve the antimicrobial effect. Sensory quality attributes were well kept for up to 11 days at 5 °C but for only 5 days at the abusive temperature of 10 °C. ASC provides an alternative sanitising technique to NaClO for maintaining the quality and safety of fresh-cut tatsoi baby leaves for up to 11 days at 5 °C. Copyright © 2011 Society of Chemical Industry.

  3. Assessment and speciation of chlorine demand in fresh-cut produce wash water

    Science.gov (United States)

    Production of high quality, fresh-cut produce is a key driver for the produce industry. A critical area of concern is the chlorinated wash water used during post-harvest processing in large industrial processing facilities. Predominantly using a batch process, wash water is recycled over 8hr shift...

  4. Native microflora in fresh-cut processing plants and their potentials of biofilm formation

    Science.gov (United States)

    Representative food contact and non-food contact surfaces in two mid-sized fresh cut processing facilities were sampled for microbiological analyses post routine daily sanitization. Mesophilic and psychrotrophic bacteria on the sampled surfaces were isolated by plating on non-selective bacterial med...

  5. Surface treatments and coatings to maintain fresh cut mango quality in storage

    Science.gov (United States)

    Edible coatings prevent moisture loss and may decrease gas exchange, thereby retaining moisture and flavor of fresh-cut fruit. Previous experiments showed that carboxymethylcellulose (CMC) with added maltodextrin maintained visual quality of stored mango slices also treated with calcium ascorbate an...

  6. Detection of decay in fresh-cut lettuce using hyperspectral imaging and chlorophyll fluorescence imaging

    Science.gov (United States)

    Fresh-cut lettuce sold in modified atmosphere packaging (MAP) is a desirable, but highly perishable product. Decay of tissue can start a few days after processing and may be difficult to detect by quick visual observation. A system for early detection of decay and gradual evaluation of its progress ...

  7. Application of Kubelka - Munk analysis to the study of translucency in fresh-cut tomato

    NARCIS (Netherlands)

    Lana, M.M.; Hogenkamp, M.; Koehorst, R.B.M.

    2006-01-01

    In order to assess the development of translucency in fresh-cut tomato (Lycopersicum esculentum cv. Belissimo) during refrigerated storage, two experiments were conducted. In the first one, tomato slices obtained from fruits at breaker and at red stage were stored at 5 ± 0.5 °C and monitored at regu

  8. Folate content in fresh-cut vegetable packed products by 96-well microtiter plate microbiological assay.

    Science.gov (United States)

    Fajardo, Violeta; Alonso-Aperte, Elena; Varela-Moreiras, Gregorio

    2015-02-15

    Ready-to-eat foods have nowadays become a significant portion of the diet. Accordingly, nutritional composition of these food categories should be well-known, in particular its folate content. However, there is a broad lack of folate data in food composition tables and databases. A total of 21 fresh-cut vegetable and fruit packed products were analysed for total folate (TF) content using a validated method that relies on the folate-dependent growth of chloramphenicol-resistant Lactobacillus casei subspecies rhamnosus (NCIMB 10463). Mean TF content ranged from 10.0 to 140.9μg/100g for the different matrices on a fresh weight basis. Higher TF quantity, 140.9-70.1μg/100g, was found in spinach, rocket, watercress, chard and broccoli. Significant differences were observed between available data for fresh vegetables and fruits from food composition tables or databases and the analysed results for fresh-cut packed products. Supplied data support the potential of folate-rich fresh-cut ready-to-eat vegetables to increase folate intake significantly. Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. Connecting fresh cut chain actors, from seed to produce - a European perspective

    DEFF Research Database (Denmark)

    Deleuran, Lise Christina

    2011-01-01

    structured interviews in the supply chain and the emphasis and choice of seed source in these productions are highlighted. Changes in consumer behavior towards more and more convenience food might further increase consumption of these product formats, however, consumer demand for local and/or organic produce...... raises the need to enhance the supply availability. At present only a very limited assortment of organic fresh-cut products is available for Danish consumers. Without import through commercialized chains, the selection of organic fresh-cut produce would be close to zero....... countries this segment is advanced and the supply chain compartmentalized. Parallels in respect to chain structures are therefore at present mainly drawn from other leafy fresh produce productions. Present approaches for securing year round supply of quality leafy vegetables were identified through...

  10. Growth kinetics of Listeria monocytogenes and spoilage microorganisms in fresh-cut cantaloupe.

    Science.gov (United States)

    Fang, Ting; Liu, Yanhong; Huang, Lihan

    2013-05-01

    The main objective of this study was to investigate the growth kinetics of Listeria monocytogenes and background microorganisms in fresh-cut cantaloupe. Fresh-cut cantaloupe samples, inoculated with three main serotypes (1/2a, 1/2b, and 4b) of L. monocytogenes, were incubated at different temperatures, ranging from 4 to 43 °C, to develop kinetic growth models. During storage studies, the population of both background microorganisms and L. monocytogenes began to increase almost immediately, with little or no lag phase for most growth curves. All growth curves, except for two growth curves of L. monocytogenes 1/2a at 4 °C, developed to full curves (containing exponential and stationary phases), and can be described by a 3-parameter logistic model. There was no significant difference (P = 0.28) in the growth behaviors and the specific growth rates of three different serotypes of L. monocytogenes inoculated to fresh-cut cantaloupe. The effect of temperature on the growth of L. monocytogenes and spoilage microorganisms was evaluated using three secondary models. For L. monocytogenes, the minimum and maximum growth temperatures were estimated by both the Ratkowsky square-root and Cardinal parameter models, and the optimum temperature and the optimum specific growth rate by the Cardinal parameter model. An Arrhenius-type model provided more accurate estimation of the specific growth rate of L. monocytogenes at temperatures <4 °C. The kinetic models developed in this study can be used by regulatory agencies and food processors for conducting risk assessment of L. monocytogenes in fresh-cut cantaloupe, and for estimating the shelf-life of fresh-cut products.

  11. Edible coating as carrier of antimicrobial agents to extend the shelf life of fresh-cut apples

    Science.gov (United States)

    Edible coatings with antimicrobial agents can extend shelf-life of fresh-cut fruits. The effect of lemongrass, oregano oil and vanillin incorporated in apple puree-alginate edible coatings, on shelf-life of fresh-cut 'Fuji' apples, was investigated. Coated apples were packed in air filled polypropyl...

  12. Microbial safety and overall quality of cantaloupe fresh-cut pieces prepared from whole cantaloupe after wet steam treatment

    Science.gov (United States)

    Fresh-cut cantaloupes have been associated with outbreaks of Salmonelosis disease and the minimally processed fresh-cut fruits have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. In this study, we evaluated the effect of minimal wet steam t...

  13. Dual effectiveness of sodium chlorite for enzymatic browning inhibition and Escherichia coli inactivation on fresh-cut apples

    Science.gov (United States)

    This study investigated the dual effectiveness of sodium chlorite (SC) for browning inhibition and microbial inactivation on fresh-cut apples. The SC treatment exhibited a strong inhibition on browning reaction of fresh-cut Red Delicious apples during cold storage. Test results from examination of t...

  14. Application of chlorophyll fluorescence imaging and hyperspectral imaging in evaluation of decay in fresh-cut lettuce

    Science.gov (United States)

    Lettuce (Lactuca sativa L.) is commercially the most popular leafy vegetable whose leaves are usually consumed raw. Cleaned, cored, and chopped (fresh-cut) lettuce is a desirable, but highly perishable product. Modified atmosphere packaging (MAP) has been introduced to maintain quality of fresh-cut ...

  15. Ethanol vapor and saprophytic yeast treatments reduce decay and maintain quality of intact and fresh-cut cherries

    Science.gov (United States)

    The objective of this study was to evaluate the use of an ethanol vapor release pad and a saprophytic yeast (Cryptococcus infirmo-miniatum) to reduce decay and maintain postharvest quality of intact or fresh-cut sweet cherries (Prunus avium L.) cv. Lapins and Bing. Intact or fresh-cut fruit were pac...

  16. Retention of Quality and Nutritional Value of Thirteen Fresh-cut Vegetables Treated with Low Dose Radiation

    Science.gov (United States)

    The recent outbreaks associated with consumption of spinach, lettuce and tomato have resulted in much concern over the safety of fresh-cut vegetables. The industry is in need of a “kill” step to ensure the safety of fresh-cut vegetables. Many studies have demonstrated that a dose of 1 kGy radiatio...

  17. Discrimination methods of biological contamination on fresh-cut lettuce based on VNIR and NIR hyperspectral imaging

    Science.gov (United States)

    Multispectral imaging algorithms were developed using visible-near-infrared (VNIR) and near-infrared (NIR) hyperspectral imaging (HSI) techniques to detect worms on fresh-cut lettuce. The optimal wavebands that detect worm on fresh-cut lettuce for each type of HSI were investigated using the one-way...

  18. Guidelines To Validate Control of Cross-Contamination during Washing of Fresh-Cut Leafy Vegetables.

    Science.gov (United States)

    Gombas, D; Luo, Y; Brennan, J; Shergill, G; Petran, R; Walsh, R; Hau, H; Khurana, K; Zomorodi, B; Rosen, J; Varley, R; Deng, K

    2017-02-01

    The U.S. Food and Drug Administration requires food processors to implement and validate processes that will result in significantly minimizing or preventing the occurrence of hazards that are reasonably foreseeable in food production. During production of fresh-cut leafy vegetables, microbial contamination that may be present on the product can spread throughout the production batch when the product is washed, thus increasing the risk of illnesses. The use of antimicrobials in the wash water is a critical step in preventing such water-mediated cross-contamination; however, many factors can affect antimicrobial efficacy in the production of fresh-cut leafy vegetables, and the procedures for validating this key preventive control have not been articulated. Producers may consider three options for validating antimicrobial washing as a preventive control for cross-contamination. Option 1 involves the use of a surrogate for the microbial hazard and the demonstration that cross-contamination is prevented by the antimicrobial wash. Option 2 involves the use of antimicrobial sensors and the demonstration that a critical antimicrobial level is maintained during worst-case operating conditions. Option 3 validates the placement of the sensors in the processing equipment with the demonstration that a critical antimicrobial level is maintained at all locations, regardless of operating conditions. These validation options developed for fresh-cut leafy vegetables may serve as examples for validating processes that prevent cross-contamination during washing of other fresh produce commodities.

  19. FRUIT JUICES AS AN ALTERNATIVE TECHNIQUE FOR CONSERVATION OF FRESH-CUT BANANA

    Directory of Open Access Journals (Sweden)

    ANDERSON ADRIANO MARTINS MELO

    2014-01-01

    Full Text Available Browning discoloration after cutting is detrimental for the quality of a number of fruits and vegetables, such as banana, apple, pear, potato, and some roots such as cassava, yam, and others. Browning and softening compromise banana after cut shelf-life in a few hours under cold storage. Therefore, anti-browning compounds have been applied to slices before packing. Some commonly used substances are calcium chloride, ascorbic acid, cysteine and citric acid, in immersed inchemical mixtures. Recent studies have demonstrated the possibility of preserving fresh-cut banana immersed in sweetened fruit juice for relatively longer periods, favoring commercialization. This type of conservation, although widely used in Brazil for fruit salads, consists of a more complex system in a physiological basis, requiring adjustment of the solution parameters, such as sugar concentration, pH and acidity, considering the viability and freshness of the plant tissue. In this short review, we discuss some experimental data and present a new method for preserving fresh-cut banana. Reduction of enzymatic activity, either in temporary dipping treatment or permanent immersion of banana slices is regarded as a key factor for maintaining its quality during cold storage.

  20. Formation of trichloromethane in chlorinated water and fresh-cut produce and as a result of reacting with citric acid

    Science.gov (United States)

    Chlorine (sodium hypochlorite) is commonly used by the fresh produce industry to sanitize wash water, fresh and fresh-cut fruits and vegetables. However, possible formation of harmful chlorine by-products is a concern. The objectives of this study were to compare chlorine and chlorine dioxide in t...

  1. Microbial safety and overall quality of cantaloupe fresh-cut pieces prepared from whole fruit after wet steam treatment.

    Science.gov (United States)

    Ukuku, Dike O; Geveke, David J; Chau, Lee; Niemira, Brendan A

    2016-08-16

    Fresh-cut cantaloupes have been associated with outbreaks of Salmonellosis. Minimally processed fresh-cut fruits have a limited shelf life because of deterioration caused by spoilage microflora and physiological processes. The objectives of this study were to use a wet steam process to 1) reduce indigenous spoilage microflora and inoculated populations of Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes on the surface of cantaloupes, and 2) reduce the populations counts in cantaloupe fresh-cut pieces after rind removal and cutting. The average inocula of Salmonella, E. coli O157:H7 and Listeria monocytogenes was 10(7)CFU/ml and the populations recovered on the cantaloupe rind surfaces after inoculation averaged 4.5, 4.8 and 4.1logCFU/cm(2), respectively. Whole cantaloupes were treated with a wet steam processing unit for 180s, and the treated melons were stored at 5°C for 29days. Bacterial populations in fresh-cut pieces prepared from treated and control samples stored at 5 and 10°C for up to 12days were determined and changes in color (CIE L*, a*, and b*) due to treatments were measured during storage. Presence and growth of aerobic mesophilic bacteria and Salmonella, E. coli O157:H7 and L. monocytogenes were determined in fresh-cut cantaloupe samples. There were no visual signs of physical damage on all treated cantaloupe surfaces immediately after treatments and during storage. All fresh-cut pieces from treated cantaloupes rind surfaces were negative for bacterial pathogens even after an enrichment process. Steam treatment significantly (psteam treatment of cantaloupes rind surfaces designated for fresh-cut preparation will enhance the microbial safety of fresh-cut pieces, by reducing total bacterial populations. This process holds the potential to significantly reduce the incidence of foodborne illness associated with fresh-cut fruits.

  2. Sensory characteristics and consumer acceptance and purchase intention toward fresh-cut potatoes.

    Science.gov (United States)

    Montouto-Graña, Mónica; Cabanas-Arias, Sonia; Porto-Fojo, Silvia; Vázquez-Odériz, Ma Lourdes; Romero-Rodríguez, Ma Angeles

    2012-01-01

    For a new product to succeed in the market, it must be accepted by consumers. This study investigates consumer opinions on fresh-cut potatoes packaged under vacuum and under a modified atmosphere using home use tests. The data obtained were related to demographic characteristics and patterns of consumption and to purchase intention toward potatoes and other vegetables. The sensory characteristics evaluated by a panel of assessors trained in the sensory evaluation of potato were also considered. The results indicate that although both products were accepted by the consumer, vacuum-packed potatoes received slightly higher ratings and more consumers intended to purchase this product. The fresh-cut potato packaged under vacuum is a product with all the sensory characteristics that will be accepted by the consumers. The adaptation to the productive process at the industrial level, it can be performed with enough guarantees that the product will definitely be purchased by the consumers. © 2011 Institute of Food Technologists®

  3. Fresh-cut pineapple as a new carrier of probiotic lactic acid bacteria.

    Science.gov (United States)

    Russo, Pasquale; de Chiara, Maria Lucia Valeria; Vernile, Anna; Amodio, Maria Luisa; Arena, Mattia Pia; Capozzi, Vittorio; Massa, Salvatore; Spano, Giuseppe

    2014-01-01

    Due to the increasing interest for healthy foods, the feasibility of using fresh-cut fruits to vehicle probiotic microorganisms is arising scientific interest. With this aim, the survival of probiotic lactic acid bacteria, belonging to Lactobacillus plantarum and Lactobacillus fermentum species, was monitored on artificially inoculated pineapple pieces throughout storage. The main nutritional, physicochemical, and sensorial parameters of minimally processed pineapples were monitored. Finally, probiotic Lactobacillus were further investigated for their antagonistic effect against Listeria monocytogenes and Escherichia coli O157:H7 on pineapple plugs. Our results show that at eight days of storage, the concentration of L. plantarum and L. fermentum on pineapples pieces ranged between 7.3 and 6.3 log cfu g(-1), respectively, without affecting the final quality of the fresh-cut pineapple. The antagonistic assays indicated that L. plantarum was able to inhibit the growth of both pathogens, while L. fermentum was effective only against L. monocytogenes. This study suggests that both L. plantarum and L. fermentum could be successfully applied during processing of fresh-cut pineapples, contributing at the same time to inducing a protective effect against relevant foodborne pathogens.

  4. Effect of carrot puree edible films on quality preservation of fresh-cut carrots

    Directory of Open Access Journals (Sweden)

    Wang X.

    2015-06-01

    Full Text Available The effect of edible films based on carrot puree, chitosan, corn starch, gelatin, glycerol and cinnamaldehyde on fresh-cut carrots was studied during storage. Several parameters, such as firmness, colour, weight loss, total carotenoids, total phenols, polyphenol oxidase (PPO activity and peroxidase (POD activity in coated carrots were determined at regular intervals and then compared with the uncoated carrots throughout the storage period. Significant and expected changes were observed in all carrot samples that were compared. The coating treatment significantly (P < 0.05 delayed the senescence, reduced the deterioration of exterior quality and retained total carotenoids well compared with control (P < 0.05. In addition, significant inhibition of PPO activity (P < 0.05 and POD activity (P < 0.05 as well as reduced accumulation of polyphenols (P < 0.05 were observed for all coated samples. All of these favourable responses induced by coating treatment on minimally processed fresh-cut carrots showed beneficial physiological effects, which would give some useful references to the fresh-cut fruit and vegetable processing industry and satisfy people’s requirements allowing for extending product shelf life without negatively affecting the sensory quality or acceptability.

  5. Identification of innovative potential quality markers in rocket and melon fresh-cut produce.

    Science.gov (United States)

    Cavaiuolo, Marina; Cocetta, Giacomo; Bulgari, Roberta; Spinardi, Anna; Ferrante, Antonio

    2015-12-01

    Ready-to-eat fresh cut produce are exposed to pre- and postharvest abiotic stresses during the production chain. Our work aimed to identify stress responsive genes as new molecular markers of quality that can be widely applied to leaves and fruits and easily determined at any stage of the production chain. Stress responsive genes associated with quality losses were isolated in rocket and melon fresh-cut produce and their expression levels analyzed by quantitative real time PCR (qRT-PCR) at different time points after harvest at 20 °C and 4 °C. qRT-PCR results were supported by correlation analysis with physiological and biochemical determinations evaluated at the same conditions such as chlorophyll a fluorescence indices, total, reducing sugars, sucrose, ethylene, ascorbic acid, lipid peroxidation and reactive oxygen species. In both species the putative molecular markers increased their expression soon after harvest suggesting a possible use as novel and objective quality markers of fresh-cut produces.

  6. Efficacy of sodium hypochlorite and acidified sodium chlorite in preventing browning and microbial growth on fresh-cut produce.

    Science.gov (United States)

    Sun, Shih Hui; Kim, Su Jin; Kwak, Soo Jin; Yoon, Ki Sun

    2012-09-01

    The use of suitable sanitizers can increase the quality of fresh-cut produce and reduce the risk of foodborne illnesses. The objective of this study was to compare the washing effects of 100 mg/L sodium hypochlorite (SH) and 500 mg/L acidified sodium chlorite (ASC) on the prevention of enzymatic browning and the growth of microbial populations, including aerobic plate counts, E. coli, and coliforms, throughout storage at 4°C and 10°C. Fresh-cut zucchini, cucumbers, green bell peppers, and root vegetables such as potatoes, sweet potatoes, carrots, and radishes were used. Compared to SH washing, ASC washing significantly (p<0.05) reduced microbial contamination on the fresh-cut produce and prevented browning of fresh-cut potatoes and sweet potatoes during storage. More effective inhibition of aerobic plate counts and coliforms growth was observed on fresh-cut produce treated with ASC during storage at 10°C. Polyphenol oxidase (PPO) activity of fresh-cut potatoes and sweet potatoes was more effectively inhibited after washing with ASC. The use of 500 mg/L ASC can provide effective antimicrobial and anti-browning treatments of fresh-cut produce, including processed root vegetables.

  7. Effects of postharvest curing treatment on flesh colour and phenolic metabolism in fresh-cut potato products.

    Science.gov (United States)

    Wang, Qingguo; Cao, Yu; Zhou, Lili; Jiang, Cai-Zhong; Feng, Yanyan; Wei, Shaochong

    2015-02-15

    The flesh colour and phenolic metabolism in potato tuber during curing and after cut were investigated. Result indicated that postharvest curing not only changed phenolic metabolism during curing, but also improved fresh-cut colour for 12 days after fresh cut. Significantly lower PAL and higher phenolic content and PPO activities during curing treatment and fresh-cut potatoes were detected compared to the control, which lead to the lower browning in the slices from curing treated potatoes. HPLC analysis revealed that amounts of total phenolics, chlorogenic acid, gallic acid and protocatechuic acid were induced by curing and highly accumulated in the curing treated potatoes. Our results demonstrated that phenolic metabolism played an important role in the control of browning of fresh cut potato after curing.

  8. Surface treatments and coatings to maintain fresh-cut mango quality in storage.

    Science.gov (United States)

    Plotto, Anne; Narciso, Jan A; Rattanapanone, Nithiya; Baldwin, Elizabeth A

    2010-10-01

    Edible coatings may extend fresh-cut fruit storage by preventing moisture loss and decreasing gas exchange. This study evaluated the effect of an antibrowning dip (calcium ascorbate, citric acid and N-acetyl-L-cysteine), followed or not with carboxymethylcellulose (CMC) or carrageenan coatings on quality of fresh-cut mangoes stored at 5 °C for up to 20 days. A fourth treatment, only used in one of four experiments, consisted of chitosan. Treatments were applied on 'Tommy Atkins', 'Kent' and 'Keitt' mangoes harvested from Homestead (FL), and on imported store-bought mangoes. The antibrowning dips maintained the best visual quality during storage for all cultivars, as indicated by higher b*, hue and L*. The CMC coating maintained similar visual quality, but carrageenan or chitosan decreased L* and b*. The antibrowning dip containing calcium ascorbate reduced firmness loss on cut pieces of 'Keitt', 'Kent' and store-bought mangoes. The antibrowning treatment maintained higher titratable acidity for 'Kent' and 'Keitt', resulting in lower sensory sweetness. This study with repeated experiments showed that calcium ascorbate with citric acid and N-acetyl-L-cysteine maintained cut mango slices attractiveness in storage by keeping light color in both varieties. The addition of a polysaccharide coating did not consistently improve quality.

  9. Changes in Ascorbic Acid Content, Antioxidant Capacity and Sensory Quality of Fresh-cut Mangosteens During Storage

    Directory of Open Access Journals (Sweden)

    Supranee MANURAKCHINAKORN

    2004-06-01

    Full Text Available Fresh-cut mangosteens, stored in modified atmosphere packaging (MAP; 5% O2 + 9% CO2, in vacuum packaging (VAC and in air (AIR were examined for ascorbic acid content, antioxidant capacity and sensory quality during 14 days of storage at 4oC. After 4 days-storage, fresh-cut fruits with MAP resulted in better retention of ascorbic acid and antioxidant capacity than those stored in AIR throughout the storage. Furthermore, there were no significant differences in ascorbic acid contents between fruits stored in MAP and VAC, as well as antioxidant capacities, during the remaining period of storage. Fresh-cut fruits with MAP treatment obtained the highest sensory scores, compared with other treatments, throughout the entire period of storage. Fresh-cut mangosteens stored in MAP resulted in the best overall retention of ascorbic acid, antioxidant capacity and sensory quality.

  10. Antioxidant enrichment and antimicrobial protection of fresh-cut fruits using their own byproducts: looking for integral exploitation.

    Science.gov (United States)

    Ayala-Zavala, J F; Rosas-Domínguez, C; Vega-Vega, V; González-Aguilar, G A

    2010-10-01

    Fresh-cut fruit consumption is increasing due to the rising public demand for convenience and awareness of fresh-cut fruit's health benefits. The entire tissue of fruits and vegetables is rich in bioactive compounds, such as phenolic compounds, carotenoids, and vitamins. The fresh-cut fruit industry deals with the perishable character of its products and the large percentage of byproducts, such as peels, seeds, and unused flesh that are generated by different steps of the industrial process. In most cases, the wasted byproducts can present similar or even higher contents of antioxidant and antimicrobial compounds than the final produce can. In this context, this hypothesis article finds that the antioxidant enrichment and antimicrobial protection of fresh-cut fruits, provided by the fruit's own byproducts, could be possible.

  11. Examination of Bacteriophage as a Biocontrol Method for Salmonella on Fresh-Cut Fruit: A Model Study

    National Research Council Canada - National Science Library

    Leverentz B; Conway W.S; Alavidze Z; Janisiewicz W.J; Fuchs Y; Camp M.J; Chighladze E; Sulakvelidze A

    2001-01-01

    .... However, fresh-cut fruits and vegetables may represent an increased food safety concern because of the absence or damage of peel and rind, which normally help reduce colonization of uncut produce...

  12. Quality Attributes of Fresh-Cut Coconut after Supercritical Carbon Dioxide Pasteurization

    Directory of Open Access Journals (Sweden)

    Giovanna Ferrentino

    2013-01-01

    Full Text Available The impact of supercritical CO2 (SC-CO2 process on the quality attributes of fresh-cut coconut has been investigated to establish the acceptability of SC-CO2 treated products by the consumers. Two process conditions, previously identified as optimal to reduce the microbial content of the product, were studied: 12 MPa, 40°C, 30 min and 12 MPa, 45°C, 15 min. The results highlighted that both conditions induced some effects on product attributes. After 30 min of treatment at 12 MPa and 40°C a decrease of lightness (8%, pH (13%, fat content (24%, total phenol content (29%, flavonoid compounds (49%, antioxidant capacity (30% and an increase of dry matter (11% and titratable acidity (51.1% were observed while polyphenol oxidase (PPO exhibited 35% and 98.5% inactivation. Peroxidase enzyme activity increased by 77.8% and 30.4% at 12 MPa, 40°C, 30 min and 12 MPa, 45°C, 15 min, respectively. Sensory evaluations revealed no significant differences in appearance, texture, taste, and aroma of treated fresh-cut coconut compared to the untreated. The study confirms the feasibility of SC-CO2 process for the pasteurization of fresh fruits with a firm structure and opens the door to the possibility of exploiting such a technology at industrial level.

  13. Application of heat treatment, edible coating and chemical dip as barriers to the conservation of fresh-cut vegetables

    OpenAIRE

    Escobar Hernández, Alejandro; Márquez Cardozo, Carlos Julio; Restrepo Flores, Claudia Estela; Cano Salazar, Jaime Andrés; Patiño Gómez, Jairo Humberto

    2014-01-01

    The fresh-cut vegetables consumption is increasing in the worldwide since its foray in the early 90s. The international association of fresh cut products, reported sales in 2000 of 12 billion dollars. The interest in feed quickly and healthy, has stimulated the development of vegetable fourth range, however their high metabolic activity reduces its stability and shelf life. It has promoted the adoption of technologies for minimally processed products that give them longer life and ensure the ...

  14. Alternative sanitizers to chlorine for use on fresh-cut "Galia" (Cucumis melo var. catalupensis) melon.

    Science.gov (United States)

    Silveira, A C; Conesa, A; Aguayo, E; Artes, F

    2008-11-01

    Chlorine is commonly used to reduce microbial load in fresh-cut vegetables. However, the production of chlorinated organic compounds, such as trihalomethanes, which are potential carcinogens, has created the need to investigate the efficiency of nontraditional sanitizers and alternative techniques. The effects of 4 novel sanitizers were tested in fresh-cut "Galia" melon: chlorine dioxide (ClO(2)) at 3 mg/L, peracetic acid (PAA) at 80 mg/L, hydrogen peroxide (H(2)O(2)) at 50 mg/L, and nisin at 250 mg/L plus EDTA 100 mg/L (nisin + EDTA). A chlorine treatment (NaOCl at 150 mg/L) was used as a control. Pieces of melon were packed in polypropylene trays under passive modified atmosphere (3 to 4 kPa of O(2) and 10 to 11 kPa of CO(2)) and stored up to 10 d at 5 degrees C. Microbial growth, firmness, respiration rate, gas composition, sensory evaluation, color, total soluble solids (TSS), and tritable acidity (TA) were evaluated at days 0, 7, and 10. The novel sanitizers PAA, H(2)O(2), and nisin + EDTA, in the studied concentrations, reduced the microbial growth to a more efficient range than chlorine and ClO(2). In addition, those sanitizers delayed softness, did not affect the respiration rate, SST, or AT. The sensorial parameters were kept above the upper limit of marketability and they did not impart an "off flavor." These sanitizers maintained quality and shelf life of fresh-cut Galia melon for 10 d of storage at 5 degrees C. Nevertheless, other concentrations, in particular for ClO(2,) could be tested to study an extended shelf life in melon pieces.

  15. Effect of Different Sanitizers on Microbial, Sensory and Nutritional Quality of Fresh-Cut Jalapeno Peppers

    Directory of Open Access Journals (Sweden)

    Saul Ruiz-Cruz

    2010-01-01

    Full Text Available Problem statement: Sanitation is a critical step to insure safety of fresh-cut produce. The inadequacies of chlorine, currently used as a sanitizer, have stimulated interest in finding safer, more effective sanitizers, however little is known on the impact of these novel sanitizers on sensory and nutrimental quality of the treated products. Approach: The effect of four sanitizers: Sodium hypochlorite (OCl, Peroxiacetic Acid (PA, Acidified Sodium Chlorite (ASC and carvacrol on microbiological, sensorial and nutritional quality (total phenols, vitamin C and antioxidant capacity of fresh-cut jalapeno peppers stored at 5°C during 27 days was evaluated. Results: All sanitizers (except carvacrol maintained microbiological and overall quality of jalapeno peppers during 27 days. ASC (500 and 250 mg L-1 maintained the best microbiological and sensorial properties at the end of the storage period. Carvacrol, active ingredient of oregano essential oil, maintained shelf life for only 17 days. At the end of the storage period, all treatments showed a decrease of 12-43% respect to the initial vitamin C values. Total phenols and antioxidant capacity decreased in a lesser degree. None of the treatments except ACS 500 mg L-1, induced higher losses of vitamin C, total phenols or antioxidant capacity compared to control. Conclusion: Our results showed that all sanitizers were capable of controlling microbial growth without inducing major loss of antioxidant capacity and photochemical. Carvacrol was the only sanitizer that reduced sensory acceptability of fresh-cut jalapeno peppers, however carvacrol treated samples retained the highest levels of photochemical and antioxidant capacity. ASC was the most effective sanitizer even though it was used at concentrations lower that those currently approved by the FDA.

  16. In vitro rumen simulated (RUSITEC) metabolism of freshly cut or wilted grasses with contrasting polyphenol oxidase activities

    OpenAIRE

    2011-01-01

    The study investigated in vitro simulated rumen metabolism of freshly cut and wilted cocksfoot [Dactylis glomerata; high polyphenol oxidase (PPO)] and tall fescue (Festuca arundinacea; low PPO). A 16-vessel RUSITEC was used with the four treatment combinations: cocksfoot wilted (C(w)); cocksfoot fresh (C(f)); tall fescue wilted (TF(w)) and tall fescue fresh (TF(f)). Rumen liquor was collected from four fistulated dairy cows maintained on permanent pasture. The experiment ran for 12 d with sam...

  17. Biodegradable packaging and edible coating for fresh-cut fruits and vegetables

    Directory of Open Access Journals (Sweden)

    Fernanda Galgano

    2015-03-01

    Full Text Available This work focuses on biodegradable packaging and edible coatings applied to fresh-cut fruits and vegetables and their effects on the product quality. Practical applications are mainly limited to the use of biodegradable materials that, however, do not allow full control of the product moisture loss. Better results can be achieved by the combined use of biodegradable packagings with edible coatings and recent research has shown that enrichment with silver montmorillonite nanoparticles may be a promising technique. However, the actual utilization of these materials is still limited, due to the high costs of the raw materials and the limited production.

  18. Capillary gas chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco

    Institute of Scientific and Technical Information of China (English)

    LIU Hong-cheng; LI Qi-wan; TANG Li-bin

    2007-01-01

    Simple procedures for extraction and chromatographic determination of dimethachlon residues in fresh tobacco leaves and cut-tobacco are described. The determination was carried out by capillary gas chromatography (GC) with electron capture detection (ECD) and confirmed by GC-MS. The mean recoveries and relative standard deviation (RSD) were 93.2%~112.9% and 3.5%~6.7%, respectively at levels ranging from 0.01 to 0.1 mg/kg. The limit of determination was 0.001 mg/kg. Tobacco samples in routine check were successfully analyzed using the proposed method.

  19. Effect of hot water surface pasteurization of whole fruit on shelf life and quality of fresh-cut cantaloupe.

    Science.gov (United States)

    Fan, X; Annous, B A; Beaulieu, J C; Sites, J E

    2008-04-01

    Cantaloupes are associated with recent outbreaks of foodborne illnesses and recalls. Therefore, new approaches are needed for sanitization of whole and cut fruit. In the present study, whole cantaloupes were submerged into water in the following 3 conditions: 10 degrees C water for 20 min (control), 20 ppm chlorine at 10 degrees C for 20 min, and 76 degrees C water for 3 min. Populations of microflora were measured on the rinds of the whole cantaloupes. Quality and microbial populations of fresh-cut cantaloupes prepared from whole fruit were analyzed after 1, 6, 8, 10, 13, 16, and 20 d of storage at 4 degrees C. The hot water significantly reduced both total plate count (TPC) and yeast and mold count on rind of whole fruits while chlorine or cold water wash did not result in a significant reduction of microbial population. Fresh-cut pieces prepared from hot water-treated cantaloupes had lower TPC than the other 2 treatments in the later storage periods (days 13 to 20) in 2 of 3 trials. The hot water treatment of whole fruits was inconsistent in reducing yeast and mold count of fresh-cut pieces. Soluble solids content, ascorbic acid content, fluid loss, and aroma and appearance scores were not consistently affected by either hot water or chlorine treatment. Our results suggested that hot water pasteurization of whole cantaloupes frequently resulted in lower TPCs of fresh-cut fruit during storage and did not negatively affect quality of fresh-cut cantaloupes.

  20. Antimicrobial and aromatic edible coating on fresh-cut pineapple preservation

    Directory of Open Access Journals (Sweden)

    Raphaela Gabri Bitencourt

    2014-06-01

    Full Text Available The present research aimed to develop an edible coating incorporated with mint essential oil, evaluate its effectiveness in inhibiting in vitro microbial development, and improve both quality and shelf-life of fresh-cut pineapple. Mint essential oil-containing edible coatings showed in vitro antimicrobial efficiency against Escherichia coli and Salmonella Enteritidis. Titratable acidity, pH, and texture were not affected (P>0.05 by coating or storage time. Mass loss was not higher than 1.0% after the 6th day of storage. No effect of storage time and coating on total soluble solids was observed. Mint essential oil-containing coatings inhibited the growth of yeasts and molds in fresh-cut pineapple. Compared to uncoated and control-coated samples, mint essential oil-containing coatings lessened psychrotrophic bacteria counts throughout storage. Counts of thermotolerant coliforms were not higher than 3.0MPN·g-1 in all treatments, whereas no Salmonella sp. was detected during the 6-day storage. Mint essential oil provided a strong flavor to the fruit, as shown by sensory evaluations.

  1. Volatile profile and physical, chemical, and biochemical changes in fresh cut watermelon during storage

    Directory of Open Access Journals (Sweden)

    Andréa Luiza Ramos Pereira Xisto

    2012-03-01

    Full Text Available Existing data about the aroma of fresh-cut watermelon and the metabolic changes that occur with minimal processing are scarce. Given the close relationship that exists between aroma, texture, and quality characteristics, it is necessary to investigate the changes in the volatile profile and texture of watermelon, a fruit extensively sold in supermarket chains throughout Brazil. The objective of this work was to analyze the volatile profile using solid phase microextraction (SPME as well as texture changes in fresh-cut watermelon stored at 5 °C for ten days. Chromatography associated with sensory analysis (sniffing led us to conclude that 9-carbon (C9 alcohols and aldehydes are the major responsible for the flavor and aroma of minimally processed watermelon stored at 5 ± 1 °C/90 ± 5% RH for ten days, and also that the aroma diminishes in intensity with storage, but it does not affect the final quality of the product. It was noted that the amount of drained liquid, soluble pectin, and weight loss increased during storage concurrently with a reduction in firmness and a structural breakdown of the cells. Pectin methyl esterase activity remained constant and polygalacturonase activity was not detected.

  2. Physicochemical, microbial and sensory quality of fresh-cut red beetroots in relation to sanization method and storage duration

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    Dulal Chandra

    2015-06-01

    Full Text Available Effects of sanitization and storage on fresh-cut beetroots (Beta vulgaris L. were evaluated following sanitation – peeling - cutting (SPC, peeling – sanitation – cutting (PSC and peeling – cutting – sanitation (PCS methods with (Cl, or without (TW, 100 ppm chlorine solution, then packaged in polyethylene bag and stored at 5°C for up to 14 days. Chroma values of fresh-cut beetroots significantly declined whereas whiteness index and titratable acidity values increased, however, texture and total soluble solid contents showed no significant variation. Betalain contents decreased gradually and total phenol content showed inconsistence trend. PCS-Cl treated samples accounted for higher betalains decline and received lower visual quality scores despite its lower total aerobic bacterial count. Minimum microbial population was observed in PSC-Cl methodsalong with higher levels of betalain contents. Considering pigment retention, microbial and visual qualities, beetroots sanitized with chlorine water following PSC method was the best processingway for fresh-cut beetroots and therefore, PSC-Cl treatment could commercially be used for processing of fresh-cut beetroots.

  3. Control of foodborne pathogens on fresh-cut fruit by a novel strain of Pseudomonas graminis.

    Science.gov (United States)

    Alegre, Isabel; Viñas, Inmaculada; Usall, Josep; Teixidó, Neus; Figge, Marian J; Abadias, Maribel

    2013-06-01

    The consumption of fresh-cut fruit has substantially risen over the last few years, leading to an increase in the number of outbreaks associated with fruit. Moreover, consumers are currently demanding wholesome, fresh-like, safe foods without added chemicals. As a response, the aim of this study was to determine if the naturally occurring microorganisms on fruit are "competitive with" or "antagonistic to" potentially encountered pathogens. Of the 97 and 107 isolates tested by co-inoculation with Escherichia coli O157:H7, Salmonella and Listeria innocua on fresh-cut apple and peach, respectively, and stored at 20 °C, seven showed a strong antagonistic capacity (more than 1-log unit reduction). One of the isolates, CPA-7, achieved the best reduction values (from 2.8 to 5.9-log units) and was the only isolate able to inhibit E. coli O157:H7 at refrigeration temperatures on both fruits. Therefore, CPA-7 was selected for further assays. Dose-response assays showed that CPA-7 should be present in at least the same amount as the pathogen to adequately reduce the numbers of the pathogen. From the results obtained in in vitro assays, competition seemed to be CPA-7's mode of action against E. coli O157:H7. The CPA-7 strain was identified as Pseudomonas graminis. Thus, the results support the potential use of CPA-7 as a bioprotective agent against foodborne pathogens in minimally processed fruit. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Biochemical and color changes of fresh-cut melon (Cucumis melo L. cv. Galia treated with UV-C

    Directory of Open Access Journals (Sweden)

    Rezzan Kasim

    2014-09-01

    Full Text Available The importance of minimally processed commodities in the retail groceries of most developed countries has been rising continuously during the last decades. Cantaloupe melon is used more than any other fruit in fresh-cut processing. Ultraviolet (UV light has been extensively used to simulate biological stres in plants and for determining resistance mechanisms of plant tissues. In this study the effect of ultraviolet irradiation on some properties of fresh-cut cantalope melon was determined during storage. Freshly cut cantalope melons cubes treated with ultraviolet irradiation at the doses of 1, 2 or 3 min before storage, and then placed in a cold room at 5±1°C temperature and 85-90% RH. Hue angle values of control group is low compared to UV-C treated samples, whereas L values of is high. EL of UV treated samples higher than those of control group. Total soluble solids of fresh-cut melon samples in UC3 treatment increased during storage. The results indicate that UV-C treatments on fresh-cut cantaloupe melon cubes increased total soluble solids independently from water loss.

  5. Using antibrowning agents to enhance quality and safety of fresh-cut avocado treated with intense light pulses.

    Science.gov (United States)

    Ramos-Villarroel, Ana Y; Martín-Belloso, Olga; Soliva-Fortuny, Robert

    2011-01-01

    The effect of antibrowning compounds on the color and firmness of fresh-cut avocado treated with intense light pulses (ILP), as well as their impact on the survival of Listeria innocua, was investigated in this study. Dipping solutions containing 2% (w/v) L-cysteine without ascorbic acid and combined with 1% (w/v) citric acid and 1% w/v calcium lactate most effectively preserved the initial color and texture of ILP-treated fresh-cut avocado. On the other hand, ILP treatments caused a reduction of more than 3 log cycles in the populations of L. innocua inoculated on fresh-cut avocado. Log reduction levels increased when antibrowning agents were combined with ILP treatments. In conclusion, the use of quality-stabilizing agents is a good option to guarantee both the microbiological safety of fresh-cut avocado treated with ILP as well as to improve its physical and chemical quality. Intense light pulses (ILP) have received considerable attention during the last years after its approval by the U.S. Food and Drug Administration (FDA) in 1996 as a decontamination method for food or food surfaces. This article presents relevant information regarding the effect of ILP treatments combined with quality-stabilizing compounds as a feasible alternative to improve the physical and chemical quality of fresh-cut avocado as well as to guarantee its microbiological safety. © 2011 Institute of Food Technologists®

  6. Survival of Salmonella Newport on Whole and Fresh-Cut Cucumbers Treated with Lytic Bacteriophages.

    Science.gov (United States)

    Sharma, Manan; Dashiell, Gwendolyn; Handy, Eric T; East, Cheryl; Reynnells, Russell; White, Chanelle; Nyarko, Esmond; Micallef, Shirley; Hashem, Fawzy; Millner, Patricia D

    2017-04-01

    Salmonella enterica associated with consumption of cucumbers ( Cucumis sativus ) has led to foodborne outbreaks in the United States. Whole and fresh-cut cucumbers are susceptible to S. enterica contamination during growing, harvesting, and postharvest handling. The application of lytic bacteriophages specific for S. enterica was evaluated to reduce Salmonella populations on cucumbers. Unwaxed cucumbers ('Lisboa' variety, or mini-cucumbers purchased at retail) were inoculated with Salmonella Newport (5 log CFU per cucumber) and were sprayed with 3.2 mL of phosphate-buffered saline (control) or 10 log PFU/ml of SalmoFresh, a Salmonella-specific bacteriophage preparation (phage), to deliver 4.76 × 10(7) PFU/cm(2). Cucumbers were stored at 10 or 22°C for 7 days. Inoculated mini-cucumbers were sliced with a sterile knife to investigate Salmonella transfer to mesocarp, and cut pieces were stored at 4°C for 2 days. Populations (log CFU per cucumber) of Salmonella Newport on phage-treated whole cucumbers were significantly (P cucumbers (4.27 ± 0.37) on day 0. Populations on phage-treated cucumbers stored at 10°C were 1.72 ± 0.77 and 1.56 ± 0.46, which were significantly lower than those on control-treated cucumbers (3.20 ± 0.48 and 2.33 ± 0.25) on days 1 and 4, respectively. Between days 0 and 1, populations on control-treated cucumbers stored at 10 and 22°C declined by 1.07 and 2.47 log CFU per cucumber, respectively. At 22°C, Salmonella Newport populations declined by 2.37 log CFU per cucumber between days 0 and 1. Phage application to whole cucumbers before slicing did not reduce the transfer of Salmonella Newport to fresh-cut slices. Lytic phage application may be a potential intervention to reduce Salmonella populations on whole cucumbers.

  7. A microbiological survey of fresh meat in the supermarket trade. Part 2: beef retail cuts.

    Science.gov (United States)

    Nortjé, G L; Nel, L; Jordaan, E; Naudé, R T; Holzapfel, W H; Grimbeek, R J

    1989-01-01

    An assessment was made of the microbiological quality of the final product (different retail cuts), produced by two different retail supermarket groups (A & B). The influence of sanitary conditions on the microbiological quality of the final product was evaluated, and the possible influences on shelf life were determined. Supermarket group A (Sup group A) received carcasses with significantly lower surface counts of micro-organisms than supermarket group B (Sup group B), while the latter had a more efficient overall sanitation programme than supermarket group A. Five cuts were monitored for the presence of total aerobic counts, psychrotrophic counts, lactobacilli, Enterobacteriaceae and numbers of Pseudomonadaceae present. A shelf life study was also executed by repeating these enumerations on the same meat samples after refrigerated storage at 5°C for 2 and 4 days, respectively. It is generally accepted that a good refrigeration or chilling regime will preserve the inherent meat quality, but in this study it was found that neither served as a guarantee of quality. The more stringent hygiene at retail level of Sup group B yielded consistently lower mean counts of the different bacterial groups for all the meat cuts monitored and, thus meat with an extended shelf life. The total count (at 30°C) on meat cuts was the highest, followed by the psychrotrophs, the Pseudomonadaceae the Enterobacteriaeae and the lactobacilli. Minced meat generally had the highest mean aerobic total microbial counts. This count on minced meat might be a suitable indicator for monitoring the overall sanitary condition of a retail premises. The results re-emphasized the multi-factorial complexity of fresh meat quality and shelf life. The microbial quality of the raw material (carcasses), the maintenance of the cold chain, sanitary condition of premises, equipment and personnel surfaces and general management practices are factors that collectively determine the microbiological quality of the

  8. Examination of bacteriophage as a biocontrol method for salmonella on fresh-cut fruit: a model study.

    Science.gov (United States)

    Leverentz, B; Conway, W S; Alavidze, Z; Janisiewicz, W J; Fuchs, Y; Camp, M J; Chighladze, E; Sulakvelidze, A

    2001-08-01

    The preparation and distribution of fresh-cut produce is a rapidly developing industry that provides the consumer with convenient and nutritious food. However, fresh-cut fruits and vegetables may represent an increased food safety concern because of the absence or damage of peel and rind, which normally help reduce colonization of uncut produce with pathogenic bacteria. In this study, we found that Salmonella Enteritidis populations can (i) survive on fresh-cut melons and apples stored at 5 degrees C, (ii) increase up to 2 log units on fresh-cut fruits stored at 10 degrees C, and (iii) increase up to 5 log units at 20 degrees C during a storage period of 168 h. In addition, we examined the effect of lytic, Salmonella-specific phages on reducing Salmonella numbers in experimentally contaminated fresh-cut melons and apples stored at various temperatures. We found that the phage mixture reduced Salmonella populations by approximately 3.5 logs on honeydew melon slices stored at 5 and 10 degrees C and by approximately 2.5 logs on slices stored at 20 degrees C, which is greater than the maximal amount achieved using chemical sanitizers. However, the phages did not significantly reduce Salmonella populations on the apple slices at any of the three temperatures. The titer of the phage preparation remained relatively stable on melon slices, whereas on apple slices the titer decreased to nondetectable levels in 48 h at all temperatures tested. Inactivation of phages, possibly by the acidic pH of apple slices (pH 4.2 versus pH 5.8 for melon slices), may have contributed to their inability to reduce Salmonella contamination in the apple slices. Higher phage concentrations and/or the use of low-pH-tolerant phage mutants may be required to increase the efficacy of the phage treatment in reducing Salmonella contamination of fresh-cut produce with a low pH.

  9. Physicochemical changes in fresh-cut wax apple (Syzygium samarangenese [Blume] Merrill & L.M. Perry) during storage.

    Science.gov (United States)

    Supapvanich, Suriyan; Pimsaga, Jirapon; Srisujan, Panneewan

    2011-08-01

    Physicochemical changes, such as peel and flesh colours, total anthocyanin content, browning index, firmness, total soluble solid (TSS), titratable acidity (TA), sugar acid ratio (TSS/TA), antioxidant capacity, total phenolic content and ascorbic acid content, in fresh-cut Taaptimjan wax apple fruit stored at 4±2°C and 12±2°C for 7days were investigated. The skin of fresh-cut fruit stored at 4±2°C showed higher a(∗) value, chroma and total anthocyanin content and lower hue angle than those stored at 12±2°C. Lightness (L(∗) value) and whiteness index of the fresh-cut fruit flesh stored at 12±2°C showed significantly lower than those stored at 4±2°C which related to an significant increase in browning index. Firmness, total soluble solid, titratable acidity and sugar acid ratio did not significant changes during storage. Antioxidant capacity and total phenolic content increased throughout storage. Ascorbic acid content of the fresh-cut fruit stored at 4±2°C remained constant throughout storage whilst ascorbic content at 12±2°C decreased and was lower than that at 4±2°C. At 4±2°C antioxidant capacity and ascorbic acid content were higher than that stored at 12±2°C whilst there was no significant difference in total phenolic content. In conclusion, the reduction of whiteness index and the increase in browning index of fresh-cut wax apple flesh were the key factors affecting its quality and storage at 4±2°C could reduce the change in the flesh colour and maintained the peel colour and nutritional values of fresh-cut wax apple fruit during storage. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. Shelf life of fresh-cut spinach as affected by chemical treatment and type of packaging film

    Directory of Open Access Journals (Sweden)

    A.M. Piagentini

    2002-12-01

    Full Text Available Fresh-cut vegetables are an important and rapidly developing class of convenience foods. Their storage life may be greatly reduced due to their high rates of respiration and transpiration and the possibility of enzymatic and microbiological deterioration. Consequently, the objective of this work was to determine the shelf life and the failure attribute that conditioned the shelf life of fresh-cut spinach treated with chemical solutions and packaged in bags with different permeabilities. The shelf life of fresh-cut vegetables was defined as the time of refrigerated storage at which any one of the sensory attributes scored below 7 or when the microbiological counts exceeded 5.10(7 CFU/g. Fresh-cut spinach was treated with citric acid and ascorbic acid solutions and packaged in mono-oriented polypropylene (OPP bags or low-density polyethylene (LDPE bags. Sensory attributes and total microbial counts were evaluated throughout refrigerated storage. Response surface methodology (RSM was used to study the simultaneous effect of chemical treatment and refrigerated storage time on sensory and microbiological quality of fresh-cut spinach. A quadratic polynomial regression model was assumed for predicting off-odor, general appearance, wilting, browning, color, and mesophilic aerobic population. Type of packaging film only influenced development of off-odor (p£0.001 and had no effect on visual sensory attributes or microbiological counts (p>0.05. Development of off-odor was the attribute that limited shelf life of fresh-cut spinach packaged in OPP bags. On the other hand, shelf life of samples packaged in LDPE bags was dependent on a decrease in general appearance or an increase in microbiological counts, depending on the chemical treatment used.

  11. Fresh-cut fruits and vegetables: Critical factors influencing microbiology and novel approaches to prevent microbial risks—A review

    Directory of Open Access Journals (Sweden)

    Ovais Shafiq Qadri

    2015-12-01

    Full Text Available Fruits and vegetables comprise an essential part of human diet as they are the major source of dietary nutrients of great importance. Consumption of fruits has been found to counteract many of the chronic diseases, including cancers and cardiovascular diseases. Therefore, recommendations for a balanced diet must include the consumption of fresh fruits and vegetables. Consumers in developing countries have become more concerned about the nutritional and sensory aspects as well as the safety of the food they eat due to growing health awareness. At the same time, consumer demand for convenience products is increasing and so is the demand for fresh-cut fruits and vegetables. Fresh-cut market has expanded considerably in recent years. However, quality and safety of such products are an issue of concern as these products can act as vehicles for transmitting infectious diseases. Furthermore, fresh-cut produce is more susceptible to spoilage and can facilitate rapid growth of spoilage micro-organisms as well as the micro-organisms of public health significance. Nonetheless, keeping in consideration the vast scope of fresh-cut products, this article intends to thoroughly review information about microbiology and public health risks associated with them. Discussions regarding different approaches to extend the shelf life and to minimize the risk of infection associated with their consumption are also included.

  12. Bacteriological survey of ready-to-eat lettuce, fresh-cut fruit, and sprouts collected from the Swiss market.

    Science.gov (United States)

    Althaus, D; Hofer, E; Corti, S; Julmi, A; Stephan, R

    2012-07-01

    The consumption of ready-to-eat fresh vegetables has increased significantly in the recent decades. So far, no data are available on the bacteriological burden and the prevalence of foodborne pathogens in ready-to-eat lettuce, fresh-cut fruit, and sprouts on the Swiss market. This study was based on investigations carried out during 2 months of the summer season in 2011. Samples of 142 salads, 64 fresh-cut fruit, and 27 sprouts were included in this study. Escherichia coli, an indicator microorganism for fecal contamination, was only found in 5 lettuce samples, with amounts ranging between 2 and 3 log CFU/g. No Salmonella spp. were detected from any of the 233 samples analyzed in this study, and a low occurrence was found for contamination with L. monocytogenes, Shiga toxin-producing E. coli, enteropathogenic E. coli, and Cronobacter. From the results of the present study, we conclude that even in a country where the use of chlorine solutions to sanitize fruits and vegetables in the fresh-cut industry is not allowed, it is possible to produce ready-to-eat lettuce, fresh-cut fruit, and sprouts with high microbiological standards. Strict maintenance of good practices of hygiene at preharvest, harvest, and postharvest levels is of central importance to ensure both public health protection and product quality.

  13. The influence of pulsed light exposure mode on quality and bioactive compounds of fresh-cut mangoes.

    Science.gov (United States)

    de Almeida Lopes, Mônica Maria; Silva, Ebenezer Oliveira; Laurent, Sandrine; Charles, Florence; Urban, Laurent; de Miranda, Maria Raquel Alcântara

    2017-07-01

    This study investigated the effect of pulsed light (PL) on the respiratory rate, quality (firmness, color and soluble solid content), bioactive compounds (ascorbate and carotenoid) and total antioxidant activity of fresh-cut "Tommy Atkins" mangoes. Fresh-cut mangoes were subjected to PL treatments: control (0P), 1 pulse (1P; 0.7 J cm(-2)), 4 successive pulses (4P; 2.80 J cm(-2)) and 1 pulse per day for 4 days (1P4D; 2.80 J cm(-2)) before storage for 7 days at 6 °C. The 1P and the 4P treatments reduced fresh mass loss during storage, while 4P-treated samples also showed a slower decline of yellow color, as shown by parameter b and overall better visual appearance. After 7 days of storage, total ascorbate content was 40% higher in the 1P4D treatment than in control, whereas total carotenoid content (0.894 mg g(-1) FM) and total antioxidant activity (144 μmol trolox 100 g(-1) FM) were the highest in the 4P-treated samples. Results suggest that PL mode of application is more important than the fluence or final dose received by fresh-cut mangoes; moreover, 4P is an effective method to preserve, or even improve quality of fresh-cut mangoes.

  14. Use of chemical sanitizers to reduce microbial populations and maintain quality of whole and fresh-cut cantaloupe.

    Science.gov (United States)

    Fan, Xuetong; Annous, Bassam A; Keskinen, Lindsey A; Mattheis, James P

    2009-12-01

    Whole cantaloupes either not inoculated or inoculated with Salmonella Poona were submerged in water, 180 ppm of chlorine, acidified calcium sulfate (ACS: 1.2% Safe(2)O-ACS50), 1,000 ppm of acidified sodium chlorite (ASC), 80 ppm of peroxyacetic acid (PAA), and a combination of ACS and PAA for 10 min. Although only ASC and the combination of ACS and PAA significantly reduced the aerobic plate count of samples taken from the surface of whole cantaloupe (compared with samples taken from cantaloupe submerged in water only), all treatments reduced yeast and mold counts on the whole cantaloupe. However, none of the treatments of whole cantaloupes consistently reduced yeast and mold counts for the samples of fresh-cut cantaloupes. The aerobic plate counts for fresh-cut cantaloupe were reduced by 1 to 2 log CFU/g by sanitization of whole fruit with ASC, ACS, and the combination of ACS and PAA. The low bacterial population on the fresh-cut fruit was maintained during 14 days of storage at 4 degrees C. All treatments had a limited effect on the population of Salmonella, achieving no more than a 1.5-log reduction of the pathogen inoculated on the surface of the whole cantaloupes. Salmonella was nondetectable via direct plating (with a detection limit of 0.4 log CFU/g) in fresh-cut cantaloupes prepared from whole cantaloupes treated with any of the sanitizers. However, after enrichment, Salmonella often was detectable. Color, texture, soluble solids, pH, ascorbic acid, and drip loss of cut cantaloupes were not consistently affected by any of the whole-fruit treatments. Overall, treatments of whole cantaloupe with ASC, ACS, and the combination of ACS and PAA at the concentrations tested permitted a significant reduction in Salmonella and native microflora of whole and cut fruit; however, Salmonella still could be found in cut cantaloupes from all treatments.

  15. Discrimination methods for biological contaminants in fresh-cut lettuce based on VNIR and NIR hyperspectral imaging

    Science.gov (United States)

    Mo, Changyeun; Kim, Giyoung; Kim, Moon S.; Lim, Jongguk; Lee, Seung Hyun; Lee, Hong-Seok; Cho, Byoung-Kwan

    2017-09-01

    The rapid detection of biological contaminants such as worms in fresh-cut vegetables is necessary to improve the efficiency of visual inspections carried out by workers. Multispectral imaging algorithms were developed using visible-near-infrared (VNIR) and near-infrared (NIR) hyperspectral imaging (HSI) techniques to detect worms in fresh-cut lettuce. The optimal wavebands that can detect worms in fresh-cut lettuce were investigated for each type of HSI using one-way ANOVA. Worm-detection imaging algorithms for VNIR and NIR imaging exhibited prediction accuracies of 97.00% (RI547/945) and 100.0% (RI1064/1176, SI1064-1176, RSI-I(1064-1173)/1064, and RSI-II(1064-1176)/(1064+1176)), respectively. The two HSI techniques revealed that spectral images with a pixel size of 1 × 1 mm or 2 × 2 mm had the best classification accuracy for worms. The results demonstrate that hyperspectral reflectance imaging techniques have the potential to detect worms in fresh-cut lettuce. Future research relating to this work will focus on a real-time sorting system for lettuce that can simultaneously detect various defects such as browning, worms, and slugs.

  16. Pathway Analysis and Metabolites Identification by Metabolomics of Etiolation Substrate from Fresh-Cut Chinese Water Chestnut (Eleocharis tuberosa

    Directory of Open Access Journals (Sweden)

    Yi-Xiao Li

    2016-12-01

    Full Text Available Fresh-cut Chinese water chestnuts (CWC turn yellow after being peeled, reducing their shelf life and commercial value. Metabolomics, the systematic study of the full complement of small molecular metabolites, was useful for clarifying the mechanism of fresh-cut CWC etiolation and developing methods to inhibit yellowing. In this study, metabolic alterations associated with etiolation at different growth stages (0 day, 2 days, 3 days, 4 days, 5 days from fresh-cut CWC were investigated using LC–MS and analyzed by pattern recognition methods (principal component analysis (PCA, partial least squares-discriminant analysis (PLS-DA, and orthogonal projection to latent structures-discriminant analysis (OPLS-DA. The metabolic pathways of the etiolation molecules were elucidated. The main metabolic pathway appears to be the conversion of phenylalanine to p-coumaroyl-CoA, followed by conversion to naringenin chalcone, to naringenin, and naringenin then following different pathways. Firstly, it can transform into apigenin and its derivatives; secondly, it can produce eriodictyol and its derivatives; and thirdly it can produce dihydrokaempferol, quercetin, and myricetin. The eriodictyol can be further transformed to luteolin, cyanidin, dihydroquercetin, dihydrotricetin, and others. This is the first reported use of metabolomics to study the metabolic pathways of the etiolation of fresh-cut CWC.

  17. Pathway Analysis and Metabolites Identification by Metabolomics of Etiolation Substrate from Fresh-Cut Chinese Water Chestnut (Eleocharis tuberosa).

    Science.gov (United States)

    Li, Yi-Xiao; Pan, Yong-Gui; He, Feng-Ping; Yuan, Meng-Qi; Li, Shang-Bin

    2016-12-01

    Fresh-cut Chinese water chestnuts (CWC) turn yellow after being peeled, reducing their shelf life and commercial value. Metabolomics, the systematic study of the full complement of small molecular metabolites, was useful for clarifying the mechanism of fresh-cut CWC etiolation and developing methods to inhibit yellowing. In this study, metabolic alterations associated with etiolation at different growth stages (0 day, 2 days, 3 days, 4 days, 5 days) from fresh-cut CWC were investigated using LC-MS and analyzed by pattern recognition methods (principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and orthogonal projection to latent structures-discriminant analysis (OPLS-DA)). The metabolic pathways of the etiolation molecules were elucidated. The main metabolic pathway appears to be the conversion of phenylalanine to p-coumaroyl-CoA, followed by conversion to naringenin chalcone, to naringenin, and naringenin then following different pathways. Firstly, it can transform into apigenin and its derivatives; secondly, it can produce eriodictyol and its derivatives; and thirdly it can produce dihydrokaempferol, quercetin, and myricetin. The eriodictyol can be further transformed to luteolin, cyanidin, dihydroquercetin, dihydrotricetin, and others. This is the first reported use of metabolomics to study the metabolic pathways of the etiolation of fresh-cut CWC.

  18. Effect of mild heat-shock treatments on pink discoloration and physiological parameters in fresh-cut iceberg lettuce

    NARCIS (Netherlands)

    Paillart, M.J.M.; Otma, Els; Woltering, E.J.

    2016-01-01

    Pink discoloration is one of the major quality issues occurring in fresh-cut lettuce. Low oxygen atmosphere in modified atmosphere packaging prevents pinking but may lead to other major quality losses such as fermentation, growth of lactic acid bacteria and associated production of off-odours. The a

  19. Comparison of Sodium Acid Sulfate and UV-C Treatment on Browning and Storage Quality of Fresh-Cut Potatoes

    Directory of Open Access Journals (Sweden)

    Yajing Xie

    2017-01-01

    Full Text Available Fresh-cut vegetables, such as potato chips, get brown quickly and can easily be infected by bacterium during storage. Sodium acid sulfate (SAS and UV-C treatments are regarded as effective methods for food preservation. In this study, the effects of SAS, UV-C treatment, and their combination on fresh-cut potatoes during storage were evaluated. Compared with the control, all of the treatments were effective in inhibiting the bacterial growth during the whole storage period. Also, both SAS and SAS + UV-C treatments significantly decreased browning and polyphenol oxidase (PPO activity and increased the firmness and malondialdehyde (MDA contents, while the UV-C treatment has no good effects on protecting such storage qualities in fresh-cut potatoes. However, when compared with SAS treatment, the combination of SAS and UV-C treatment did not promote the effect in protecting the storage abilities. Thus, it was concluded that SAS is a better treatment in extending shelf life and controlling the quality of fresh-cut potatoes during storage compared to UV-C treatment.

  20. Effectiveness of 1-Methylcyclopropene (1-MCP Combination with Nisin-EDTA Treatment of Fresh-cut Kiwifruit for Prevention

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2014-02-01

    Full Text Available A comprehensive study was made to determine the effects of 1-MCP (1 &muL L-1 pretreated combined with Nisin-EDTA (0.02 M on fresh-cut kiwifruit slices. Physico-chemical attributes of kiwifruit slices were evaluated every 3 days during storage. The fresh-cut kiwifruits pre-treated with 1-MCP, Nisin-EDTA coating and their combination showed better preservation quality and compared with the control slices during the entire storage period. 1-MCP showed an ability to relieve the pulp softening extent and inhibit total chlorophyll content decrease. Lower Polyphenol Oxidase (PPO and higher ascorbic acid were observed in Nisin-EDTA treated samples which also showed a less total bacteria count compared with the control in the end storage. Moreover, the combination of 1-MCP and Nisin-EDTA was more effective than individual treatment on maintaining the quality of fresh-cut kiwifruit, which suggested that this may be a healthy alternative method for fresh-cut kiwifruit.

  1. Influence of modified atmosphere packaging on volatile compounds and physicochemical and antioxidant attributes of fresh-cut pineapple (Ananas comosus).

    Science.gov (United States)

    Montero-Calderón, Marta; Rojas-Graü, María Alejandra; Aguiló-Aguayo, Ingrid; Soliva-Fortuny, Robert; Martín-Belloso, Olga

    2010-04-28

    The effects of modified atmosphere packaging on volatile compound content and physicochemical and antioxidant attributes of Gold cultivar fresh-cut pineapples were assessed throughout storage at 5 degrees C. Fresh-cut pineapple pieces were packed under LO (low oxygen, 12% O(2), 1% CO(2)), AIR (20.9% O(2)) and HO (high oxygen, 38% O(2)) headspace atmospheres. Methyl butanoate, methyl 2-methylbutanoate, and methyl hexanoate were the most abundant volatiles regardless of the packaging atmosphere and days of storage; whereas most odor active volatiles were methyl and ethyl 2-methylbutanoate, 2,5-dimethyl-4-methoxy-3(2H)-furanone and ethyl hexanoate. Physicochemical attributes of pineapple did not significantly vary, whereas vitamin C content and total antioxidant capacity were lower for fresh-cut pineapple in HO (488 +/- 38 mg/100 mg(fw) and 54.4 +/- 5.7%, respectively) than for LO and AIR packages. Storage life of fresh-cut pineapple was limited to 14 days by volatile compounds losses and fermentation processes.

  2. Processamento mínimo de mamão 'formosa' Fresh cut of 'formosa' papaya

    Directory of Open Access Journals (Sweden)

    Gustavo Henrique de Almeida TEIXEIRA

    2001-01-01

    Full Text Available Este trabalho foi conduzido para verificar o efeito do tamanho do corte, 2,5 x 2,5cm (corte 1 e 2,5 x 5,0cm (corte 2, e da temperatura de armazenamento (3, 6 e 9ºC, na velocidade da modificação da atmosfera ambiente e nas características químicas de mamões do grupo `Formosa' minimamente processados e embalados em copos plásticos (500ml. A concentração de CO2 no interior destes copos aumentou 2 a 3 vezes, durante as primeiras 6 horas após o corte, para depois diminuir e se estabilizar. Esta concentração aumentou com o aumento da temperatura de armazenamento. A umidade dos pedaços diminuiu consideravelmente nos dois primeiros dias, e a temperatura que melhor conservou a umidade foi a de 6ºC. A acidez total titulável foi menor no corte 2, com as maiores reduções a 6 e 9oC. Os teores de sólidos solúveis totais não variaram entre os tratamentos, e os cuidados higiênicos adotados durante o processamento permitiram a obtenção de produtos com baixa contagem microbiana, 10³UFC.g-1 nos pedaços armazenados a 9ºC após sete dias, e com boa manutenção da qualidade sensorial das mesmas. Estes resultados permitem indicar o mamão `Formosa' para a produção de produtos minimamente processados, na forma de pedaços, com conservação refrigerada (3 e 6ºC por um período de 7 dias.This work was undertaken to verify the effect of cutting size, 2.5 x 2.5cm (chunk 1, 2.5 x 5.0cm (chunk 2, and storage temperatures (3, 6 and 9ºC, on atmosphere modification rate and chemical characteristics of `Formosa' fresh-cut papaya packed in plastic cups (500 ml. The CO2 concentration into theses cups increased fron two to three fold during first 6 hours after cutting, then it decreased and stabilized. This concentration increased with the storage temperature increasing. The chunks's moisture remarkably decreased in the first 2 days, and the temperature which best sustained the moisture was 6ºC. The titratable total acidity was lower in chunk 2

  3. Public Health Relevance of Cross-Contamination in the Fresh-Cut Vegetable Industry.

    Science.gov (United States)

    Chardon, Jurgen; Swart, Arno; Evers, Eric; Franz, Eelco

    2016-01-01

    Although quantitative studies have revealed that cross-contamination during the washing stage of fresh produce occurs, the importance of cross-contamination in terms of public health relevance has rarely been assessed. The direct distribution of initially contaminated leafy vegetables to a multitude of servings by cutting and mixing also has not been addressed. The goal of this study was to assess the attribution of both contamination pathways to disease risk. We constructed a transparent and exploratory mathematical model that simulates the dispersion of contamination from a load of leafy greens during industrial washing. The risk of disease was subsequently calculated using a Beta-Poisson dose-response relation. The results indicate that up to contamination loads of 10(6) CFU the direct contamination route is more important than the indirect route (i.e., cross-contamination) in terms of number of illnesses. We highlight that the relevance of cross-contamination decreases with more diffuse and uniform contamination, and we infer that prevention of contamination in the field is the most important risk management strategy and that disinfection of washing water can be an additional intervention to tackle potentially high (>10(6) CFU) point contamination levels.

  4. Estimate of respiration rate and physicochemical changes of fresh-cut apples stored under different temperatures

    Directory of Open Access Journals (Sweden)

    Cristiane Fagundes

    2013-03-01

    Full Text Available In this study, the influence of storage temperature and passive modified packaging (PMP on the respiration rate and physicochemical properties of fresh-cut Gala apples (Malus domestica B. was investigated. The samples were packed in flexible multilayer bags and stored at 2 °C, 5 °C, and 7 °C for eleven days. Respiration rate as a function of CO2 and O2 concentrations was determined using gas chromatography. The inhibition parameters were estimated using a mathematical model based on Michaelis-Menten equation. The following physicochemical properties were evaluated: total soluble solids, pH, titratable acidity, and reducing sugars. At 2 °C, the maximum respiration rate was observed after 150 hours. At 5 °C and 7 °C the maximum respiration rates were observed after 100 and 50 hours of storage, respectively. The inhibition model results obtained showed a clear effect of CO2 on O2 consumption. The soluble solids decreased, although not significantly, during storage at the three temperatures studied. Reducing sugars and titratable acidity decreased during storage and the pH increased. These results indicate that the respiration rate influenced the physicochemical properties.

  5. Effects of hydrogen peroxide treatment on thiol contents in fresh-cut asparagus (Asparagus officinalis) spears.

    Science.gov (United States)

    Demrkol, Omca

    2009-01-01

    In this work, the impact of hydrogen peroxide (H2O2) was investigated on the thiol content of asparagus. Fresh-cut asparagus was treated with H2O2 at varied oxidant concentrations and contact times. A significant decrease (alpha=0.05) was observed in N-acetylcysteine levels treated with 2.5% H2O2 for 10 min and with 5% H2O2 for 3, 5 and 10 min. Captopril and cysteine levels significantly decreased (alpha=0.05) in all and most treatment conditions, respectively. Glutathione levels only significantly decreased with 2.5% and 5% H2O2 for 10 min treatment. In order to determine whether asparagus undergoes oxidative stress, a well-known oxidative stress indicator-the glutathione/oxidized glutathione ratio-was calculated. This study showed that the common use of H2O2 as a disinfectant/sterilizer by the food industry could markedly diminish the important biothiols and develop oxidative stress in asparagus, and potentially in other vegetables as well.

  6. Colour Changes Evaluation of Freshly Cut Alder Veneers Under the Influence of Indoor Sunlight

    Directory of Open Access Journals (Sweden)

    Emilia Adela SALCA

    2011-03-01

    Full Text Available The paper presents an experimental study concerning the colour changes occurred on the surfaces ofblack alder veneers (Alnus glutinosa, obtained from a freshly cut (not treated log, after their exposure tosunlight and darkness, for 1 and 3 months, under indoor conditions.A Chroma Meter Konika Minolta CR-410 device was used for colour measurement.The colorimetric coordinates were recorded before and after the exposure, according to ISO 7724-2.The results highlight a significant decrease of colour lightness, right after the first month of sunlight exposure.The a* and b* colour coordinates showed an increasing tendency with increasing exposure time, whichsignifies a colour darkening under sunlight radiation that penetrates the window glass. Colour differenceswere noticed right after the first month of sunlight exposure, while under darkness conditions, a relativecolour constancy was noticed, the colour changes being less pronounced, but yet perceptible by the humaneye.The study results complete the colorimetric database of veneers used in furniture industry, but theyalso contribute to the rehabilitation of black alder as a wood species with a real potential of use in furnitureindustry.

  7. High hydrostatic pressure as a method to preserve fresh-cut Hachiya persimmons: A structural approach.

    Science.gov (United States)

    Vázquez-Gutiérrez, José Luis; Quiles, Amparo; Vonasek, Erica; Jernstedt, Judith A; Hernando, Isabel; Nitin, Nitin; Barrett, Diane M

    2016-12-01

    The "Hachiya" persimmon is the most common astringent cultivar grown in California and it is rich in tannins and carotenoids. Changes in the microstructure and some physicochemical properties during high hydrostatic pressure processing (200-400 MPa, 3 min, 25 ℃) and subsequent refrigerated storage were analyzed in this study in order to evaluate the suitability of this non-thermal technology for preservation of fresh-cut Hachiya persimmons. The effects of high-hydrostatic pressure treatment on the integrity and location of carotenoids and tannins during storage were also analyzed. Significant changes, in particular diffusion of soluble compounds which were released as a result of cell wall and membrane damage, were followed using confocal microscopy. The high-hydrostatic pressure process also induced changes in physicochemical properties, e.g. electrolyte leakage, texture, total soluble solids, pH and color, which were a function of the amount of applied hydrostatic pressure and may affect the consumer acceptance of the product. Nevertheless, the results indicate that the application of 200 MPa could be a suitable preservation treatment for Hachiya persimmon. This treatment seems to improve carotenoid extractability and tannin polymerization, which could improve functionality and remove astringency of the fruit, respectively. © The Author(s) 2016.

  8. Effectiveness of a bacteriophage in reducing Listeria monocytogenes on fresh-cut fruits and fruit juices.

    Science.gov (United States)

    Oliveira, M; Viñas, I; Colàs, P; Anguera, M; Usall, J; Abadias, M

    2014-04-01

    Listeria monocytogenes is a serious foodborne pathogen and new strategies to control it in food are needed. Among them, bacteriophages hold attributes that appear to be attractive. The objective of this study was to investigate the efficacy of the bacteriophage Listex P100 to control L. monocytogenes growth on melon, pear and apple products (juices and slices) stored at 10 °C. L. monocytogenes grew well in untreated fruit slices. In juices, the pathogen grew in untreated melon, survived in untreated pear and decreased in untreated apple. Phage treatment was more effective on melon followed by pear, but no effect on apple products was observed. Reductions of about 1.50 and 1.00 log cfu plug(-1) for melon and pear slices were found, respectively. In juices, higher reductions were obtained in melon (8.00 log cfu mL(-1)) followed by pear (2.10 log cfu mL(-1)) after 8 days of storage. L. monocytogenes in apple juice was unaffected by phage treatment in which the phage decreased to almost undetectable numbers. These results highlight that Listex P100 could avoid pathogen growth on fresh-cut and in fruit juices with high pH during storage at 10 °C. The combination with other technologies may be required to improve the phage application on high acidity fruits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Apple Puree-Alginate Edible Coating as Carrier of Antimicrobial Agents to Prolong Shelf-Life of Fresh-Cut Apples

    Science.gov (United States)

    Edible coatings with antimicrobial agents can extend the shelf-life of fresh-cut fruit. The effect of lemongrass, oregano oil and vanillin incorporated in apple puree-alginate edible coatings, on the shelf-life of fresh-cut Fuji apples, was investigated. Coated apples were packed in air-filled pol...

  10. Survival and growth parameters of Escherichia Coli 0157:H7, Salmonella Spp. and Listeria Monocytogenes on fresh-cut pieces prepared from whole cantaloupe treated with Lovit sanitizer

    Science.gov (United States)

    Incidence of foodborne illness due to consumption of fresh-cut melons contaminated with human bacterial pathogens and recalls of such contaminated fresh-cut melons continues to be a food safety problem. Cantaloupe rind surfaces were inoculated with a three cocktail of E. coli O157:H7, Salmonella spp...

  11. Evaluation of Combined Disinfection Methods for Reducing Escherichia coli O157:H7 Population on Fresh-Cut Vegetables

    Directory of Open Access Journals (Sweden)

    Eva Petri

    2015-07-01

    Full Text Available Most current disinfection strategies for fresh-cut industry are focused on the use of different chemical agents; however, very little has been reported on the effectiveness of the hurdle technology. The effect of combined decontamination methods based on the use of different sanitizers (peroxyacetic acid and chlorine dioxide and the application of pressure (vacuum/positive pressure on the inactivation of the foodborne pathogen E. coli O157:H7 on fresh-cut lettuce (Lactuca sativa and carrots (Daucus carota was studied. Fresh produce, inoculated with E. coli O157:H7, was immersed (4 °C, 2 min in tap water (W, chlorine water (CW, chlorine dioxide (ClO2: 2 mg/L and peroxyacetic acid (PAA: 100 mg/L in combination with: (a vacuum (V: 10 mbar or (b positive pressure application (P: 3 bar. The product quality and antimicrobial effects of the treatment on bacterial counts were determined both in process washing water and on fresh-cut produce. Evidence obtained in this study, suggests that the use of combined methods (P/V + sanitizers results in a reduction on the microorganism population on produce similar to that found at atmospheric pressure. Moreover, the application of physical methods led to a significant detrimental effect on the visual quality of lettuce regardless of the solution used. Concerning the process water, PAA proved to be an effective alternative to chlorine for the avoidance of cross-contamination.

  12. Behavior of Salmonella spp. and natural microbiota on fresh-cut dragon fruits at different storage temperatures.

    Science.gov (United States)

    Sim, Hui Li; Hong, Yoon-Ki; Yoon, Won Byong; Yuk, Hyun-Gyun

    2013-01-01

    The aim of this study was to determine survival or growth of unadapted, acid-adapted and cold-stressed Salmonella spp., and natural microbiota on fresh-cut dragon fruits at different storage temperatures. Dragon fruits were sliced and spot inoculated with five-strain cocktail of Salmonella spp. at two inoculum levels (2.5 or 5.5 log CFU/g). Inoculated fruits were stored at 28°C for 48h and at 4°C and 12°C for 96 h. Salmonella population significantly increased by 2.4 to 3.0 log CFU/g at low inoculum level, whereas the numbers increased by 0.4 to 0.7 log CFU/g at the high inoculum level on fruits held at 28°C for 48h. Only unadapted and acid-adapted cells grew with 0.7 to 0.9log increase at the low inoculum level at 12°C for 96h. No significant growth was observed at both inoculum levels during storage at 4°C. Overall, acid, starved and cold adaptation of Salmonella spp. did not show significant difference in survival or growth on fresh-cut dragon fruits during storage compared to unadapted control cells. For natural microbiota on the fruit, mesophilic bacterial counts reached to 5-log CFU/g at 28 and 12°C by 9.9 and 52.9h. Similar with Salmonella spp. there was no growth of natural microbiota at 4°C. These results showed that Salmonella spp. could grow on fresh-cut dragon fruits under inappropriate storage conditions, indicating that fresh-cut dragon fruits could be a potential vehicle for salmonellosis. Thus, this study suggests that fresh-cut dragon fruits should be stored at 4°C to ensure the safety as well as to extend the shelf life of fresh-cut dragon fruits. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Evaluating nitrogen utilization efficiency of nonpregnant dry cows offered solely fresh cut grass at maintenance levels.

    Science.gov (United States)

    Stergiadis, S; Chen, X J; Allen, M; Wills, D; Yan, T

    2015-02-01

    The present study aimed to identify key parameters influencing N utilization and develop prediction equations for manure N output (MN), feces N output (FN), and urine N output (UN). Data were obtained under a series of digestibility trials with nonpregnant dry cows fed fresh grass at maintenance level. Grass was cut from 8 different ryegrass swards measured from early to late maturity in 2007 and 2008 (2 primary growth, 3 first regrowth, and 3 second regrowth) and from 2 primary growth early maturity swards in 2009. Each grass was offered to a group of 4 cows and 2 groups were used in each of the 8 swards in 2007 and 2008 for daily measurements over 6 wk; the first group (first 3 wk) and the second group (last 3 wk) assessed early and late maturity grass, respectively. Average values of continuous 3-d data of N intake (NI) and output for individual cows ( = 464) and grass nutrient contents ( = 116) were used in the statistical analysis. Grass N content was positively related to GE and ME contents but negatively related to grass water-soluble carbohydrates (WSC), NDF, and ADF contents ( grass WSC contents and ratios of N:WSC, N:digestible OM in total DM (DOMD), and N:ME ( grass N contents and lower grass WSC, NDF, ADF, DOMD, and ME concentrations were significantly associated with greater MN, FN, and UN ( grass lower in N and greater in fermentable energy in animals fed solely fresh grass at maintenance level can improve N utilization, reduce N outputs, and shift part of N excretion toward feces rather than urine. These outcomes are highly desirable in mitigation strategies to reduce nitrous oxide emissions from livestock. Equations predicting N output from BW and grass N content explained a similar amount of variability as using NI and grass chemical composition (excluding DOMD and ME), implying that parameters easily measurable in practice could be used for estimating N outputs. In a research environment, where grass DOMD and ME are likely to be available, their

  14. The effectiveness of ozone and acidulant treatments in extending the refrigerated shelf life of fresh-cut potatoes.

    Science.gov (United States)

    Calder, Beth L; Skonberg, Denise I; Davis-Dentici, Katherine; Hughes, Brianna H; Bolton, Jason C

    2011-10-01

    The objective of the study was to determine the effectiveness of acidulant dip treatments (with or without aqueous ozone) to reduce enzymatic browning and to extend the shelf life of fresh-cut potato slices during refrigerated storage (4 °C) for 28 d. Potato slices subjected to aqueous ozone (2 ppm) had significantly (P≤ 0.05) higher L-values and lower a-values, but ozone did not appear to have any effect on aerobic plate counts (APCs) or polyphenol oxidase (PPO) activity. NatureSeal (NS) and sodium acid sulfate (SAS) were the most effective acidulant treatments in reducing browning (significantly [P≤ 0.05] higher L-values, lower a-values, and browning index values) regardless of ozone treatment. NS and SAS also had lower PPO activity compared to other treatments on days 0 and 28, and significantly (P≤ 0.05) lower APCs (≤2.00 log CFU/g) over refrigerated storage. Therefore, the SAS treatment was comparable to NS, a commercially available product, and showed promise as an effective antibrowning dip to reduce browning and spoilage in fresh-cut potato products. Practical Application:  A 1% SAS dip treatment which included 1% citric and 1% ascorbic acid was found to be an effective antibrowning dip for fresh-cut potatoes along with NatureSeal®'s PS-10, compared to other treatments. They were both effective in maintaining low microbial counts over refrigerated storage. Additionally, aqueous ozone washes (2 ppm) showed significant benefits to reduce browning; however, ozone did not affect microbial counts or PPO enzyme activity. Therefore, the SAS treatment could have potential use in the fruit and vegetable industry to reduce browning and spoilage in fresh-cut potato products.

  15. Modelling sensorial and nutritional changes to better define quality and shelf life of fresh-cut melons

    Directory of Open Access Journals (Sweden)

    Maria Luisa Amodio

    2013-06-01

    Full Text Available The shelf life of fresh-cut produce is mostly determined by evaluating the external appearance since this is the major factor affecting consumer choice at the moment of purchase. The aim of this study was to investigate the degradation kinetics of the major quality attributes in order to better define the shelf life of fresh-cut melons. Melon pieces were stored for eight days in air at 5°C. Sensorial and physical attributes including colour, external appearance, aroma, translucency, firmness, and chemical constituents, such as soluble solids, fructose, vitamin C, and phenolic content, along with antioxidant activity were monitored. Attributes showing significant changes over time were used to test conventional kinetic models of zero and first order, and Weibullian models. The Weibullian model was the most accurate to describe changes in appearance score, translucency, aroma, firmness and vitamin C (with a regression coefficient always higher than 0.956, while the other parameters could not be predicted with such accuracy by any of the tested models. Vitamin C showed the lowest kinetic rate among the model parameters, even though at the limit of marketability (appearance score 3, estimated at five days, a loss of 37% of its initial content was observed compared to the fresh-cut product, indicating a much lower nutritional value. After five days, the aroma score was already 2.2, suggesting that this quality attribute, together with the vitamin C content, should be taken into account when assessing shelf life of fresh-cut melons. In addition, logistical models were used to fit the percentage of rejected samples on the basis of non-marketability and non-edibility (appearance score <3 and <2, respectively. For both parameters, correlations higher than 0.999 were found at P<0.0001; for each mean score this model helps to understand the distribution of the samples among marketable, nonmarketable, and non-edible products.

  16. Recent advances in modified atmosphere packaging and edible coatings to maintain quality of fresh-cut fruits and vegetables.

    Science.gov (United States)

    Ghidelli, Christian; Pérez-Gago, María B

    2016-07-28

    Processing of fruits and vegetables generates physiological stresses in the still living cut tissue, leading to quality deterioration and shorter shelf-life as compared with fresh intact produces. Several strategies can be implemented with the aim to reduce the rate of deterioration of fresh-cut commodities. Such strategies include low temperature maintenance from harvest to retail and the application of physical and chemical treatments such as modified atmosphere packaging (MAP) with low O2 and high CO2 levels and antioxidant dips. Other technologies such as edible coatings with natural additives, new generation of coatings using nanotechnological solutions such as nanoparticles, nanoencapsulation, and multilayered systems, and non-conventional atmospheres such as the use of pressurized inert/noble gases and high levels of O2 have gained a lot of interest as a possibility to extend the shelf life of minimally processed fruits and vegetables. However, the high perishability of these products challenges in many cases their marketability by not achieving sufficient shelf life to survive the distribution system, requiring the combination of treatments to assure safety and quality. This review reports the recent advances in the use of MAP, edible coatings, and the combined effect of both technologies to extend the shelf life of fresh-cut fruits and vegetables.

  17. Effect of supercritical carbon dioxide pasteurization on natural microbiota, texture, and microstructure of fresh-cut coconut.

    Science.gov (United States)

    Ferrentino, Giovanna; Balzan, Sara; Dorigato, Andrea; Pegoretti, Alessandro; Spilimbergo, Sara

    2012-05-01

    The objective of the present study was the evaluation of the effectiveness of supercritical carbon dioxide (SC-CO(2)) as a nonthermal technology for the pasteurization of fresh-cut coconut, as an example of ready-to-eat and minimally processed food. First, the inactivation kinetics of microbiota on coconut were determined using SC-CO(2) treatments (pressures at 8 and 12 MPa, temperatures from 24 to 45 °C, treatment times from 5 to 60 min). Second, the effects of SC-CO(2) on the hardness and microstructure of fresh-cut coconut processed at the optimal conditions for microbial reduction were investigated. SC-CO(2) treatment of 15 min at 45 °C and 12 MPa induced 4 log CFU/g reductions of mesophilic microorganisms, lactic acid bacteria, total coliforms, and yeasts and molds. The hardness of coconut was not affected by the treatment but the samples developed an irregular and disorderly microstructure. Results suggested the potential of SC-CO(2) in preserving fresh-cut fruits and ready-to-eat products. © 2012 Institute of Food Technologists®

  18. Cassava starch coating and citric acid to preserve quality parameters of fresh-cut "Tommy Atkins" mango.

    Science.gov (United States)

    Chiumarelli, Marcela; Pereira, Leila M; Ferrari, Cristhiane C; Sarantópoulos, Claire I G L; Hubinger, Miriam D

    2010-06-01

    Combination of citric acid dipping (5 g/L) and cassava starch coating (10 g/L), with and without glycerol (10 g/L), was studied to verify the effectiveness of these treatments to inhibit enzymatic browning, to reduce respiration rate, and to preserve quality parameters of "Tommy Atkins" fresh-cut mangoes during storage at 5 degrees C. Color characteristics (L and C), mechanical properties (stress at failure), weight loss, beta-carotene content, sensory acceptance, and microbial growth of fruits were evaluated during 15 d. The respiration rate of fruit subjected to the treatments was also analyzed. Nontreated fresh-cut mango was used as a control sample. Cassava starch edible coatings and citric acid dipping promoted a decrease in respiration rate of mango slices, with values up to 41% lower than the control fruit. This treatment also promoted better preservation of texture and color characteristics of mangoes and delayed carotenoid formation and browning reactions during storage. Moreover, the treated fruit showed great sensory acceptance by consumers throughout the whole storage period. However, the use of glycerol in the coating formulation was not efficient in the maintenance of quality parameters of fresh-cut mangoes, promoting a higher weight loss of samples, impairing fruit texture characteristics, increasing carotenogenesis, and favoring microbial growth during storage.

  19. Effects of Organic Acids Treatments with or without Ultra-Sonic Treatment on Increasing the Shelf Life of Fresh Cut Kiwifruit

    Directory of Open Access Journals (Sweden)

    A. Mansoory

    2016-02-01

    Full Text Available The market sales of ready to use fresh cut fruits have grown rapidly in recent decades. Kiwi fruit is an important fruit that its marketing as fresh cut has increased in recent years. The main limiting factors in shelf life of fresh cut fruits are microbial spoilage, drastic softening and browning. In this study, the effects of oxalic and citric acids, both at 0, 2, 4 and 6 mM concentrations, with or without ultra-sonic treatment were investigated on the increasing the shelf life of fresh cut kiwi fruit. After treatments, the fresh slices were stored at 2°C for 7 or 14 days and assessed for several traits and analyzed. Results showed that, oxalic and citric acid treated slices, in comparison to the control, had greater marketability, as well as higher flesh firmness, titrable acidity, ascorbic acid content, total phenol content and antioxidant capacity and smaller bacterial forming colony unit (CFU. Among the treatments, 2, 4 and 6 mM oxalic acid and 6 mM citric acid treatments were found more appropriate than the reaming treatments. Application of ultra-sonic treatment, despite the reduction of microbial load and maintaining antioxidant capacity, had no effects on marketability of fresh cut kiwi fruit. Hence, application of organic acid treatments as dipping can be used to increase the shelf life of fresh cut kiwi fruit.

  20. Determinação da microflora em rabanetes minimamente processados Determination of microorganisms in fresh-cut radishes

    Directory of Open Access Journals (Sweden)

    Juan S del Aguila

    2006-03-01

    Full Text Available O presente trabalho visou comparar dois tratamentos de sanitização e identificar alguns microorganismos associados ao processamento mínimo da raiz de rabanete. Foram avaliados dois métodos de sanitização: 1 sanitização convencional: raízes de rabanete minimamente processadas em retalhos receberam uma única sanitização, por 3 minutos em uma solução de 200 mg L-1 de cloro ativo; 2 sanitização adicional: raízes de rabanete minimamente processadas foram inicialmente sanitizadas na "área suja", numa solução de 200 mg L-1 de cloro ativo por 10 minutos, para posteriormente ingressar na "área limpa", e receber uma segunda sanitização nas mesmas condições do tratamento 1. As análises microbiológicas foram realizadas em duas fases: a após o corte; e b no 10º dia de armazenamento a 5ºC (±1ºC e 90% (±5% UR. Para cada dia de análise foram utilizadas 4 repetições de 130 g de raiz de rabanete minimamente processada. As contagens de bactérias psicrotróficas no tratamento 2 mantiveram-se dentro dos limites aceitáveis. No tratamento 1 obteve-se, no 10º dia de armazenamento, 5,8 x 10(6 UFC g-1, equivalente ao limite máximo recomendado. Não foi detectada presença de coliformes e Salmonella em ambos os tratamentos. Conclui-se que uma primeira sanitização, com 200 mg L-1 de cloro ativo por 10 minutos, é recomendável para a obtenção de raízes de rabanete minimamente processadas de qualidade até o 10º dia de armazenamento a 5ºC, permitindo a comercialização do produto dentro do estabelecido pela legislação vigente de alimentos frescos.The present work was carried out to compare two sanitation treatments and to identify some microorganisms associated with fresh cut radishes. Two sanitation methods were evaluated: 1 conventional sanitation: fresh cut radishes received a single sanitation, for 3 minutes in a solution of 200 mg L-1 of active chlorine; 2 additional sanitation: fresh cut radishes were sanitated

  1. 包装材料对鲜切菠萝保鲜效果的影响%Fresh-keeping effects of packaging materials on fresh-cut pineapple

    Institute of Scientific and Technical Information of China (English)

    覃海元; 潘嫣丽; 黄雪明; 黎朝惠

    2011-01-01

    The fresh-keeping effect of different kinds of packaging materials on fresh-cut pineapple was studied. Pineapple were chosen,peeled and cut to wedges(1. 5~2. 0cm chick). Dipped in 0. 5% citric acid solution for 3min,the pineapple wedges were packaged in plastic trays and covered with polyethylene(PE)film,high-density polyethylene(HDPE)bags and polyethylene-polypropylene(PE/PP)composite bags respectively,or packaged in polyester(PET)cup and covered with a PET top having a 3mm diameter hole,and then stored at 5℃ for 10 days. The fresh-cut pineapples were measured at 0,2,4,6,8,10 day respectively. The results showed that PE/PP and PET packaging materials with low gas-permeability could reduce weight loss,browning,juice leakage,electrolyte leakage and dehydroascorbic acid loss more than PE and HDPE films did,but all the packaging materials did almost the same effects on the acid and TSS contents.%研究不同包装材料对鲜切菠萝的保鲜效果。菠萝经挑选、去皮后切成1.5~2.0cm厚的切片,用0.5%柠檬酸溶液浸泡护色3min后,放入塑料托盘中,分别用PE保鲜膜、HDPE保鲜袋和PE/PP复合袋包裹,或放入PET保鲜盒中并用带有1个直径3mm的盖封口,放入5℃的冰柜里冷藏10d;当天和每2d检测1次样品。结果表明,透气性差的PE/PP袋和PET盒较PE膜和HDPE袋更有利于减少鲜切菠萝的失重、褐变、渗汁、相对电导率增加和还原型抗坏血酸损失,但不同包装材料对总酸和可溶性固形物含量的影响不大。

  2. Color, flavor, texture, and nutritional quality of fresh-cut fruits and vegetables: desirable levels, instrumental and sensory measurement, and the effects of processing.

    Science.gov (United States)

    Barrett, Diane M; Beaulieu, John C; Shewfelt, Rob

    2010-05-01

    The color, flavor, texture, and the nutritional value of fresh-cut fruit and vegetable products are factors critical to consumer acceptance and the success of these products. In this chapter, desirable and undesirable quality attributes of fresh-cut fruit and vegetable products are reviewed. Both instrumental and sensory measurements for determining these critical quality attributes are discussed. The advantages and disadvantages of sensory and instrumental quality measurements are described. A review of typical unit operations involved in the production of fresh-cut products is presented. The effects of fresh-cut processing techniques and treatments on sensory quality, including the appearance, texture, flavor (taste and aroma) of vegetables, and fruits are detailed.

  3. Utilization of physicochemical variables developed from changes in sensory attributes and consumer acceptability to predict the shelf life of fresh-cut mango fruit

    National Research Council Canada - National Science Library

    Salinas-Hernández, Rosa María; González-Aguilar, Gustavo A; Tiznado-Hernández, Martín Ernesto

    2015-01-01

    ...*, chroma and hue angle), total soluble solids (TSS), firmness (F), pH, acidity, and the sensory attributes of appearance, brightness, browning, odor, flavor, texture, color, acidity and sweetness were evaluated in fresh cut mangoes (FCM...

  4. Physicochemical, sensory, and nutritional quality of fresh-cut "Rojo Brillante" persimmon affected by maturity stage and antibrowning agents.

    Science.gov (United States)

    Sanchís, Elena; Mateos, Milagros; Pérez-Gago, María B

    2016-10-01

    To prevent enzymatic browning of fresh-cut 'Rojo Brillante' persimmon, different combinations of ascorbic acid (AA) and citric acid (CA) with calcium chloride (CaCl2) were tested in fruit harvested at two maturity stages (MS1 and MS2). Color, firmness, sensory quality, total vitamin C, radical scavenging activity, total phenolic content, and carotenoids were evaluated over nine days of storage at 5 ℃. Antibrowning dips reduced enzymatic browning if compared with the control samples. Selecting fruits with good firmness and the addition of 10 g/l CaCl2 help prevent loss of firmness of fresh-cut "Rojo Brillante" persimmons treated with acidic solutions as antibrowning agents to control enzymatic browning. The limit of marketability of the persimmon fruit processed at MS1 was significantly reduced by the burst of the disorder known as "flesh browning," and only the samples treated with 10 g/l CA + 10 g/l CaCl2 maintained a limit of marketability close to seven days. At MS2, all the antibrowning solutions allowed a limit of marketability of seven storage days at 5 ℃. Nutritional quality was not affected by either antibrowning dips or cutting processes, but MS at harvest was. © The Author(s) 2016.

  5. Efficacy of gaseous chlorine dioxide on inactivation of Escherichia coli O157:H7 on surfaces of artificially inoculated fresh-cut Romaine lettuce leaves

    Science.gov (United States)

    Efficacy of antimicrobial agents in inactivating pathogenic microorganisms on fresh and fresh-cut produce surfaces in limited by the accessibility of such agents to the produce surfaces where the microorganisms are residing. Other factors contribute to this problem include biofilm formation by the m...

  6. FRUIT JUICES AS AN ALTERNATIVE TECHNIQUE FOR CONSERVATION OF FRESH-CUT BANANA

    OpenAIRE

    ANDERSON ADRIANO MARTINS MELO; LEONARDO THOMAZ DINIZ; ADRIANO DO NASCIMENTO SIMÕES; ROLF PUSCHMANN

    2014-01-01

    Browning discoloration after cutting is detrimental for the quality of a number of fruits and vegetables, such as banana, apple, pear, potato, and some roots such as cassava, yam, and others. Browning and softening compromise banana after cut shelf-life in a few hours under cold storage. Therefore, anti-browning compounds have been applied to slices before packing. Some commonly used substances are calcium chloride, ascorbic acid, cysteine and citric acid, in immersed inchemical mixtures. Rec...

  7. Effect of Calcium Lactate and Heat-Shock on Texture in Fresh-Cut Lettuce During Storage

    OpenAIRE

    Martin-Diana, Ana Belen; Rico, Daniel; Frias, Jesus Maria; Henehan, Gary; Mulcahy, Jemina; Barat, J.; Barry-Ryan, Catherine

    2006-01-01

    Textural and microstructural changes in fresh-cut lettuce were analysed over 12 days storage. The vegetable was treated with 120 ppm chlorine and with 15 g/L calcium lactate at room temperature (18–20 °C) and at 50 °C (heat-shock). Texturometer analysis showed that samples washed with calcium lactate had significantly (p > 0.05) higher crispness values than samples washed with chlorine. However the use of 50 °C treatment (heat-shock) gave better textural properties at the end of storage and s...

  8. Effect of Ozone and Calcium Lactate Treaments on Browning and Textured Properties of Fresh-Cut Lettuce

    OpenAIRE

    Rico, Daniel; Martin-Diana, Ana Belen; Henehan, Gary; Frias, Jesus Maria; Barry-Ryan, Catherine

    2006-01-01

    The effects of three treatments, 1 mg L−1 ozone at 18–20 °C, 15 g L−1 calcium lactate (CLac) at 50 °C and a combination thereof, were compared on fresh-cut lettuce over 10 days of refrigerated storage. Respiration rate, browning and texture were examined as main quality indicators. The use of ozone produced a significantly (P < 0.05) higher oxygen decline than the use of CLac (from day 3 to day 10). At the end of storage, CLac (alone or combined with ozone) samples had higher oxygen content (...

  9. Nutritional and sensory quality during refrigerated storage of fresh-cut mints (Mentha×piperita and M. spicata).

    Science.gov (United States)

    Curutchet, Ana; Dellacassa, Eduardo; Ringuelet, Jorge A; Chaves, Alicia R; Viña, Sonia Z

    2014-01-15

    The effect of storage time on quality attributes of refrigerated fresh-cut mints (Mentha×piperita and M. spicata) was studied. Atmosphere composition, respiratory activity, weight loss, surface colour, total chlorophyll, carotenoids, browning potential, total phenols, flavonoids, radical-scavenging activity, ascorbic acid and essential oil yield and composition were analysed. Respiratory activity of peppermint and spearmint samples diminished moderately (42% and 28%, respectively) after 21days at 0°C. A slight modification of the internal atmosphere was achieved. Surface colour, chlorophyll, carotenoid and antioxidant compounds remained almost constant. The yield of essential oil did not change or it showed an apparent increase after 21days at 0°C, depending on plant growth stage. The characteristic flavour components of peppermint (menthone and menthol) increased, while the contents of the main constituents of spearmint essential oil showed minor variations after storage. The conditions assayed for packaging and storing fresh-cut mints were adequate to achieve a relatively long shelf life and they retained their antioxidant properties. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. A New On-Line Detecting Apparatus of the Residual Chlorine in Disinfectant for Fresh-Cut Vegetables

    Science.gov (United States)

    Hu, Chao; Su, Shu-Qiang; Li, Bao-Guo; Liu, Meng-Fang

    With the fast development of modern food and beverage industry, fresh-cut vegetables have wider application than before. During the process of sterilization in fresh-cut vegetables, the concentration of chloric disinfectant is usually so high that the common sensor can't be used directly on the product line. In order to solve this problem, we have invented a new detecting apparatus which could detect high concentration of chloric disinfectant directly. In this paper, the working principle, main monitor indicators, application and technical creations of the on-line apparatus have been discussed, and we also carried on the experimental analysis for its performance. The actual demands in factory could be met when the detecting flux is 2L/min, the dilution ratio is 15 and input amount of the disinfectant is 200ml per time, the max of the detecting deviation achieves ±4.8ppm(mg/L). The main detecting range of residual chlorine is 0~300ppm.

  11. Disinfection potential of ozone, ultraviolet-C and their combination in wash water for the fresh-cut vegetable industry.

    Science.gov (United States)

    Selma, María V; Allende, Ana; López-Gálvez, Francisco; Conesa, María A; Gil, María I

    2008-09-01

    The purpose of this research was to investigate the disinfection efficacy of ozone (O(3)) and UV-C illumination (UV), and their combination (O(3)-UV) for reducing microbial flora of fresh-cut onion, escarole, carrot, and spinach wash waters collected from the industry. Furthermore, the influence of water physicochemical parameters on the decontamination efficacy and the effect of these technologies on physicochemical quality of wash water were analyzed. O(3), UV, and O(3)-UV were effective disinfection treatments on vegetable wash water, with a maximum microbial reduction of 6.6 log CFU mL(-1) after 60 min treatment with O(3)-UV. However, maximum total microbial reductions achieved by UV and O(3) treatments after 60 min were 4.0 and 5.9 log CFU mL(-1), lower than by O(3)-UV treatment. Furthermore, turbidity of wash water was reduced significantly by O(3) and O(3)-UV treatments, while UV treatment did not affect the physicochemical quality of the water. Conclusions derived from this study illustrate that O(3) and O(3)-UV are alternatives to other sanitizers used in the fresh-cut washing processes. The use of these technologies would allow less frequent changing of spent water and the use of much lower sanitizer doses. Nevertheless, in specific applications such as carrot wash water, where levels of undesirable microbial and chemical constituents are lower than other vegetable wash water, UV treatment could be an appropriate treatment considering cost-effectiveness criteria.

  12. Effects of clove essential oil and eugenol on quality and browning control of fresh-cut lettuce.

    Science.gov (United States)

    Chen, Xiangning; Ren, Lupei; Li, Menglin; Qian, Jia; Fan, Junfeng; Du, Bin

    2017-01-01

    This study confirmed the inhibitory effects of clove essential oil (CEO) and eugenol (EUG) on the browning and relevant enzymes of fresh-cut lettuce, and examined associated mechanisms by inhibition kinetics and computational docking analysis. Fresh-cut lettuce was treated with 0.05% CEO and 0.05% EUG solutions, resulting in inhibition of the deterioration of texture quality and browning of the lettuce surface and interior. Compared with the controls, CEO and EUG significantly inhibited the activities of phenylalanine ammonia lyase (PAL), polyphenol oxidase (PPO), and peroxidase (POD, all p<0.05). EUG suppressed PAL, PPO, and POD in vitro in a dose-dependent manner, with IC50 values of 5.4±0.9, 29.5±3.5, and 61.9±6.7mM, respectively. The binding and inhibition effects of EUG on PAL, PPO, and POD, determined by inhibition kinetics and computational docking analysis, established EUG as a competitive inhibitor of these browning-relevant enzymes.

  13. A single method for recovery and concentration of enteric viruses and bacteria from fresh-cut vegetables.

    Science.gov (United States)

    Sánchez, G; Elizaquível, P; Aznar, R

    2012-01-03

    Fresh-cut vegetables are prone to be contaminated with foodborne pathogens during growth, harvest, transport and further processing and handling. As most of these products are generally eaten raw or mildly treated, there is an increase in the number of outbreaks caused by viruses and bacteria associated with fresh vegetables. Foodborne pathogens are usually present at very low levels and have to be concentrated (i.e. viruses) or enriched (i.e. bacteria) to enhance their detection. With this aim, a rapid concentration method has been developed for the simultaneous recovery of hepatitis A virus (HAV), norovirus (NV), murine norovirus (MNV) as a surrogate for NV, Escherichia coli O157:H7, Listeria monocytogenes and Salmonella enterica. Initial experiments focused on evaluating the elution conditions suitable for virus release from vegetables. Finally, elution with buffered peptone water (BPW), using a Pulsifier, and concentration by polyethylene glycol (PEG) precipitation were the methods selected for the elution and concentration of both, enteric viruses and bacteria, from three different types of fresh-cut vegetables by quantitative PCR (qPCR) using specific primers. The average recoveries from inoculated parsley, spinach and salad, were ca. 9.2%, 43.5%, and 20.7% for NV, MNV, and HAV, respectively. Detection limits were 132 RT-PCR units (PCRU), 1.5 50% tissue culture infectious dose (TCID₅₀), and 6.6 TCID₅₀ for NV, MNV, and HAV, respectively. This protocol resulted in average recoveries of 57.4%, 64.5% and 64.6% in three vegetables for E. coli O157:H7, L. monocytogenes and Salmonella with corresponding detection limits of 10³, 10² and 10³ CFU/g, respectively. Based on these results, it can be concluded that the procedure herein is suitable to recover, detect and quantify enteric viruses and foodborne pathogenic bacteria within 5 h and can be applied for the simultaneous detection of both types of foodborne pathogens in fresh-cut vegetables.

  14. Impacts of sodium chlorite combined with calcium chloride, and calcium ascorbate on microbial population, browning, and quality of fresh-cut rose apple

    Directory of Open Access Journals (Sweden)

    Sunthon Mola

    2016-09-01

    Full Text Available Microbial activity and browning were minimized and fresh-cut rose apple quality was maintained using sodium chlorite (SC combined with calcium chloride (CC and calcium ascorbate (CaAs and by investigating the optimal concentration and dipping time of SC for inhibiting microbial activity and browning. Fresh-cut rose apple samples were dipped in SC solution at 100 mg/L and 200 mg/L for 1 min and 3 min, with filtered water and non-dipped samples as controls. All samples were kept at 4 ± 2 °C for 9 d. The results showed that 200 mg/L SC for 3 min was the best treatment to inhibit microbial growth (total bacteria, yeast and molds, Escherichia coli and coliforms, delay browning and polyphenol oxidase (PPO activity of fresh-cut rose apples, but could not maintain the fresh firmness. A firmness experiment was conducted by dipping fresh-cut rose apples in 200 mg/L SC and in 200 mg/L SC combined with 20 g/L CC and 20 g/L CaAs (SC + CC + CaAs for 3 min before storage at 4 ± 2 °C for 9 d. Samples immersed in filtered water were used as the control. The combined treatment delayed microbial contamination and browning by reducing the PPO activity and the accumulation of phenolic content, and maintained the fresh firmness of fresh-cut rose apples. Thus, the combination treatment of SC + CC + CaAs solution can protect fresh-cut rose apples against microbial contamination and delay browning and maintain firmness.

  15. Enhancing safety and aroma appealing of fresh-cut fruits and vegetables using the antimicrobial and aromatic power of essential oils.

    Science.gov (United States)

    Ayala-Zavala, J Fernando; González-Aguilar, Gustavo A; del-Toro-Sánchez, L

    2009-09-01

    Microbial and aroma attributes are within the most decisive factors limiting safety and sensory appealing of fresh-cut fruits and vegetables. Alternatively, several plant essential oils (EOs) are constituted of several volatile active compounds and most of them present antimicrobial potential and had different aroma profile. Considering these premises, this hypothesis article states that safety and aroma appealing of fresh-cut produce could be improved with EO treatment. EOs could prevent fresh-cut fruit decay; however, their volatile constituents could be sorbed by the produce, and according to the aroma notes of the antimicrobial oil, sensorial appealing of odor, and flavor of the treated produce might be affected positively or negatively. Specifically, garlic oil is a natural antimicrobial constituted by sulfur compounds, which are responsible for its odor and antimicrobial properties. Besides, fresh-cut tomato is a highly perishable product that needs antimicrobial agents to preserve its quality and safety for a longer period of time. From the sensorial point of view, aroma combination of garlic and tomato is a common seasoning practice in Europe and America and well accepted by consumers. Once the right combination of flavors between the EOs and the fresh-cut produce has been selected, safety and quality of the treated fruit could be improved by adding antimicrobial protection and extra aroma. Therefore, other combinations between EOs and fresh-cut produce are discussed. This approximation could reinforce the trends of natural food preservation, accomplishing the demands of the increasing sector of consumers demanding tasty and convenient fresh-cut produce, containing only natural ingredients.

  16. Improved quality of a vitamin B12-fortified 'ready to blend' fresh-cut mix salad with chitosan.

    Science.gov (United States)

    Artés-Hernández, Francisco; Formica-Oliveira, Anna Carolina; Artés, Francisco; Martínez-Hernández, Ginés Benito

    2017-01-01

    A vitamin B12-fortified (0.25 mg L(-1)) chitosan (10 g L(-1)) coating was applied to a ready-to-blend fresh-cut salad including melon, pineapple and carrot, which was stored at 5 ℃ up to nine days. Uncoated samples were used as control while the vitamin B12 effect was compared to non-fortified chitosan-coated samples. Beverages were prepared on blending days 0, 4, 7 and 9 with subsequent storage at 5 ℃ for 0, 24 and 48 h. Physicochemical quality of fresh blended beverages was well preserved throughout storage. The chitosan coating highly reduced epiphytic microflora growth and polyphenoloxidase/peroxidase activities. No relevant variations of total phenolic contents were observed between different fresh blended beverages. However, its total antioxidant capacity reported after blending was lower as storage time of ready-to-blend samples increased. Fortified samples showed a vitamin B12 content of 8.6 µg kg(-1) on processing day, ensuring 200 mL of such beverage the recommended daily intake of this vitamin. In conclusion, a ready-to-blend fruit/vegetable mix, fortified with vitamin B12, was developed with a shelf life of nine days at 5 ℃ showing the prepared beverages good quality during subsequent storage for 48 h at 5 ℃.

  17. Survival and Growth of Listeria monocytogenes on Fresh-Cut "Athena" and "Rocky Ford" Cantaloupes During Storage at 4°C and 10°C.

    Science.gov (United States)

    Nyarko, Esmond; Kniel, Kalmia E; Reynnells, Russell; East, Cheryl; Handy, Eric T; Luo, Yaguang; Millner, Patricia D; Sharma, Manan

    2016-11-01

    Cantaloupes, marketed as "Rocky Ford," were implicated in the U.S. multistate outbreak of listeriosis in 2011, which caused multiple fatalities. Listeria monocytogenes can survive on whole cantaloupes and can be transferred to the flesh of melons. The growth of L. monocytogenes on fresh-cut "Athena" and "Rocky Ford" cantaloupe cultivars during refrigerated storage was evaluated. Fresh-cut cubes (16.4 cm(3)) from field-grown cantaloupes were each inoculated with 5 log10 CFU/mL of a multi-strain mixture of L. monocytogenes and stored at 4°C or 10°C. Inoculated fresh-cut cubes were also: (1) continuously stored at 4°C for 3 days; (2) temperature-abused (TA: 25°C for 4 h) on day 0; or (3) stored at 4°C for 24 h, exposed to TA on day 1, and subsequently stored at 4°C until day 3. L. monocytogenes populations on fresh-cut melons continuously stored at 4°C or 10°C were enumerated on selected days for up to 15 days and after each TA event. Brix values for each cantaloupe variety were determined. L. monocytogenes populations on fresh-cut cantaloupe cubes stored at 4°C increased by 1.0 and 3.0 log10 CFU/cube by day 7 and 15, respectively, whereas those stored at 10°C increased by 3.0 log10 CFU/cube by day 7. Populations of L. monocytogenes on fresh-cut cantaloupes stored at 10°C were significantly (p fresh-cut "Athena" and "Rocky Ford" cubes, even though "Athena" cubes had significantly higher Brix values than the "Rocky Ford" fruit. L. monocytogenes populations on fresh-cut cantaloupes exposed to TA on day 1 and then refrigerated were significantly greater (0.74 log10 CFU) than those stored continuously at 4°C for 3 days. Storage at 10°C or exposure to TA events promoted growth of L. monocytogenes on fresh-cut cantaloupe during refrigerated storage.

  18. Effect of cut type on fresh-cut 'menina brasileira' zucchini quality Efeito do tipo de corte na qualidade de abobrinha 'Menina Brasileira' minimamente processada

    Directory of Open Access Journals (Sweden)

    Brígida Monteiro Vilas Boas

    2011-12-01

    Full Text Available Market sales of ready-to-use fresh fruit and vegetables have grown quickly in the recent years as a result of changes in consumer attitudes. The goal of this work was to evaluate the effect of two kinds of cuts on the physiological, physical, physical-chemical, chemical and biochemical traits of fresh-cut 'Menina Brasileira' zucchini stored in rigid polypropylene packages, with lids of the same material containing sliced and grated zucchini and stored at 5º C, for 15 days. The variables respiratory rate, pH, L* value, soluble pectin, PME and PG activity, was interactively affected by the cut type and storage time factors. The variables mass loss, phenylalanine ammonia-lyase activity and total pectin variable were only significantly affected by storage time factor. It can be concluded that sliced 'Menina Brasileira' zucchini shows a higher titratable acidity and soluble solids and a lower respiratory rate, pectin soluble and phenylalanine ammonia-lyase activity when compared with grated zucchini, contributing to the preservation of quality attributes.As vendas no mercado de frutas e hortaliças frescas prontas para o consumo têm crescido rapidamente nos últimos anos como resultado de mudanças nas atitudes dos consumidores. Neste trabalho objetivou-se avaliar o efeito de dois tipos de cortes nas características fisiológicas, físicas, químicas, físico-químicas e bioquímicas de abobrinha 'Menina Brasileira' minimamente processada, armazenada a 5º C em embalagens de polipropileno rígido, com tampas do mesmo material, contendo abobrinha fatiada e ralada, por 15 dias. As variáveis taxas respiratórias, pH, valor L*, pectina solúvel, atividade de PME e PG, foram interativamente afetadas pelos fatores tipo de corte e tempo de armazenamento. As variáveis perda de massa, atividade da fenilalanina amônia-liase e a pectina total foram afetadas significativamente apenas pelo fator tempo de armazenamento. Pode-se concluir que a abobrinha

  19. Efeito do tipo de corte e de sanificantes no escurecimento de pequi minimamente processado Effect of cutting type and sanitizers on the browning of fresh cut peki fruit

    Directory of Open Access Journals (Sweden)

    Luiz José Rodrigues

    2011-06-01

    Full Text Available Conduziu-se este trabalho, com o objetivo de avaliar a influência dos sanificantes hipoclorito de sódio (NaClO e de peróxido de hidrogênio (H2O2 em diferentes concentrações sobre a vida de prateleira de pequi (Caryocar brasilense Cambess. submetido a dois tipos de processamento mínimo: "caroço fatiado" e "caroço inteiro", e armazenados a 6 ± 1° C e 90 a 95% UR, durante 15 dias. O experimento foi conduzido em delineamento inteiramente casualizado, disposto em um fatorial 2 x 6 x 5, ou seja, 2 tipos de processamento (caroços "fatiados" e "inteiros", 6 tempos (0h, 3, 6, 9, 12, 15 dias e 5 tratamentos (controle, NaClO 50 ppm, NaClO 100 ppm, H2O2 4% e H2O2 6%, com 3 repetições. A cada três dias foram realizadas as análises: vitamina C, polifenoloxidase, peroxidase e cor (CIE L*a*b*. O pequi minimamente processado apresentou decréscimo nos teores de vitamina C ao longo do armazenamento. O caroço fatiado mostrou-se com maior atividade da enzima polifenoloxidase em relação ao inteiro. A interação significativa entre o corte, o sanificante e o tempo ocorreu para a variável peroxidase, tendo sido observado para o caroço fatiado tratado com os sanificantes H2O2 4 e 6% maior atividade dessa enzima. Observou-se a redução do valor de L*, durante o armazenamento do pequi minimamente processado, independente do sanificante utilizado, ocasionado pelo escurecimento do produto.The objective of the present work was to evaluate the influence of the sanitizers sodium hypochlorite (NaClO 50 and 100 ppm and 4% and 6%, hydrogen peroxide (H2O2 on the shelf life of fresh cut peki fruit (Caryocar brasilense Cambess. submitted to two sorts of processing: "sliced stone" and whole stone", stored at 6 ± 1° C and 90 to 95% of RH for 15 days. The analyses were performed every three days. The experiment was conducted in a completely randomized design arranged by a 2 x 6 x 5 factorial, i.e. 2 sorts of processing ("sliced and whole stones", 6 times (0h

  20. Quality index, consumer acceptability, bioactive compounds, and antioxidant activity of fresh-cut "ataulfo" mangoes (mangifera indica L.) as affected by low-temperature storage.

    Science.gov (United States)

    Robles-Sánchez, R M; Islas-Osuna, M A; Astiazarán-García, H; Vázquez-Ortiz, F A; Martín-Belloso, O; Gorinstein, S; González-Aguilar, G A

    2009-04-01

    To measure bioactive compound losses due to minimal processing, mature green fresh-cut mangoes (Mangifera indica L.) cv. "Ataulfo" were subjected to an antioxidant treatment and stored at 5 degrees C during 15 d. Quality index, total phenols, flavonoids, beta-carotene, ascorbic acid, vitamin E, and antioxidant activity were measured during the storage period of fruits. Antioxidant capacity was estimated using ORAC(FL), TEAC, and DPPH assays. The dipping treatments with ascorbic acid (AA) + citric acid (CA) + CaCl2 affected positively quality delaying deterioration of fresh-cut mango as compared with whole fruit. However, dipping treatment affected the consumer preferences of fresh-cut mangoes. The highest vitamin C, beta-carotene, and vitamin E losses were observed after 10 d, being similar in whole and fresh-cut mangoes. The antioxidant activity was not significantly affected by storage time. We conclude that fresh-cut mangoes retained their bioactive compound content during storage and their antioxidant and nutritional properties make them a good source of these compounds.

  1. Predictive modeling for growth of non- and cold-adapted Listeria monocytogenes on fresh-cut cantaloupe at different storage temperatures.

    Science.gov (United States)

    Hong, Yoon-Ki; Yoon, Won Byong; Huang, Lihan; Yuk, Hyun-Gyun

    2014-06-01

    The aim of this study was to determine the growth kinetics of Listeria monocytogenes, with and without cold-adaption, on fresh-cut cantaloupe under different storage temperatures. Fresh-cut samples, spot inoculated with a 4-strain cocktail of L. monocytogenes (∼3.2 log CFU/g), were exposed to constant storage temperatures held at 10, 15, 20, 25, or 30 °C. All growth curves of L. monocytogenes were fitted to the Baranyi, modified Gompertz, and Huang models. Regardless of conditions under which cells grew, the time needed to reach 5 log CFU/g decreased with the elevated storage temperature. Experimental results showed that there were no significant differences (P > 0.05) in the maximum growth rate k (log CFU/g h(-1) ) and lag phase duration λ (h) between the cultures of L. monocytogenes with or without previous cold-adaption treatments. No distinct difference was observed in the growth pattern among 3 primary models at various storage temperatures. The growth curves of secondary modeling were fitted on an Arrhenius-type model for describing the relationship between k and temperature of the L. monocytogenes on fresh-cut cantaloupe from 10 to 30 °C. The root mean square error values of secondary models for non- and cold-adapted cells were 0.018, 0.021, and 0.024, and 0.039, 0.026, and 0.017 at the modified Gompertz, Baranyi, and Huang model, respectively, indicating that these 3 models presented the good statistical fit. This study may provide valuable information to predict the growth of L. monocytogenes on fresh-cut cantaloupes at different storage conditions. Listeriosis has occurred and increased along with the increased demand of fresh and fresh-cut fruits and vegetables. This study was conducted to predict the growth of non- and cold-adapted L. monocytogenes on fresh-cut cantaloupe at different temperature using mathematical model. These results can be helpful for risk assessments of L. monocytogenes in fresh-cut cantaloupe. This study provides valuable

  2. Salicylic acid inhibits enzymatic browning of fresh-cut Chinese chestnut (Castanea mollissima) by competitively inhibiting polyphenol oxidase.

    Science.gov (United States)

    Zhou, Dan; Li, Lin; Wu, Yanwen; Fan, Junfeng; Ouyang, Jie

    2015-03-15

    The inhibitory effect and associated mechanisms of salicylic acid (SA) on the browning of fresh-cut Chinese chestnut were investigated. Shelled and sliced chestnuts were immersed in different concentrations of an SA solution, and the browning of the chestnut surface and interior were inhibited. The activities of polyphenol oxidase (PPO) and peroxidase (POD) extracted from chestnuts were measured in the presence and absence of SA. SA at concentrations higher than 0.3g/L delayed chestnut browning by significantly inhibiting the PPO activity (P0.05). The binding and inhibition modes of SA with PPO and POD, determined by AUTODOCK 4.2 and Lineweaver-Burk plots, respectively, established SA as a competitive inhibitor of PPO.

  3. Nutrient solution aeration and growing cycles affect quality and yield of fresh-cut baby leaf red lettuce

    Directory of Open Access Journals (Sweden)

    Encarnación Conesa

    2015-12-01

    Full Text Available The objective of this research was to study the effects of nutrient solution aeration [no aeration (NA, low aeration (LA or high aeration (HA] and growing cycle (autumn, winter and summer on the yield, quality, and shelf life of red lettuce as a fresh-cut product grown in a floating system. The specific leaf area, yield and root diameter were affected by the growing cycle. The percentage of dry matter and the nitrate content were affected by growing cycle and aeration, total phenolics and mesophilic microorganism by aeration and storage time, hue angle and chromacity by growing cycle and storage time, and antioxidant capacity, vitamin C, lightness and psychrophilic microorganisms were affected by all three factors. NA conditions increased the antioxidant capacity in summer and vitamin C content in winter. The lowest mesophilic and psychrophilic count was observed in autumn. The effect of aeration on most of the quality parameters measured was influenced by the growing cycle.

  4. [Effect of blanching and hygroscopic coating on quality of fresh cut carrots (Daucus carota var. chantenay) during storage].

    Science.gov (United States)

    Uquiche Carrasco, Edgar; Cisneros-Zevallos, Luis

    2002-06-01

    The effect of blanching at low temperatures (solution 1% acid citric, 50 degrees C for 30 seconds) and the application of glycerol as humectant (3% p/p, 20 seconds) to preserve the quality of fresh-cut carrots (Daucus carota) were studied as individual or combined treatments. Four treatments were evaluated: a control by dipping samples for 30 seconds in distilled water (T1); blanching (T2); glycerol application (T3); and blanching plus glycerol application (T4). Total carotenoids content, color, soluble solids and weight loss were monitored during storage. Results showed no differences between treatments in carotenoids content (p > 0.10) and soluble solids (p > 0.05). However, differences were observed between treatments in weight loss (p Blanched samples (T2 and T4) showed small changes in orange color intensity compared to treatments T1 and T3 (p < 0.05).

  5. Gas permeability and thermal behavior of polypropylene films used for packaging minimally processed fresh-cut potatoes: a case study.

    Science.gov (United States)

    Siracusa, Valentina; Blanco, Ignazio; Romani, Santina; Tylewicz, Urszula; Dalla Rosa, Marco

    2012-10-01

    This work reports an experimental study on the permeability and thermal behavior of commercial polypropylene (PP) film used for fresh-cut potatoes packaging. The permeability was tested using oxygen, carbon dioxide, nitrogen, mix of these 3 gases, normally used for modified atmosphere packaging (MAP) and Air, to understand if it would be possible to extend the shelf life of this food product designed for the catering field in respect to the packaging behavior. The temperature influence on permeability data, from 5 to 40 °C, was analyzed, before and after 4, 8, 12, 15, and 20 d of food contact, pointing out the dependence between temperature and gas transmission rate (GTR), solubility (S), diffusion coefficient (D), and time lag (t(L)) parameters. The activation energies (E) of the permeation process were determined with the different gases used in the experiments. The thermal behavior of PP film was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) to well understand its thermal stability. Fourier transformed-infrared with attenuated total reflectance (FT-IR/ATR) spectroscopy was also performed in order to study the influence of the food contact on the chemical characteristics of the polymer film. The results obtained were discussed and compared each other. Studied samples showed, for all investigated gases, an increase of gas permeability and S values at higher temperature. Heat resistance classification among the sample as it is and stored in modified atmospheres was made. Finally all performed experiments have showed good polymer stability for the shelf-life storage potatoes under study. Study of packaging material was performed in a range of temperature, which can simulate the service condition to assess the suitability of a commercial polymer film for modified atmosphere packaging of fresh-cut potatoes minimally processed designed for catering purpose. © 2012 Institute of Food Technologists®

  6. Effect of high oxygen and high carbon dioxide atmosphere packaging on the microbial spoilage and shelf-life of fresh-cut honeydew melon.

    Science.gov (United States)

    Zhang, Bao-Yu; Samapundo, Simbarashe; Pothakos, Vasileios; Sürengil, Göknur; Devlieghere, Frank

    2013-09-16

    This study evaluated the potential of modified atmospheres (MAs) combining high oxygen (O₂) and high carbon dioxide (CO₂) levels to extend the shelf-life of fresh-cut honeydew melon. Firstly, the effect of MA on the growth and volatile organic metabolite production of Candida sake, Leuconostoc mesenteroides and Leuconostoc gelidum, which had all been previously isolated from spoiled commercial fresh-cut honeydew melon, was evaluated separately on honeydew melon agar at 7 °C. Additionally, the effect of selected MAs on the microbial, physico-chemical and sensory quality of commercial fresh-cut honeydew melon cubes was evaluated at 7 °C. The results showed that MAs with high O₂ and high CO₂ levels greatly retarded the growth, CO₂ and volatile metabolite production (i.e. ethanol, 2-methyl-1-butanol, ethyl acetate, phenylacetic acid, nonanal) of C. sake on honeydew melon agar; especially MAs consisting of 50% O₂+50% CO₂ and 70% O₂+30% CO₂. In contrast, the MAs evaluated only had a minor effect on the growth and volatile metabolite production of L. mesenteroides and L. gelidum. Overall, the effect of MAs on colour, juice leakage, juiciness, and firmness of fresh-cut honeydew melon was small during storage. Sensory preference was generally for fresh-cut honeydew melon cubes packaged in MA of 50% O₂+50% CO₂. These were still acceptable on day five of storage and had appreciably lower populations of yeasts and lactic acid bacteria, lower quantities of volatile organic compounds, but slightly stronger colour oxidation compared to honeydew melon that was packaged in air. Additionally, most of the samples packed in air had blown by day five due to the large quantity of CO₂ production during storage. Therefore, 50% O₂+50% CO₂ is a potential MA solution for extending the shelf-life of fresh-cut honeydew melon.

  7. Effect of native microflora, waiting period, and storage temperature on Listeria monocytogenes serovars transferred from cantaloupe rind to fresh-cut pieces during preparation.

    Science.gov (United States)

    Ukuku, Dike O; Olanya, Modesto; Geveke, David J; Sommers, Christopher H

    2012-11-01

    The most recent outbreak of listeriosis linked to consumption of fresh-cut cantaloupes indicates the need to investigate the behavior of Listeria monocytogenes in the presence of native microflora of cantaloupe pieces during storage. Whole cantaloupes were inoculated with L. monocytogenes (10(8)-CFU/ml suspension) for 10 min and air dried in a biosafety cabinet for 1 h and then treated (unwashed, water washed, and 2.5% hydrogen peroxide washed). Fresh-cut pieces (∼3 cm) prepared from these melons were left at 5 and 10°C for 72 h and room temperature (20°C) for 48 h. Some fresh-cut pieces were left at 20°C for 2 and 4 h and then refrigerated at 5°C. Microbial populations of fresh-cut pieces were determined by the plate count method or enrichment method immediately after preparation. Aerobic mesophilic bacteria, yeast and mold of whole melon, and inoculated populations of L. monocytogenes on cantaloupe rind surfaces averaged 6.4, 3.3, and 4.6 log CFU/cm(2), respectively. Only H(2)O(2) (2.5%) treatment reduced the aerobic mesophilic bacteria, yeast and mold, and L. monocytogenes populations to 3.8, 0.9, and 1.8 log CFU/cm(2), respectively. The populations of L. monocytogenes transferred from melon rinds to fresh-cut pieces were below detection but were present by enrichment. Increased storage temperatures enhanced the lag phases and growth of L. monocytogenes. The results of this study confirmed the need to store fresh-cut cantaloupes at 5°C immediately after preparation to enhance the microbial safety of the fruit.

  8. Short UV-C Treatment Prevents Browning and Extends the Shelf-Life of Fresh-Cut Carambola

    Directory of Open Access Journals (Sweden)

    Carlota Moreno

    2017-01-01

    Full Text Available In this work, we selected a short UV-C treatment for fresh-cut carambola and assessed its efficacy in supplementing the benefits of low temperature storage. UV-C treated (6.0, 10.0, and 12.5 kJ m−2 carambola slices showed reduced deterioration compared to control fruit. Treatment with a dose of 12.5 kJ m−2 UV-C was more effective in maintaining quality and was selected for subsequent experiments evaluating the combination of UV-C and refrigeration on fruit storability and physical, chemical, and microbiological properties. Short UV-C exposure reduced weight loss and electrolyte leakage. UV-C treated carambola slices presented higher phenolic antioxidants than control after 21 d at 4°C and showed no alterations in soluble solids or titratable acidity. UV-C exposure also reduced the counts of molds, yeast, and aerobic mesophilic bacteria. UV-C treated fruit showed a fresh-like appearance even after 21 d as opposed to control carambola which presented spoilage and extensive browning symptoms. The reduction of fruit browning in UV-C treated fruit was not due to reduction in phenylalanine-ammonia lyase (PAL and/or peroxidase (POD, but rather through polyphenol oxidase (PPO inhibition and improved maintenance of tissue integrity.

  9. Effects of pulsed light treatments and pectin edible coatings on the quality of fresh-cut apples: a hurdle technology approach.

    Science.gov (United States)

    Moreira, María R; Álvarez, María V; Martín-Belloso, Olga; Soliva-Fortuny, Robert

    2017-01-01

    Pulsed light (PL) treatments stand as an alternative for the shelf-life extension of fresh-cut products. The antimicrobial effects of PL are well known; however, its influence on quality attributes needs to be assessed. This study was aimed at evaluating the application of PL treatments in combination with pectin-based edible coatings enriched with dietary fiber for the preservation of fresh-cut apples. Dipping of fresh-cut apples in ascorbic acid/calcium chloride solution prior to pectin coating and PL treatments was effective to minimize browning and softening of apple surfaces. Incorporation of fiber in the pectin coating did not cause any change in microbial loads and sensory acceptability of apple cubes. Pectin-coated PL-treated apple pieces exhibited significantly higher antioxidant activity values than fresh and PL control samples. At the end of storage, the combination of both treatments resulted in an almost 2 log CFU g(-1) reduction of microbial counts. Sensory attribute scores did not fall below the rejection limit throughout 14 days, although the presence of off-odors limited the acceptability of the pectin-coated samples. The results demonstrate that PL treatments applied to pectin-coated fresh-cut apples may be used to maintain quality attributes, thus conferring prebiotic potential and extending the shelf-life of the product. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  10. Total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh-cut mango (Mangifera indica L., cv. Tommy Atkin) as affected by infrared heat treatment.

    Science.gov (United States)

    Sogi, D S; Siddiq, M; Roidoung, S; Dolan, K D

    2012-11-01

    Mango (Mangifera indica L.) is a major tropical fruit that has not been exploited for fresh-cut or minimally processed products on a scale similar to apples, pineapples, or melons. The objective of this study was to investigate the effect of infrared (IR) treatment on total phenolics, carotenoids, ascorbic acid, and antioxidant properties of fresh-cut cubes from 'Tommy Atkin' mangoes. Mango cubes were IR treated (5, 10, 15 min) and evaluated at 4-d intervals during 16-d storage at 4 ± 1 °C. Total phenolics, carotenoids, and ascorbic acid content in fresh-cut control mango cubes were 43.33, 1.37, and 15.97 mg/100 g FW, respectively. IR treatments increased total phenolics (59.23 to 71.16 mg/100 g FW) and decreased ascorbic acid (12.14 to 15.38 mg/100 g, FW). Total carotenoids showed a mixed trend (1.13 to 1.66 mg/100 g, FW). The IR treatment showed a significant positive impact on antioxidant properties (μM TE/100 g, FW) of mango cubes, as assayed by ABTS (261.5 compared with 338.0 to 416.4), DPPH (270.5 compared with 289.4 to 360.5), and ORAC (6686 compared with 8450 to 12230). Total phenolics, carotenoids, ascorbic acid, and antioxidant capacity decreased over 16-d storage. However, IR treated samples had consistently higher ABTS, DPPH, and total phenolics during storage. It was demonstrated that IR treatment can be effectively used in improving antioxidant properties of fresh-cut mangoes with minimal effect on the visual appearance. Various methods/treatments are in use for extending the quality of fresh-cut fruits, including mild heat treatment. This study explored the application of infrared (IR) heat for processing fresh-cut mango cubes and evaluated its effect on vitamin C and antioxidant capacity during 16-d storage. This is the first study reporting on the use of IR heat in fresh-cut fruits. IR treatment was shown to be effective in retaining antioxidant properties of fresh-cut mango cubes with minimal effect on the visual appearance. © 2012 Institute

  11. Efficacy of Sanitizer Treatments on Survival and Growth Parameters of Escherichia coli O157:H7, Salmonella, and Listeria monocytogenes on Fresh-Cut Pieces of Cantaloupe during Storage.

    Science.gov (United States)

    Ukuku, Dike O; Huang, Lihan; Sommers, Christopher

    2015-07-01

    For health reasons, people are consuming fresh-cut fruits with or without minimal processing and, thereby, exposing themselves to the risk of foodborne illness if such fruits are contaminated with bacterial pathogens. This study investigated survival and growth parameters of Escherichia coli O157:H7, Salmonella, Listeria monocytogenes, and aerobic mesophilic bacteria transferred from cantaloupe rind surfaces to fresh-cut pieces during fresh-cut preparation. All human bacterial pathogens inoculated on cantaloupe rind surfaces averaged ∼4.8 log CFU/cm(2), and the populations transferred to fresh-cut pieces before washing treatments ranged from 3 to 3.5 log CFU/g for all pathogens. A nisin-based sanitizer developed in our laboratory and chlorinated water at 1,000 mg/liter were evaluated for effectiveness in minimizing transfer of bacterial populations from cantaloupe rind surface to fresh-cut pieces. Inoculated and uninoculated cantaloupes were washed for 5 min before fresh-cut preparation and storage of fresh-cut pieces at 5 and 10°C for 15 days and at 22°C for 24 h. In fresh-cut pieces from cantaloupe washed with chlorinated water, only Salmonella was found (0.9 log CFU/g), whereas E. coli O157:H7 and L. monocytogenes were positive only by enrichment. The nisin-based sanitizer prevented transfer of human bacteria from melon rind surfaces to fresh-cut pieces, and the populations in fresh-cut pieces were below detection even by enrichment. Storage temperature affected survival and the growth rate for each type of bacteria on fresh-cut cantaloupe. Specific growth rates of E. coli O157:H7, Salmonella, and L. monocytogenes in fresh-cut pieces were similar, whereas the aerobic mesophilic bacteria grew 60 to 80 % faster and had shorter lag phases.

  12. Measurement of Multiple Vitamin K Forms in Processed and Fresh-Cut Pork Products in the U.S. Food Supply.

    Science.gov (United States)

    Fu, Xueyan; Shen, Xiaohua; Finnan, Emily G; Haytowitz, David B; Booth, Sarah L

    2016-06-01

    Vitamin K food composition data have historically been limited to plant-based phylloquinone (vitamin K1). The purpose of this study was to expand analysis of vitamin K to animal products and to measure phylloquinone and 10 forms of menaquinones (vitamin K2) in processed and fresh-cut pork products. Nationally representative samples of processed pork products (n = 28) were obtained through USDA's National Food and Nutrition Analysis Program, and fresh pork (six cuts; n = 5 per cut) and bacon (n = 4) were purchased from local retail outlets. All samples were analyzed by high-performance liquid chromatography (phylloquinone and menaquinone-4) and atmospheric-pressure chemical ionization-liquid chromatography-mass spectrometry (menaquinone-5 to menaquinone-13). Although low in phylloquinone (processed pork products and fresh pork cuts contained menaquinone-4, menaquinone-10, and menaquinone-11 (range: [35.1 ± 11.0]-[534 ± 89.0] μg of menaquinones per 100 g). The total menaquinone contents of processed pork products were correlated with fat contents (r = 0.935). In summary, processed and fresh-cut pork products are a rich dietary source of menaquinones that are currently unaccounted for in assessment of vitamin K in the food supply.

  13. Shelf-life prediction models for ready-to-eat fresh cut salads: Testing in real cold chain.

    Science.gov (United States)

    Tsironi, Theofania; Dermesonlouoglou, Efimia; Giannoglou, Marianna; Gogou, Eleni; Katsaros, George; Taoukis, Petros

    2017-01-02

    The aim of the study was to develop and test the applicability of predictive models for shelf-life estimation of ready-to-eat (RTE) fresh cut salads in realistic distribution temperature conditions in the food supply chain. A systematic kinetic study of quality loss of RTE mixed salad (lollo rosso lettuce-40%, lollo verde lettuce-45%, rocket-15%) packed under modified atmospheres (3% O2, 10% CO2, 87% N2) was conducted. Microbial population (total viable count, Pseudomonas spp., lactic acid bacteria), vitamin C, colour and texture were the measured quality parameters. Kinetic models for these indices were developed to determine the quality loss and calculate product remaining shelf-life (SLR). Storage experiments were conducted at isothermal (2.5-15°C) and non-isothermal temperature conditions (Teff=7.8°C defined as the constant temperature that results in the same quality value as the variable temperature distribution) for validation purposes. Pseudomonas dominated spoilage, followed by browning and chemical changes. The end of shelf-life correlated with a Pseudomonas spp. level of 8 log(cfu/g), and 20% loss of the initial vitamin C content. The effect of temperature on these quality parameters was expressed by the Arrhenius equation; activation energy (Ea) value was 69.1 and 122.6kJ/mol for Pseudomonas spp. growth and vitamin C loss rates, respectively. Shelf-life prediction models were also validated in real cold chain conditions (including the stages of transport to and storage at retail distribution center, transport to and display at 7 retail stores, transport to and storage in domestic refrigerators). The quality level and SLR estimated after 2-3days of domestic storage (time of consumption) ranged between 1 and 8days at 4°C and was predicted within satisfactory statistical error by the kinetic models. Teff in the cold chain ranged between 3.7 and 8.3°C. Using the validated models, SLR of RTE fresh cut salad can be estimated at any point of the cold chain

  14. Combination of hot-water surface pasteurization of whole fruit and low-dose gamma irradiation of fresh-cut cantaloupe.

    Science.gov (United States)

    Fan, Xuetong; Annous, Bassam A; Sokorai, Kimberly J B; Burke, Angela; Mattheis, James P

    2006-04-01

    Improvements in methods for disinfecting fresh-cut cantaloupe could reduce spoilage losses and reduce the risk of foodborne illness from human pathogen contamination. The objective of this study was to investigate the feasibility of using hot-water treatment in combination with low-dose irradiation to reduce native microbial populations while maintaining the quality of fresh-cut cantaloupe. Whole cantaloupes were washed in tap water at 20 or 76 degrees C for 3 min. Fresh-cut cantaloupe cubes, prepared from the washed fruit, were then packaged in clamshell containers, and half the samples were exposed to 0.5 kGy of gamma radiation. Native microflora populations and sensory qualities were evaluated during the subsequent 7 days of storage at 4 degrees C. The hot-water surface pasteurization reduced the microflora population by 3.3 log on the surface of whole fruits, resulting in a lower microbial load on the fresh-cut cubes compared with cubes cut from fruit treated with cold water. Irradiation of cubes prepared from untreated fruit to an absorbed dose of 0.5 kGy achieved a low microbial load similar to that of cubes prepared from hot-water-treated fruit. The combination of the two treatments was able to further reduce the microflora population. During storage, the headspace atmosphere of the packages was not significantly influenced by any of the treatments. Color, titratable acidity, pH, ascorbic acid, firmness, and drip loss were not consistently affected by treatment with irradiation, hot water, or the combination of the two. Cubes prepared from hot-water-treated whole fruit had slightly lower soluble solids content. The combination of hot-water pasteurization of whole cantaloupe and low-dose irradiation of packaged fresh-cut melon can reduce the population of native microflora while maintaining the quality of this product.

  15. Cutting

    Science.gov (United States)

    ... a traumatic experience, such as living through abuse , violence, or a disaster. Self-injury may feel like ... embarrassed." Sometimes self-injury affects a person's body image. Jen says, "I actually liked how the cuts ...

  16. Effect of Chlorine Dioxide and Ascorbic Acid on Enzymatic Browning and Shelf Life of Fresh-Cut Red Delicious and Granny Smith Apples

    NARCIS (Netherlands)

    Remorini, Damiano; Landi, Marco; Tardelli, Francesca; Lugani, Arianna; Massai, Rossano; Graziani, Giulia; Fogliano, Vincenzo; Guidi, Lucia

    2015-01-01

    In this work, we tested the hypothesis that ascorbic acid (AA) reduces browning of fresh-cut apples (Red Delicious, RD, and Granny Smith, GS), and we investigated the impact of AA on phenylpropanoid metabolism of RD and GS. Apple slices were dipped in a solution of 100mg/L of chlorine dioxide (Cl

  17. Low intensity monochromatic red, blue or green light increases the carbohydrate levels and substantially extends the shelf life of fresh-cut lettuce

    NARCIS (Netherlands)

    Woltering, E.J.; Seifu, Y.W.

    2015-01-01

    During dark storage of fresh-cut product prepared from butterhead and iceberg lettuce the levels of carbohydrates (glucose, fructose, sucrose, starch) decrease. Carbohydrate levels were low in butterhead lettuce at the start [~20 mg/g dry matter (DW)] and levels decreased by over 50% during storage

  18. Survival and growth of Listeria monocytogenes on fresh-cut ‘Athena’ and ‘Rocky Ford’ cantaloupes during storage at 4 and 10°C

    Science.gov (United States)

    Cantaloupes, marketed as ‘Rocky Ford’, were implicated in the fatal U.S. multi-state outbreak of listeriosis in 2011. Listeria monocytogenes can survive on whole cantaloupes and can be transferred to the flesh of melons. The growth of L. monocytogenes on fresh-cut ‘Athena’ and ‘Rocky Ford’ cantaloup...

  19. Combination of sodium chlorite and calcium propionate reduces enzymatic browning and microbial population of fresh-cut ‘Granny Smith’ apples

    Science.gov (United States)

    Tissue browning and microbial growth are the main concerns associated with fresh-cut apples. In this study, effects of sodium chlorite (SC) and calcium propionate (CP), individually and combined, on quality and microbial population of apple slices were investigated. ‘Granny Smith’ apple slices, dipp...

  20. Combined effects of sodium chlorite dip treatment and chitosan coatings on the quality of fresh-cut d’Anjou pears

    Science.gov (United States)

    This study evaluated the effects of sodium chlorite (SC) alone and its sequential treatment with edible coatings on browning inhibition and quality maintenance of fresh-cut d’Anjou pears. Edible coatings were prepared from chitosan (CH) and its water soluble derivative: carboxymethyl chitosan (CMCH...

  1. Nitric oxide prevents wound-induced browning and delays senescence through inhibition of hydrogen peroxide accumulation in fresh-cut lettuce

    NARCIS (Netherlands)

    Iakimova, E.T.; Woltering, E.J.

    2015-01-01

    As a source of bioactive ingredients, lettuce is a preferable component of a healthy diet. In recent years the production of fresh-cut produce has become a fast growing business. However, the shreds are highly sensitive to wound-induced browning and premature senescence that substantially reduces th

  2. 鲜切果蔬包装的研究现状与进展%Advance in packaging of fresh-cut fruit and vegetables

    Institute of Scientific and Technical Information of China (English)

    孙炳新; 杨金玲; 赵宏侠; 王晶晶; 吕长鑫; 冯叙桥

    2013-01-01

    Packaging plays an important role in maintaining the quality of,and extending the shelf life of fresh-cut fruit and vegetables.Advance in the studies and applications of packaging materials in relation with the packaging of fresh-cut fruit and vegetables in the last few years was reviewed and their development envisioned. Packaging technologies of fresh-cut fruit and vegetables were introduced, including the gas adjustment packaging,coating packing and intelligent packaging, and the advantages and disadvantages and application status were summarized.At last, the fresh - cut fruit and vegetables packaging development trends in the future were discussed.%包装在维持鲜切果蔬品质、延长货架寿命等方面发挥着重要的作用.本文综述了近年来国内外包装材料在鲜切果蔬保鲜方面的研究进展与应用.介绍了鲜切果蔬的包装技术,包括气调包装、涂膜包装和智能包装等,总结了其优缺点及应用现状,并且讨论了鲜切果蔬包装未来的发展趋势.

  3. Organic acids produced by lactic acid bacteria (Leuconostoc sp.) contribute to sensorial quality loss in modified-atmosphere-packed fresh-cut iceberg lettuce

    NARCIS (Netherlands)

    Paillart, M.J.M.; Vossen, van der J.M.B.M.; Lommen, E.; Levin, E.; Otma, E.C.; Snels, J.C.M.A.; Woltering, E.J.

    2016-01-01

    The shelf-life of fresh-cut lettuce packed in a modified atmosphere (MA) is determined by its "overall visual quality" (OVQ), being a measure of its general appearance based on colour and shape criteria. In addition to the OVQ, the development of off-flavour and acid off-smell reduces consumer ac

  4. Effect of Chlorine Dioxide and Ascorbic Acid on Enzymatic Browning and Shelf Life of Fresh-Cut Red Delicious and Granny Smith Apples

    NARCIS (Netherlands)

    Remorini, Damiano; Landi, Marco; Tardelli, Francesca; Lugani, Arianna; Massai, Rossano; Graziani, Giulia; Fogliano, Vincenzo; Guidi, Lucia

    2015-01-01

    In this work, we tested the hypothesis that ascorbic acid (AA) reduces browning of fresh-cut apples (Red Delicious, RD, and Granny Smith, GS), and we investigated the impact of AA on phenylpropanoid metabolism of RD and GS. Apple slices were dipped in a solution of 100mg/L of chlorine dioxide

  5. Genome sequences of Ralstonia insidiosa type strain ATCC 49129 and strain FC1138, a strong biofilm producer isolated from a fresh-cut produce-processing plant

    Science.gov (United States)

    Ralstonia insidiosa FC1138 is a strong biofilm producer, isolated from a local fresh-cut produce processing plant. Here, we present the complete genome sequence of Ralstonia insidiosa FC1138 which includes two circular chromosomes and a plasmid. To our knowledge, this is the first reported complete ...

  6. Gram-negative bacterial isolates from fresh-cut processing plants enhance the presence of Escherichia Coli O157:H7 in dual-species biofilms

    Science.gov (United States)

    Biofilms formed by resident microflora may provide a microenvironment for foodborne bacterial pathogens to survive and cause cross-contamination in fresh-cut processing and handling facilities. The objective of this study is to determine the impact of individual bacteria strains isolated from two l...

  7. Survival and growth parameters of Escherichia coli 0157:H7, Salmonella Spp. and Listeria monocytogenes on cantaloupe fresh-cut pieces during storage

    Science.gov (United States)

    For health reasons, people are consuming fresh-cut fruits with or without minimal processing, thereby, exposing themselves to the risk of foodborne illness if such fruits are contaminated with bacteria pathogens. Cantaloupe rind surfaces were inoculated with a three cocktails of Escherichia coli O15...

  8. Effect of a bacteriophage cocktail in combination with modified atmosphere packaging in controlling Listeria monocytogenes on fresh-cut spinach

    Directory of Open Access Journals (Sweden)

    Boyacioglu O.

    2016-06-01

    Full Text Available A Listeria monocytogenes-specific bacteriophage cocktail was evaluated for its activity against a nalidixic acid-resistant L. monocytogenes (Lm-NalR isolate on fresh-cut spinach stored under modified atmosphere packaging at various temperatures. Pieces (~2 × 2 cm2 of fresh spinach inoculated with 4.5 log CFU/cm2 Lm-NalR were sprayed with the phage cocktail (6.5 log plaque-forming units [PFU]/cm2 or a control. The samples were stored at 4°C or 10°C for up to 14 d in sealed packages filled with either atmospheric air (AA or modified atmosphere (MA. At 4°C under AA, the phages significantly (P ≤ 0.05 lowered the Lm-NalR populations on spinach, compared to control-treated inoculated samples, by 1.12 and 1.51 log CFU/cm2 after 1 and 14 d, respectively. At 4°C under MA, Lm-NalR was significantly reduced by 1.95 log CFU/cm2 compared to control leaves after both 1 and 14 d. At 10°C under AA, the phages significantly reduced Lm-NalR by 1.50 and 2.51 log CFU/cm2 after 1 and 14 d compared to the control. Again at 10°C under MA, the phages significantly reduced Lm-NalR by 1.71 and 3.24 log CFU/cm2 compared to control after 1 and 14 d, respectively. The results support the potential of lytic bacteriophages in effectively reducing populations of L. monocytogenes on freshcut leafy produce, under both AA and MA conditions.

  9. Combination of sodium chlorite and calcium propionate reduces enzymatic browning and microbial population of fresh-cut "Granny Smith" apples.

    Science.gov (United States)

    Guan, Wenqiang; Fan, Xuetong

    2010-03-01

    Tissue browning and microbial growth are the main concerns associated with fresh-cut apples. In this study, effects of sodium chlorite (SC) and calcium propionate (CP), individually and combined, on quality and microbial population of apple slices were investigated. "Granny Smith" apple slices, dipped for 5 min in CP solutions at 0%, 0.5%, 1%, and 2% (w/v) either alone or in combination with 0.05% (w/v) SC, were stored at 3 and 10 degrees C for up to 14 d. Color, firmness, and microflora population were measured at 1, 7, and 14 d of storage. Results showed that CP alone had no significant effect on the browning of cut apples. Even though SC significantly inhibited tissue browning initially, the apple slices turned brown during storage at 10 degrees C. The combination of CP and SC was able to inhibit apple browning during storage. Samples treated with the combination of SC with CP did not show any detectable yeast and mold growth during the entire storage period at 3 degrees C. At 10 degrees C, yeast and mold count increased on apple slices during storage while CP reduced the increase. However, high concentrations of CP reduced the efficacy of SC in inactivating E. coli inoculated on apples. Overall, our results suggested that combination of SC with 0.5% and 1% CP could be used to inhibit tissue browning and maintain firmness while reducing microbial population. Practical Application: Apple slices, which contain antioxidants and other nutrient components, have emerged as popular snacks in food service establishments, school lunch programs, and for family consumption. However, the further growth of the industry is limited by product quality deterioration caused by tissue browning, short shelf-life due to microbial growth, and possible contamination with human pathogens during processing. Therefore, this study was conducted to develop treatments to reduce microbial population and tissue browning of "Granny Smith" apple slices. Results showed that an antimicrobial

  10. Processamento mínimo de tangerinas sob duas temperaturas Fresh-cut tangerine stored under two temperatures

    Directory of Open Access Journals (Sweden)

    Clarissa Damiani

    2008-02-01

    Full Text Available Conduziu-se este trabalho para avaliar o efeito de duas temperaturas na qualidade de Tangerina 'Poncã', minimamente processada, durante 12 dias. O processamento mínimo consistiu de lavagem, sanificação, retirada das cascas das frutas e embalagem. Os frutos foram refrigerados a 0ºC e 10ºC. Foram avaliados, a cada três dias, as seguintes variáveis: concentração de O2 e CO2, perda de massa, valor L*, a* e b*, pH, acidez titulável, sólidos solúveis, rendimento do suco, vitamina C e beta-caroteno. Concluiu-se que, as temperaturas de 0ºC e 10ºC, não tiveram influência distinta sobre a cor, teores de vitamina C e beta-caroteno e sólidos solúveis, contudo influenciaram o rendimento do suco, que foi melhor nas frutas armazenadas a 10ºC. A interação temperatura e tempo afetaram a perda de massa e o pH, observando-se que, quanto maior a temperatura e o tempo de armazenamento, maiores são as perdas sofridas pelos frutos minimamente processados.The objective of this work was to evaluate the effect of two temperatures on the quality of fresh-cut Tangerine 'Poncã' during 12 days. The minimal processing consisted of washing, sanitization, the peelling of the fruit and packing. The fruit were cooled at 0ºC and 10ºC. The following variable were evaluated every 3 days: concentration of O2 and CO2, mass loss, L *, a* and b * values, pH, titratable acidity, soluble solids, juiciness, vitamin C and beta-carotene. It was concluded that of temperature at 0ºC and 10ºC did not have different influence on color, vitamin C, beta-carotene and soluble solids, however held the juiciness what was the best in the fruit stored 10ºC. The interaction temperature and time affected the mass loss and pH, observing that the bigger temperature and the time of storage, the bigger are the losses suffered for the fresh-cut fruits.

  11. Effect of short-term air storage after removal from controlled-atmosphere storage on apple and fresh-cut apple quality.

    Science.gov (United States)

    Toivonen, Peter M A; Wiersma, Paul A; Hampson, Cheryl; Lannard, Brenda

    2010-03-15

    One of the realities of apple distribution for long-term stored fruit is that a controlled-atmosphere (CA) storage room will be unsealed and fruit held in air storage and marketed over several weeks. This work was conducted to determine the effect of post-CA air storage of whole fruit on potential shelf life for fresh-cut apple slices. Fresh-cut slices of 'Spartan' and 'Delicious' apples held in post-CA air storage for 2 or 4 weeks showed the least changes in cut surface color as compared with those made from apples immediately on removal from CA. Shelf life was most improved by post-CA air storage in the 'Spartan' apples, which were more advanced in maturity as compared with the 'Delicious' apples. Internal ethylene concentration, firmness, and respiration changed significantly with post-CA air storage, suggesting a relationship between physiological status of the whole fruit and shelf life of slices made from that fruit. The results support the hypothesis that apples had suppressed physiological activity in CA storage and are susceptible to accelerated deterioration upon cutting. Holding fruit for 2 weeks in air storage allowed recovery of physiological activity, which resulted in greater resistance to deterioration in response to fresh-cut processing.

  12. Do sun- versus shade-grown kiwifruits perform differently upon storage? An overview of fruit maturity and nutraceutical properties of whole and fresh-cut produce.

    Science.gov (United States)

    Landi, Marco; Tardelli, Francesca; Remorini, Damiano; Massai, Rossano; Guidi, Lucia

    2014-05-14

    Fresh-cut produce represents a good method to save about 25% of the kiwifruit not useful to meet the fresh fruit-marketing standard due to improper size and shape. For that reason, fresh-cut kiwifruit has been extensively studied. However, the comprehension of the influence of some aspects of cultivation might further increase the shelf life as well as the nutritional values of that fruit. This study explored the hypothesis that kiwifruits grown fully exposed to sunlight or partially shaded differently perform upon storage as whole fruit and as minimally processed produce. Flesh firmness (FF), total solids soluble (SSC), ascorbate (AAT), flavonoids (TFO), and phenols (TF) contents were evaluated in sliced and whole fruit upon 3 days of storage at 4 °C after 75 days of cold chamber storage at 0 °C. The activities of two enzymes related to the softening process, polygalacturonase (PG) and pectinmethylesterase (PME), were evaluated as well. FF and SSC were constitutively higher in sun-exposed fruit, and those characteristics remained higher during the storage as whole fruit. Greater constitutive content of AAT, TFO, and TP was found in sun-exposed whole fruit, although after cutting the reduction in their content was significantly lower in shaded fruits. PME and PG activities were higher only in whole shaded fruits, whereas no relevant differences occurred after cutting. In summary, sun-exposed fruits were more suitable for the fresh-fruit market, whereas the shaded counterpart displayed a good predisposition for use as fresh-cut produce, maintaining similar fruit maturity properties but higher nutraceutical values when sliced than fruit grown under full sun.

  13. Effect of postharvest ultraviolet-C treatment on the proteome changes in fresh cut mango (Mangifera indica L. cv. Chokanan).

    Science.gov (United States)

    George, Dominic Soloman; Razali, Zuliana; Santhirasegaram, Vicknesha; Somasundram, Chandran

    2016-06-01

    Postharvest treatments of fruits using techniques such as ultraviolet-C have been linked with maintenance of the fruit quality as well as shelf-life extension. However, the effects of this treatment on the quality of fruits on a proteomic level remain unclear. This study was conducted in order to understand the response of mango fruit to postharvest UV-C irradiation. Approximately 380 reproducible spots were detected following two-dimensional gel electrophoresis. Through gel analysis, 24 spots were observed to be differentially expressed in UV-C treated fruits and 20 were successfully identified via LCMS/MS. Postharvest UV-C treatment resulted in degradative effects on these identified proteins of which 40% were related to stress response, 45% to energy and metabolism and 15% to ripening and senescence. In addition, quality and shelf-life analysis of control and irradiated mangoes was evaluated. UV-C was found to be successful in retention of quality and extension of shelf-life up to 15 days. Furthermore, UV-C was also successful in increasing antioxidants (total flavonoid, reducing power and ABTS scavenging activity) in mangoes. This study provides an overview of the effects of UV-C treatment on the quality of mango on a proteomic level as well as the potential of this treatment in shelf-life extension of fresh-cut fruits. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  14. Quality changes of fresh-cut pomegranate arils during shelf life as affected by deficit irrigation and postharvest vapour treatments.

    Science.gov (United States)

    Peña-Estévez, María E; Gómez, Perla A; Artés, Francisco; Aguayo, Encarna; Martínez-Hernández, Ginés Benito; Otón, Mariano; Galindo, Alejandro; Artés-Hernández, Francisco

    2015-08-30

    The effect of two sustained deficit irrigation (SDI) strategies, compared to a control, on postharvest physicochemical, microbial, sensory quality attributes and anthocyanin content of fresh-cut pomegranates arils throughout 18 days at 5 °C was studied. Furthermore, the effect of vapour treatments (4, 7 and 10 s) compared to a conventional sanitizing treatment with NaClO on such quality parameters in combination with the preharvest treatments was also studied. According to sensory analyses, the shelf life of arils from control and SDI-irrigated fruit was established in 14 and 18 days at 5 °C, respectively, showing 4 and 7 s vapour treatment time the best sensory quality. No significant change was observed in physicochemical quality attributes, across all treatments during storage, while low microbial loads were registered (<3 log CFU g(-1)) after shelf life. Postharvest treatments that had least effect on anthocyanin content on processing day were 7 and 10 s. Vapour treatments of 7-10 s applied to pomegranate arils led to an extended shelf life up to 18 days at 5 °C with better results in SDI-irrigated samples with a water saving of 6-11%. © 2014 Society of Chemical Industry.

  15. Preliminary Investigations of the Anti-asthmatic Properties of the Aqueous Extract of Justicia pectoralis (Fresh Cut).

    Science.gov (United States)

    Cameron, C; Jacob, A S; Thomas, E A; Levy, A S

    2015-09-01

    Justicia pectoralis (fresh cut plant), family Acantheceae, is a herb that is native to central America and the Caribbean. A crude extract prepared from the leaves of Justicia pectoralis is commonly used in Jamaican ethnotraditional medicine to reduce difficulty in breathing and suppress wheezing in asthmatic individuals. To investigate the anti-inflammatory and antihistamine activity of an aqueous extract of Justicia pectoralis. In in vivo experiments, guinea pigs were sensitized by the method of Weinrich and Undem (1987). The effect of water on the wheals was assessed in the control group, n = 4. The effect of 3.3 mg of the crude extract was noted in histamine-induced wheals over a period of three hours. The extract was injected via intraperitoneal injections. In in vitro experiments, 3.3 mg of crude sample was tested for its effectiveness against histamine-induced tracheal contraction caused by cumulative dosing of histamine. The crude extract was efficacious in reducing the formation of histamine-induced wheals (p Justicia pectoralis reduced the formation of histamine-induced wheals in sensitized guinea pigs (p < 0.05) and also reduced histamine-induced tracheal smooth muscle contractions (p < 0.05). It blocked the effect of contraction produced by histamine in the airways; this property supports folklore claims for its use as an antihistamine.

  16. Effects of different storage temperature on fresh-cut lettuce during storage period%贮藏温度对鲜切莴笋品质的影响

    Institute of Scientific and Technical Information of China (English)

    杨霞; 舒晓斌; 吴广辉; 毕韬韬; 高愿军

    2011-01-01

    以莴笋为原料,研究贮藏温度(2,8,25℃)对鲜切莴笋贮藏期间失重率、呼吸强度、PPO活性、ΔE值、Vc含量、菌落总数和感官指标等理化指标的影响.结果表明,鲜切莴笋在2℃和8℃的低温下贮藏能有效降低失重率,抑制呼吸作用和Vc损失,降低PPO活性,减轻酶促褐变,控制微生物的生长和繁殖,贮藏12d后仍具有良好的感官指标,其中2℃下贮藏保鲜效果最好.%Fresh cut lettuces were used to study the effects of three different storage temperature (2,8 and 25 ℃) on physiology indexes such as weight lose? Respiration intensity* FPO activity, △E value, content of Vc, the total of bacteria and sensory indexes of fresh cut lettuce during storage period. The results showed that: it could inhibit the weight lose, respiration intensity, PPO activity, enzymatic browning, oxidization of Vc, growth and reproduction of microbial, when the fresh-cut lettuces were stored under a lower temperature (2 and 8℃). And they still had good sensory indexes after storing for 12 day. It had the best effect of fresh keeping, when the fresh-cut lettuces were stored under 2 ℃

  17. Investigation of Volatiles Emitted from Freshly Cut Onions (Allium cepa L. by Real Time Proton-Transfer Reaction-Mass Spectrometry (PTR-MS

    Directory of Open Access Journals (Sweden)

    Mette Marie Løkke

    2012-11-01

    Full Text Available Volatile organic compounds (VOCs in cut onions (Allium cepa L. were continuously measured by PTR-MS during the first 120 min after cutting. The headspace composition changed rapidly due to the very reactive volatile sulfurous compounds emitted from onion tissue after cell disruption. Mass spectral signals corresponding to propanethial S-oxide (the lachrymatory factor and breakdown products of this compound dominated 0–10 min after cutting. Subsequently, propanethiol and dipropyl disulfide predominantly appeared, together with traces of thiosulfinates. The concentrations of these compounds reached a maximum at 60 min after cutting. Propanethiol was present in highest concentrations and had an odor activity value 20 times higher than dipropyl disulfide. Thus, propanethiol is suggested to be the main source of the characteristic onion odor. Monitoring the rapid changes of VOCs in the headspace of cut onion necessitates a high time resolution, and PTR-MS is demonstrated to be a very suitable method for monitoring the headspace of freshly cut onions directly after cutting without extraction or pre-concentration.

  18. Effect of cassava starch coating on quality and shelf life of fresh-cut pineapple (Ananas comosus L. Merril cv "Pérola").

    Science.gov (United States)

    Bierhals, Vânia S; Chiumarelli, Marcela; Hubinger, Miriam D

    2011-01-01

    This research studied the influence of treatment with ascorbic acid, citric acid, and calcium lactate dipping and cassava starch edible coatings on quality parameters and shelf life of fresh-cut pineapple in slices during 12 d at 5 °C. After previous tests, the treatments selected for this study were samples dipped into antibrowning solution with 0.5% of ascorbic acid and 1% of citric acid, with and without 2% of calcium lactate and coated with 2% of cassava starch suspensions. Changes in weight loss, juice leakage, mechanical properties (stress at failure), color parameters (L* and H*), ascorbic acid content, sensory acceptance, and microbial growth of fruits were evaluated. Samples only treated with antibrowning agents were used as control. Edible coatings with and without calcium lactate were efficient in reducing weight loss, juice leakage, and maintaining firmness during storage. However, these samples showed more browning and the ascorbic acid content was reduced. All treatments presented good sensory acceptance (scores above 6). The determining factor of shelf life of pineapple slices was the microbial spoilage. A shelf life of 8 d was obtained for pineapple slices only treated with antibrowning agents. On the other hand, coated samples showed a reduced shelf life of 7 d and higher yeast and mold growth. Thus, although cassava starch coatings were efficient in reducing respiration rate, weight loss, and juice leakage and maintained mechanical properties, these treatments were not able to increase the shelf life of minimally processed pineapple. Practical Application: Pineapple fruit is highly appreciated for its aroma, flavor, and juiciness, but its immediate consumption is difficult. Therefore, pineapple is a potential fruit for minimal processing. However, shelf life of fresh-cut pineapple is very limited by changes in color, texture, appearance, off-flavors, and microbial growth. The use of edible coatings as gas and water vapor barrier and antibrowning

  19. Effects of rind removal on physicochemical quality characteristics of fresh-cut watermelon [Citrus lanatus (Thunb) Matsum & Nakai] during cold storage

    NARCIS (Netherlands)

    Petrou, P.; Soteriou, G.; Schouten, R.E.; Kyriacou, C.

    2013-01-01

    The impact of removing the rind from fresh-cut watermelon slices was assessed on the quality of the product during storage at 4 °C for 9 days. Flesh lycopene declined from 55.4 to 47.9 mg kg-1 f.w. and colour lightness (L*) increased from 43.2 to 45.8 after 2 days of storage. Initial heart and place

  20. Heat shock and UV-C abiotic stress treatments as alternative tools to promote fresh-cut carrot quality and shelf-life

    OpenAIRE

    Alegria, Carla Sofia Marques

    2015-01-01

    Doutoramento em Engenharia Alimentar - Instituto Superior de Agronomia Abiotic stress treatments, heat shock (HS_100 ºC/45 s) and UV-C (0.1-5 kJ.m-2), and two passive modified atmosphere packaging conditions were evaluated under the hurdle concept as alternative approaches to the standard processing of fresh-cut carrot (FCC). The significant phenolic accumulation, via phenylalanine-ammonia lyase activation, showed to be independent on key factors contributing to raw material bioactivity, c...

  1. Effectiveness of hydrothermal-calcium chloride treatment and chitosan on quality retention and microbial growth during storage of fresh-cut papaya.

    Science.gov (United States)

    Ayón-Reyna, Lidia E; Tamayo-Limón, Ransés; Cárdenas-Torres, Feliznando; López-López, Martha E; López-Angulo, Gabriela; López-Moreno, Héctor S; López-Cervántes, Jaime; López-Valenzuela, José A; Vega-García, Misael O

    2015-03-01

    Rapid degradation of fresh-cut papaya limits its marketability. Hydrothermal treatments in combination with a calcium dip, applied to whole fruit before slicing, and also the application of chitosan as a coating film, have been found to have very good results in maintaining the quality of fresh-cut fruits. Based on these considerations, the aim of this study was to evaluate the effect of hydrothermal treatment (HT; 49 °C, 25 min) containing calcium chloride (Ca; 1%, w/v) followed by dipping in chitosan (Chit; 1%, w/v, 3 min) on the physical, chemical, and microbial qualities of papaya slices stored at 5 °C for 10 d. Pulp color, firmness, ascorbic acid, total phenolics, β-carotene, and lycopene were evaluated every 2 d while the microbial quality (mesophilics, psychrophilics, molds, and yeasts) was evaluated every 5 d. Fruit treated with HT-Ca and HT-Ca + Chit showed better color and firmness retention than Control and Chit. Papaya slices treated with HT-Ca + Chit had higher nutritional content and lower microbial growth at the end of storage. The application of the HT-Ca + Chit could be used to reduce deterioration processes, maintaining physical, chemical, and microbial qualities and increasing the shelf life of fresh-cut papaya stored at 5 °C.

  2. Detection of postharvest changes of ascorbic acid in fresh-cut melon, kiwi, and pineapple, by using a low cost telemetric system.

    Science.gov (United States)

    Barberis, Antonio; Fadda, Angela; Schirra, Mario; Bazzu, Gianfranco; Serra, Pier Andrea

    2012-12-01

    The present paper deals with a novel telemetric device combined with a carbon amperometric sensor system to determine postharvest changes of ascorbic acid (AA) in fresh-cut fruits, without displacing products out of the storage rooms. The investigation was performed on kiwi, pineapple and melon, subjected to minimal processing, packaging, cold storage, and simulated shelf life. Results demonstrated that AA content of fresh-cut fruits of all species declines differently during storage. Cold storage notably reduced the degradation rate of AA in comparison with samples stored at 20°C. The cold-chain interruption resulted in a sharp AA content reduction when the optimal storage condition was not rapidly replaced. Unpredicted results showed a high activity of oxidative enzymes, which prevented AA detection in melon samples. Our sensor system allowed us to demonstrate that both ascorbate peroxidase and ascorbate oxidase affected the oxidative stability and the nutritional quality of fresh cut melon fruits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Effect of Gelatin-Based Edible Coatings Incorporated with Aloe vera and Black and Green Tea Extracts on the Shelf Life of Fresh-Cut Oranges

    Directory of Open Access Journals (Sweden)

    Mohsen Radi

    2017-01-01

    Full Text Available The aim of this study was to evaluate the effect of gelatin coating incorporated with Aloe vera gel (50,100% and green and black tea extracts (5,10% on physicochemical, microbial, and sensorial properties of fresh-cut oranges at 4°C for 17 days. Significant differences in terms of quality parameters were observed between the control and coated fresh-cut oranges. The highest variation of quality parameters was observed in control, while the least variations were observed in coated slices with 100% Aloe vera and 10% green tea extract. The weight loss was increased with time, but the coating treatment especially with 100% Aloe vera had significant effect on the prevention of weight loss. Also, Aloe vera coated samples obtained the highest score in sensory evaluation. Coating with gelatin incorporated with Aloe vera and green tea extracts successfully retarded the microbial growth and therefore extended the shelf life of fresh-cut oranges during cold storage.

  4. 405 ± 5 nm light emitting diode illumination causes photodynamic inactivation of Salmonella spp. on fresh-cut papaya without deterioration.

    Science.gov (United States)

    Kim, Min-Jeong; Bang, Woo Suk; Yuk, Hyun-Gyun

    2017-04-01

    This study evaluated the antibacterial effect of 405 ± 5 nm light emitting diode (LED) illumination against four Salmonella serovars on fresh-cut papaya and on fruit quality at various storage temperatures. To determine the antibacterial mechanism of LED illumination at 0.9 kJ/cm(2), oxidative damage to DNA and membrane lipids of Salmonella in phosphate-buffered saline solution was measured. The populations of Salmonella on cut fruits were significantly (P fruits. Levels of bacterial DNA oxidation significantly increased, whereas lipid peroxidation in bacterial membrane was not observed, suggesting that DNA oxidation contributes to photodynamic inactivation by LED illumination. LED illumination did not adversely affect the physicochemical and nutritional qualities of cut papaya, regardless of storage temperature. These results indicate that a food chiller equipped with 405 ± 5 nm LEDs can preserve fresh-cut papayas in retail stores without deterioration, minimizing the risk of salmonellosis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Effects of Different Packaging Materials on Fresh-keeping of Fresh-cut Potatoes%不同包装材料对鲜切马铃薯的保鲜效果

    Institute of Scientific and Technical Information of China (English)

    覃海元; 杨昌鹏; 潘嫣丽; 黄卫萍; 陈智理

    2009-01-01

    [目的] 研究不同包装材料对鲜切马铃薯的保鲜效果.[方法] 马铃薯经挑选、去皮后切成1.5~2.0 cm厚的切片,用浓度1%的柠檬酸溶液浸泡护色3 min后,放入塑料托盘中,分别用PE、PVDC和PP/PE保鲜膜或复合袋包装,放入5 ℃的冰柜里冷藏8 d,当天及其后每2 d检测1次样品.[结果] 透气性差的PP/PE包装较其他材料更有利于延缓鲜切马铃薯中还原型抗坏血酸的减少,抑制褐变,同时延缓组织内丙二醛(MDA)的积累和电解质渗出率的增加,从而延缓其衰老.[结论] 不同包装材料对鲜切马铃薯的保鲜效果有影响.%[Objective]The research aimed to study the fresh-keeping effects of different kinds of packaging materials on fresh-cut potatoes. [Method]Potato were chosen, peeled and cut into pieces (1.5-2.0 cm). After being dipped in 1.0 % citric acid solution for 3 min, the potato pieces were placed in plastic trays, covered with PE, PVDC and PE/PP film respectively, and then stored at 5 ℃ for 8 days. The fresh-cut potatoes were measured at 0, 2, 4, 6 and 8 day respectively. [Result]The results showed that PE/PP packaging with low gas-permeability could retain ascorbic acid, inhibit browning, slow down the accumulation of malondialdehyde (MDA) and electrolyte leakage, so as to slow down senescing. [Conclusion]Different kinds of packaging materials had different fresh-keeping effects on fresh-cut potatoes.

  6. Effect of Hydrogen Peroxide in Combination with Minimal Thermal Treatment for Reducing Bacterial Populations on Cantaloupe Rind Surfaces and Transfer to Fresh-Cut Pieces.

    Science.gov (United States)

    Ukuku, Dike O; Mukhopadhyay, Sudarsan; Geveke, David; Olanya, Modesto; Niemira, Brendan

    2016-08-01

    Surface structure and biochemical characteristics of bacteria and produce play a major role in how and where bacteria attach, complicating decontamination treatments. Whole cantaloupe rind surfaces were inoculated with Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes at 10(7) CFU/ml. Average population size of Salmonella, Escherichia coli O157:H7, and L. monocytogenes recovered after surface inoculation was 4.8 ± 0.12, 5.1 ± 0.14, and 3.6 ± 0.13 log CFU/cm(2), respectively. Inoculated melons were stored at 5 and 22°C for 7 days before washing treatment interventions. Intervention treatments used were (i) water (H2O) at 22°C, (ii) H2O at 80°C, (iii) 3% hydrogen peroxide (H2O2) at 22°C, and (iv) a combination of 3% H2O2 and H2O at 80°C for 300 s. The strength of pathogen attachment (SR value) at days 0, 3, and 7 of storage was determined, and then the efficacy of the intervention treatments to detach, kill, and reduce transfer of bacteria to fresh-cut pieces during fresh-cut preparation was investigated. Populations of E. coli O157:H7 attached to the rind surface at significantly higher levels (P < 0.05) than Salmonella and L. monocytogenes, but Salmonella exhibited the strongest attachment (SR value) at all days tested. Washing with 3% H2O2 alone led to significant reduction (P < 0.05) of bacteria and caused some changes in bacterial cell morphology. A combination treatment with H2O and 3% H2O2 at 8°C led to an average 4-log reduction of bacterial pathogens, and no bacterial pathogens were detected in fresh-cut pieces prepared from this combination treatment, including enriched fresh-cut samples. The results of this study indicate that the microbial safety of fresh-cut pieces from treated cantaloupes was improved at day 6 of storage at 5°C and day 3 of storage at 10°C.

  7. Research advances in biological preservatives of fresh-cut fruits and vegetables%鲜切果蔬中生物保鲜剂的研究进展

    Institute of Scientific and Technical Information of China (English)

    董妍; 胡文忠; 姜爱丽

    2015-01-01

    随着人们对食品质量与安全的要求日益提高,鲜切果蔬保鲜技术迅速发展,生物保鲜剂因具有安全、高效等特点成为鲜切果蔬保鲜的研究热点。鲜切果蔬经分级、清洗、修整、去皮、切分、保鲜、包装等过程处理后,机械损伤、生理代谢、病原微生物污染等问题会引起鲜切果蔬腐烂、品质下降,给鲜活农产品的经济贸易带来了巨大损失,并对人类生命安全造成了重大威胁,因此本文综述了温度、气体环境、生理生化反应、微生物等几项能够导致鲜切果蔬褐变腐烂、品质下降的重要影响因素;总结了3种生物保鲜剂在鲜切果蔬保鲜中的应用,包括植物类天然保鲜剂、动物类天然保鲜剂和微生物保鲜剂;讨论了生物保鲜剂的不足,并对今后生物保鲜剂的发展进行了展望。%As the requirements of food quality and safety increasing, the preservation technology of fresh-cut fruits and vegetables are developed rapidly. Biological preservatives with safe, efficient and other characteristics becomes the hotspot of fresh-cut fruits and vegetables. Fresh-cut fruits and vegetables are processed with cleaning, trimming, peeling, cutting, and so on. In this process, mechanical damage, physiological metabolism, pathogen infection and other problems can cause decay and quality decline of fresh-cut fruits and vegetables. This has brought a huge loss to the economy and trade of fresh agricultural products, and this is also harmful for human health. This paper reviewed several important factors such as temperature, gas environment, physiological and biochemical reactions, microbial, which could cause browning, decay and poor quality of fresh-cut fruits and vegetables, and the application of biological preservatives on fresh-cut fruits and vegetables, including botanical natural preservatives, animal natural preservatives and microbial natural preservatives. Finally this paper

  8. 乐平雪梨瓜鲜切保鲜技术研究%Research on Preservation of Fresh-cut Le-ping Melon

    Institute of Scientific and Technical Information of China (English)

    曾荣; 潘炎霞; 林丽超

    2015-01-01

    With fresh-cut Le-ping melon as test materials ,using different blanching temperature and time processing of fresh-cut Le-ping melon,as determined by sensory evaluation,vitamin C content and other indicators,thus obtained the optimum blanching temperature and time combination.On this basis,the combination of the food grade chitosan(1.0%,1.5%)for coating film,got the best fresh method.The results showed that the optimum combination was blanching 60℃2 min,the best combination of blanching+1.5%chitosan worked best.The process could significantly reduce the decline rate of the quality of fresh-cut melon and effectively extend the shelf life.%以鲜切乐平雪梨瓜为试验材料,采用不同的热烫温度和时间处理鲜切雪梨瓜,通过感官评定、VC含量等指标测定,从而得出最佳热烫温度与时间的组合。在此基础上,结合使用食品级的壳聚糖(1.0%、1.5%)进行涂膜处理,得到最佳保鲜方法。结果表明:最佳的处理为60℃热烫2min,同时结合1.5%壳聚糖涂膜保鲜效果最好。通过处理,明显降低了鲜切雪梨瓜品质的下降速度,有效延长了货架期。

  9. Fresh cut cassava subjected to gamma radiationMandioca minimamente processada submetida a radiação gama

    Directory of Open Access Journals (Sweden)

    Mariana Gonçalves Lozano

    2012-04-01

    Full Text Available Fresh cut cassava is an alternative to prolong roots commercialization period, adding value to the raw material and assisting the consumer’s needs that seeks for products of easy preparation. The aim of this work was to evaluate the quality of fresh cut cassava subjected to gamma radiation. For processing cassava roots (IAC – 567-70 were used, after preparation were packed in expanded polystyrene (EPS trays, covered by low density polyethylene (LDPE plastic film, being subjected to gamma radiation in the doses 0 (control, 0.5; 1.0; 1.5; 2.0 KGy. Another treatment was also carried out in which roots were vacuum packed in nylon + polyethylene. Packed roots of all treatments were stored under refrigeration (5 ± 1 ºC and evaluations were made after 0, 3, 6, 9 and 12 days. Evaluated analyses were: titrable acidity, pH, firmness, coloration, polyphenoloxidase activity, cooking time and roots hydration percentage. Evaluations just proceeded until the nine storage day, because after this period the roots already presented visually detectable physiologic and microbiological alterations. For titrable acidity, the vacuum packed roots had the lowest values, followed by the control packed in trays. For the other treatments, values of acidity increased and influenced the pH values. For the other appraised parameters there was no significant difference among treatments, but alterations were observed with the storage. The firmness decreased with the storage. Brightness values and yellow color component decreased with the storage and the b * (green color values increased. Polyphenoloxidase activity was maximum in the day of elaboration of the product and it decreased with the storage. Cooking time and roots hydration percentage decreased with the roots storage.A mandioca minimamente processada é uma alternativa para prolongar o período de comercialização das raízes, agregando de valor a matéria prima e atendendo as necessidades do consumidor que

  10. Effects of postharvest application of 1-MCP and postcutting dip treatment on the quality and nutritional properties of fresh-cut kiwifruit.

    Science.gov (United States)

    Antunes, Maria D C; Dandlen, Susana; Cavaco, Ana M; Miguel, Graça

    2010-05-26

    Consumption of minimally processed fruit and vegetables has increased significantly in the past few years due to the consumers' life style. The aim of this study was to evaluate the effect of treatment with ascorbic acid or calcium chloride on the quality parameters of fresh-cut kiwifruit prepared from fruit previously stored for 3 months, either treated or not treated with 1-methylcyclopropene (1-MCP) before storage. Harvested fruit were treated with 1 microL L(-1) 1-MCP for 20 h at room temperature ( approximately 20 degrees C) (MCP) or had no treatment (C) and were then stored at 0 degrees C. After 3 months, fruit were removed from storage, peeled, and cut longitudinally in quarters, dipped in 2% ascorbic acid (Asc), 2% calcium chloride (Ca), or just water (cont), and kept at 2 degrees C for 8 days. Measurements of firmness, soluble solids content (SSC) ( degrees Brix), color (CIE L*, a*, b*), electrolyte leakage, sugars, organic acids, total phenolics, and antioxidant activity (DPPH and ABTS) were performed at 0, 4, and 8 days. A taste panel was performed on the seventh shelf life day. It was shown that whole MCP-treated kiwifruit kept better than the control through the 3 months storage, this effect being lost through the fresh-cut shelf life period. Furthermore, the postcut dip on 2% CaCl(2) was effective on delaying softening and browning of fresh-cut kiwifruit, which were also the fruit preferred by panelists. Both ascorbic acid and CaCl(2) were effective on preserving or improving nutritional properties (phenolics, ascorbic acid, DPPH, and ABTS) mainly in the first 4 days of shelf life. The CaCl(2) had a further beneficial effect until 8 shelf life days. It is suggested that CaCl(2) is better in keeping overall quality through 8 days of shelf life at 2 degrees C in fresh-cut kiwifruit followed by Asc, and 1-MCP has negligible effect in the conditions of this experiment.

  11. Effect of Ozone and Calcium Lactate Treaments on Browning and Textured Properties of Fresh-Cut Lettuce.

    OpenAIRE

    Rico, Daniel; Martin-Diana, Ana Belen; Henehan, Gary; Frias, Jesus Maria; Barat, J.; Barry-Ryan, Catherine

    2007-01-01

    The preservation of quality of fresh products is relevant for the industry due to its economic impact. This paper presents a comprehensive review of the use of different sources of calcium to preserve fresh fruits and vegetables in order to extend the shelf life and enhance the nutritional value. Emphasis is on discussing about the best sources of calcium, concentration, temperature and method of application, suitability of the commodities; and some hints for the cost/benefit analysis are pre...

  12. Modeling transfer of Escherichia coli O157:H7 and Listeria monocytogenes during preparation of fresh-cut salads: impact of cutting and shredding practices.

    Science.gov (United States)

    Zilelidou, Evangelia A; Tsourou, Virginia; Poimenidou, Sofia; Loukou, Anneza; Skandamis, Panagiotis N

    2015-02-01

    Cutting and shredding of leafy vegetables increases the risk of cross contamination in household settings. The distribution of Escherichia coli O157:H7 and Listeria monocytogenes transfer rates (Tr) between cutting knives and lettuce leaves was investigated and a semi-mechanistic model describing the bacterial transfer during consecutive cuts of leafy vegetables was developed. For both pathogens the distribution of log10Trs from lettuce to knife was towards low values. Conversely log10Trs from knife to lettuce ranged from -2.1 to -0.1 for E. coli O157:H7 and -2.0 to 0 for L. monocytogenes, and indicated a more variable phenomenon. Regarding consecutive cuts, a rapid initial transfer was followed by an asymptotic tail at low populations moving to lettuce or residing on knife. E. coli O157:H7 was transferred at slower rates than L. monocytogenes. These trends were sufficiently described by the transfer-model, with RMSE values of 0.426-0.613 and 0.531-0.908 for L. monocytogenes and E. coli O157:H7, respectively. The model showed good performance in validation trials but underestimated bacterial transfer during extrapolation experiments. The results of the study can provide information regarding cross contamination events in a common household. The constructed model could be a useful tool for the risk-assessment during preparation of leafy-green salads.

  13. Modificações sensoriais em cenoura minimamente processada e armazenada sob refrigeração Sensory modifications of fresh cut carrots stored under refrigeration

    Directory of Open Access Journals (Sweden)

    Josane Maria Resende

    2004-03-01

    Full Text Available Foram avaliadas as modificações sensoriais em cenoura minimamente processada em dois tipos de cortes durante o armazenamento sob refrigeração. Semanalmente avaliou-se a aparência, a cor, o aroma, o sabor e a textura de cenouras cv. Nantes, minimamente processadas, acondicionadas em potes de polietileno tereftalato (PET e armazenadas a 7ºC, por 14 dias. Para definir a freqüência de consumo e preferência pelo tipo de corte, amostras do produto foram apresentadas ao público e os resultados foram anotados em porcentagem em relação ao número total de pessoas consultadas. Com o decorrer do armazenamento houve redução nos escores para a aparência e a cor, enquanto que o sabor e a textura melhoraram em ambos os cortes. Cenouras raladas apresentaram melhor cor e aparência em relação à cenoura cortada em rodelas, entretanto o sabor e a textura foram melhores para cenouras em rodelas. As cenouras raladas são as mais indicadas para o consumo uma vez que a aparência é o atributo que mais causa impacto na escolha pelo consumidor e dentro desta a cor é a característica mais relevante. A freqüência de consumo deste tipo de produto esta aumentando gradativamente e em relação à preferência pelo tipo de corte, o consumidor optou pela cenoura ralada pela sua maior praticidade e versatilidade de uso.Sensory modifications were evaluated in carrots cv Nantes lightly processed in two kinds of cut (grated and sliced during the storage under refrigeration. Fresh cut carrots were packed in polyethylene tereftalato (PET boxes and stored at 7ºC for 14 days. The carrot's appearance, color, aroma, flavor and texture were evaluated weekly. To obtain the frequency of consumption and preference of kind of cut, samples were offered to people to try. During the storage of both kinds of cut, a reduction in scores for appearance and color occurred, while flavor and texture scores were improved. Fresh cut carrots in the grated form presented better

  14. Study on the Controlling Process of Freezing Point in Fresh-cut Litchi Pulp%鲜切荔枝果肉冰点调节工艺

    Institute of Scientific and Technical Information of China (English)

    吴汶飞; 余小林; 胡卓炎; 周宇

    2011-01-01

    Effects of different freezing point regulators including sucrose, sorbitol and glucose on the freezing point of fresh - cut litchi pulp were evaluated and optimized by response surface methodology. Results showed that the optimal conditions were: sorbitol content 6.24% , glucose content 7.31% and sucrose content 40.93%. Under the optimal conditions, the freezing point of the fresh -cut litchi pulp decreased to -4.15℃ , close to the predicted val ue of -4.13℃. The optimal freezing point of the fresh - cut litchi pulp was reduced by 1.3℃ comparing to the control group.%研究了蔗糖、山梨醇、葡萄糖3种冰点调节剂对降低鲜切荔枝果肉冰点的效果及复配浓度的影响。在单因素实验的基础上,以鲜切荔枝果肉的冰点为响应值,通过响应曲面法建立回归模型,得到山梨醇、葡萄糖、蔗糖3种冰点调节剂的优化复配浓度为:山梨醇6.24%,葡萄糖7.31%,蔗糖40.93%。鲜切荔枝果肉经此优化复配浓度在3cc、浸渍3h处理后,其冰点可降至-4.15℃,与模型预测值(-4.13℃)接近,比未处理果肉的冰点降低了1.3℃。

  15. Survival and growth of Cronobacter sakazakii on fresh-cut fruit and the effect of UV-C illumination and electrolyzed water in the reduction of its population.

    Science.gov (United States)

    Santo, David; Graça, Ana; Nunes, Carla; Quintas, Célia

    2016-08-16

    Cronobacter sakazakii, found in foods such as powdered infant formula and plant origin ready-to-eat food, is an opportunistic pathogen to infants, neonates and vulnerable adults. The objective of this study was to monitor the growth of C. sakazakii in fresh-cut 'Royal gala' apple, 'Rocha' pear, and 'Piel de sapo' melon, and the effect of UV-C illumination, acidic electrolyzed water (AEW) and neutral electrolyzed water (NEW) in the reduction of its population. Fresh-cut fruits were inoculated and incubated at different temperatures during 10days while monitoring C. sakazakii. The inhibitory activity of different doses of UV-C (0-10kJ.m(2)), electrolyzed water and sodium hypochlorite (SH) (100ppm chlorine) was evaluated on the fruits inoculated with C. sakazakii. The bacterium showed a significant growth in the fruits at 12 and 20°C, but did not grow at 4°C, despite having survived for 10days. At 8°C, adaptation phases of 0.6-3.9days were estimated in the fruits before exponential growth. The UV-C 7.5 and 10kJ/m(2) produced greater C. sakazakii population decreases (2-2.4logcfu/g) than AEW (1.3-1.8logcfu/g), NEW (1-1.2logcfu/g) and SH (0.8-1.4logcfu/g). The UV-C decontamination system and refrigeration at 4°C, may contribute to the product's safety and quality. The results help better understand the behavior of C. sakazakii on fresh-cut fruit alerting producers of the necessity to respect the high hygienic practices, adequate refrigerating temperature maintenance and caution with the tendency to prolong the validity of this kind of ready-to-eat food. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Effects of ultraviolet light (UV-C) and heat treatment on the quality of fresh-cut Chokanan mango and Josephine pineapple.

    Science.gov (United States)

    George, Dominic Soloman; Razali, Zuliana; Santhirasegaram, Vicknesha; Somasundram, Chandran

    2015-02-01

    The effects of ultraviolet (UV-C) and medium heat (70 °C) treatments on the quality of fresh-cut Chokanan mango and Josephine pineapple were investigated. Quality attributes included physicochemical properties (pH, titratable acidity, and total soluble solids), ascorbic acid content (vitamin C), antioxidant activity, as well as microbial inactivation. Consumers' acceptance was also investigated through sensory evaluation of the attributes (appearance, texture, aroma and taste). Furthermore, shelf-life study of samples stored at 4 ± 1 °C was conducted for 15 d. The fresh-cut fruits were exposed to UV-C for 0, 15, 30, and 60 min while heat treatments were carried out at 70 °C for 0, 5, 10 and 20 min. Both UV-C and medium heat treatments resulted in no significant changes to the physicochemical attributes of both fruits. The ascorbic acid content of UV-C treated fruits was unaffected; however, medium heat treatment resulted in deterioration of ascorbic acids in both fruits. The antioxidants were enhanced with UV-C treatment which could prove invaluable to consumers. Heat treatments on the other hand resulted in decreased antioxidant activities. Microbial count in both fruits was significantly reduced by both treatments. The shelf life of the fresh-cut fruits were also successfully extended to a maximum of 15 d following treatments. As for consumers' acceptance, UV-C treated fruits were the most accepted as compared to their heat-treated counterparts. The results obtained through this study support the use of UV-C treatment for better retention of quality, effective microbial inactivation and enhancement of health promoting compounds for the benefit of consumers.

  17. Efeito do tipo de corte e sanificantes no amaciamento de pequi (Caryocar brasiliense Camb. minimamente processado Effect of the cut type and sanitizers on the softening of fresh cut pequi fruit (Caryocar brasiliense Camb.

    Directory of Open Access Journals (Sweden)

    Luiz José Rodrigues

    2007-12-01

    Full Text Available Frutos e hortaliças minimamente processados devem apresentar atributos de conveniência e qualidade do produto fresco. Com o presente trabalho, objetivou-se avaliar a influência dos sanificantes hipoclorito de sódio (NaClO 50 ppm e 100 ppm e peróxido de hidrogênio (H2O2 4% e 6%, sobre os processos envolvidos no amaciamento de pequi (Caryocar brasiliense Camb. minimamente processado submetido a dois tipos de processamento: "caroço fatiado" e "caroço inteiro" e armazenado a 6 ± 1ºC e 90% a 95% UR, durante 15 dias. A cada três dias foram avaliados: perda de massa, firmeza, pectina total, pectina solúvel, atividade de pectinametilesterase (PME e atividade de poligalacturonase (PG. O pequi minimamente processado apresentou perda de massa e decréscimo de firmeza ao longo do período de armazenamento, concomitante ao aumento da atividade da enzima poligalacturonase, bem como solubilização de substâncias pécticas. Não foi verificada atividade de PME no pequi minimamente processado avaliado. Os caroços fatiados apresentaram maior teor de pectina solúvel, do 3° ao 6° dia e atividade da enzima poligalacturonase, do 3° ao 12° dia de armazenamento, em relação aos caroços inteiros. A sanificação com NaClO 50 ppm e 100 ppm, H2O2 4% e 6% determinou maior solubilização péctica em pequis minimamente processados, ao longo do armazenamento, não sendo observada influência dos sanificantes sobre as variáveis firmeza, perda de massa e atividade de poligalacturonase.Fresh cut fruits and vegetables should present convenience and quality features of the fresh produce. The present work aimed to evaluate the influence of the sanitizers 50ppm and 100ppm sodium hypochloride (NaClO and 4% and 6% hydrogen peroxide (H2O2 on the involved processes in the softening of fresh cut pequi fruit (Caryocar brasiliense Camb. submitted to two types of processing: "sliced stone" and "whole stone" stored at 6 ± 1°C and 90% to 95% of RH during 15 days

  18. Quality of fresh retail pork cuts stored in modified atmosphere under temperature conditions simulating export to distant markets.

    Science.gov (United States)

    McMullen, L M; Stiles, M E

    1994-01-01

    The effect of storage temperature on microbial and sensory quality of retail cuts of pork was determined on samples stored under temperature regimens designed to simulate conditions that could be encountered in accessing distant markets with retail-ready product. Samples were packaged in modified atmosphere with 100% CO(2) and export of retail-ready pork cuts to distant markets with a three-week time for delivery to market at -1·5°C can be achieved with one to two weeks of marketing time at retail market at 4 to 7°C.

  19. Effect of chitosan molecular weight on the functional properties of chitosan-maltose Maillard reaction products and their application to fresh-cut Typha latifolia L.

    Science.gov (United States)

    Li, Song-Lin; Lin, Jing; Chen, Xiao-Ming

    2014-02-15

    The objective was to evaluate antimicrobial, antioxidant and copper-chelating activities of Maillard reaction products (MRP) prepared from maltose and different molecular weight chitosan, and their effects on preservation of fresh-cut Typha latifolia L. (TLL). LMRP (maltose and low molecular weight chitosan MRP) showed the highest browning and UV absorbance as well as fluorescence intensity. The DPPH radical scavenging activity, reducing power and copper-chelating activity of chitosan-maltose MRP varied depending on the chitosan molecular weight. HMRP (maltose-high molecular weight chitosan MRP) exhibited better effects on inhibiting PPO activity and discoloration, alleviating declines of total soluble solids and ascorbic acid content of fresh-cut TLL. LMRP and MMRP (maltose-medium molecular weight chitosan MRP) effectively decreased weight loss and maintained firmness of TLL, respectively. These results indicated that molecular weight of chitosan had a great impact on the functional properties of chitosan-maltose MRP and their application to be used as a preservative. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. A comparative study on the effectiveness of ozonated water and peracetic acid in the storability of packaged fresh-cut melon.

    Science.gov (United States)

    Botondi, Rinaldo; Moscetti, Roberto; Massantini, Riccardo

    2016-05-01

    Ozonated water and peracetic acid were tested as sanitizers to enhance the storability of fresh-cut melon cubes. Sanitizers were also combined with suitable packaging materials (polypropylene and polylactic acid based plastic films). Fresh-cut melon cubes were stored at 4 °C for up to 7 days. Ozonated water and peracetic acid treatments were given by dipping cubes into 0.8 ppm O3 and 100 ppm Tsunami 100™ solutions, respectively, for 3 min. Both sanitizers exhibited efficiency in reducing the total microbial counts on melon cubes (peracetic acid treatment in combination with polypropylene film packaging, consequently developing off-odors starting from day 3. Strong color changes were noted in cubes stored in polylactic acid packaging after 7 days of storage, affecting the sensory quality of the melon cubes. Sensory evaluation (overall visual quality) indicated loss in flavor in the polypropylene packaging. The overall visual quality started to decline on 3rd day because of the development of translucency.Overall, the use of ozone in combination with polypropylene packaging provided the best solution to maintain the quality of melon cubes for up to 5 days of storage at 4 °C.

  1. Interactions between sanitizers and packaging gas compositions and their effects on the safety and quality of fresh-cut onions (Allium cepa L.).

    Science.gov (United States)

    Page, Natalie; González-Buesa, Jaime; Ryser, Elliot T; Harte, Janice; Almenar, Eva

    2016-02-01

    Onions are one of the most widely utilized vegetables worldwide, with demand for fresh-cut onions steadily increasing. Due to heightened safety concerns and consumer demand, the implications of sanitizing and packaging on fresh-cut onion safety and quality need to be better understood. The objective of this study was to investigate the effect of produce sanitizers, in-package atmospheres, and their interactions on the growth of Salmonella Typhimurium, mesophilic aerobic bacteria, yeast and mold, and the physico-chemical quality of diced onions to determine the best sanitizer and in-package atmosphere combination for both safety and quality. Diced onions were inoculated or not with S. Typhimurium, sanitized in sodium hypochlorite, peroxyacetic acid, or liquid chlorine dioxide, and then packaged in either polylactic acid bags containing superatmospheric O2, elevated CO2/reduced O2, or air, or in polyethylene terephthalate snap-fit containers. Throughout 14 days of storage at 7 °C, packaged diced onions were assessed for their safety (S. Typhimurium), and quality (mesophilic aerobic bacteria, yeasts and molds, physico-chemical analyses, and descriptive and consumer acceptance sensory panels). While sanitizer affected (Ppackage atmosphere had a significant (Ppackage atmosphere combination for enhancing the safety and quality of packaged diced onions. In addition, this combination led to diced onions acceptable for purchase after 2 weeks of storage by trained and consumer panels.

  2. Enzymatic Browning Controling of Fresh Cut-lotus Roots%鲜切莲藕酶促褐变控制的研究

    Institute of Scientific and Technical Information of China (English)

    郝亚勤

    2014-01-01

    选择柠檬酸(CA)、D-异抗坏血酸钠(D-EA)、乙二胺四乙酸二钠(EDTA-2Na)3种对莲藕(Neulmbo nucifera Gaerth)多酚氧化酶(Polyphenol oxidase,PPO)活性抑制率较高的抑制剂,作为鲜切莲藕酶促褐变抑制剂,研究3种抑制剂及其组合对抑制鲜切莲藕酶促褐变的效应。结果表明,3种褐变抑制剂最佳组合用量为2.5 g / L CA+1.5 g / L D-EA+1.5 g / L EDTA-2Na。%The high inhibitors including Citric acid (CA), Sodium D-isoascorbate (D-EA) and Edathamil disodium (EDTA-2Na) of activity of polyphenol oxidase of lotus root Neulmbo nucifera Gaerth were used as the enzymatic browning inhibitors of fresh-cut lotus roots. The effects of the inhibitors and its combination on the inhibition of enzymatic browning of fresh cut lotus root were studied. The results showed that the optimal dosage of combination of this three enzymatic browning inhibitors was 2. 5g/LCA+1. 5g/LD-EA+1. 5g/LEDTA-2Na.

  3. Hydrogen sulfide prolongs postharvest storage of fresh-cut pears (Pyrus pyrifolia by alleviation of oxidative damage and inhibition of fungal growth.

    Directory of Open Access Journals (Sweden)

    Kang-Di Hu

    Full Text Available Hydrogen sulfide (H2S has proved to be a multifunctional signaling molecule in plants and animals. Here, we investigated the role of H2S in the decay of fresh-cut pears (Pyrus pyrifolia. H2S gas released by sodium hydrosulfide (NaHS prolonged the shelf life of fresh-cut pear slices in a dose-dependent manner. Moreover, H2S maintained higher levels of reducing sugar and soluble protein in pear slices. H2S significantly reduced the accumulation of hydrogen peroxide (H2O2, superoxide radicals (•O2(- and malondialdehyde (MDA. Further investigation showed that H2S fumigation up-regulated the activities of antioxidant enzymes ascorbate peroxidase (APX, catalase (CAT, and guaiacol peroxidase (POD, while it down-regulated those of lipoxygenase (LOX, phenylalanine ammonia lyase (PAL and polyphenol oxidase (PPO. Furthermore, H2S fumigation effectively inhibited the growth of two fungal pathogens of pear, Aspergillus niger and Penicillium expansum, suggesting that H2S can be developed as an effective fungicide for postharvest storage. The present study implies that H2S is involved in prolonging postharvest storage of pears by acting as an antioxidant and fungicide.

  4. The Effect of Isabgol (Plantago psyllium Mucilage and Shiraz Thyme Essential Oils on Microbial Load and Improving Shelf Life of Fresh-Cut Carrot

    Directory of Open Access Journals (Sweden)

    M. Azizi

    2016-02-01

    Full Text Available Introduction: Fresh-cut produce graduated to retail during the1990s, especially for lettuce, cabbage, carrots and other similar vegetables. The high microbial loads of these products after harvest can be substantially reduced through a cleaning in flowing chlorinated water and adistribution under ensured controlledrefrigeration. Therefore, a good number of convenient ready-to-use greens were launched to the market in the past decade. Nowadays, theuse of this technology to achieve similar results in fruit products is one of the most challengingtargets for processors. However, there is anumber of issues that still need to beovercomebeforefresh-cut fruit commodities can be sparked off to anoutstanding position in the segment of lightly-treatedrefrigerated foods. The importance of freshly cut products increases day by day. Tissue and cell rupture leads to a decrease in the shelf life of these products. On the other hand, these products due to increased enzyme activity, respiration rate and microbiological considerations that affect the health of these productsrequires highly attention.To increase the shelf life of the products and prevent undesirable changes in cut slices of fruit or vegetables a coating on the surface of these products has been suggested. Mucilages and essential oils of herbs are natural compounds that can be used to create such covers. The advantages of these coatings are their bactericidal effect, maintenanceof pleasant taste and other physical and chemical characteristics of the product and even decrease of environmental pollution. In this research, the effect of natural compounds such as Zataria multiflora essential oil (EO and Plantagopsyllium mucilage on storage life and microbial load of fresh cut carrot was studied. Materials and Methods: The research was conducted in two separate experiments on fresh-cut carrot: In the first experiment, the effect of different concentrations of Plantago psyllium mucilage (0,100, 200, and

  5. Use of UV-C treatments to maintain quality and extend the shelf life of green fresh-cut bell pepper (Capsicum annuum L.).

    Science.gov (United States)

    Rodoni, Luis M; Concellón, Analía; Chaves, Alicia R; Vicente, Ariel R

    2012-06-01

    The objective of this work was to select a Ultraviolet-C (UV-C) treatment for fresh-cut mature green bell pepper, and to evaluate the effect of its combination with refrigeration on quality maintenance. Bell pepper sticks were treated with 0, 3, 10, or 20 kJ/m² UV-C in the outer (O), inner (I), or both sides of the pericarp (I/O) and stored for 8 d at 10 °C. During the first 5 d of storage, all UV-C treatments reduced deterioration as compared to the control. The treatment with 20 kJ/m² I/O was the most effective to reduce deterioration, and was used for further evaluations. In a second group of experiments, mature green bell pepper sticks were treated with 20 kJ/m² I/O, stored at 5 °C for 7 or 12 d and assessed for physical and chemical analysis, and microbiological quality. UV-C-treated fruit showed lower exudates and shriveling than the control. UV exposure also reduced decay, tissue damage, and electrolyte leakage. After 12 d at 5 °C, UV-C irradiated peppers remained firmer and had higher resistance to deformation than the control. The UV-C treatments also reduced weight loss and pectin solubilization. UV-C exposure decreased the counts of mesophile bacteria and molds, and did not affect acidity or sugars. UV-C-treated fruit stored for 0 or 7 d at 5 °C did not show major differences in antioxidants from the control as measured against DPPH(•) or ABTS(•)⁺ radicals. Results suggest that UV-C exposure is useful to maintain quality of refrigerated fresh-cut green pepper. Exposure to UV-C radiation before packing and refrigeration could be a useful nonchemical alternative to maintain quality and reduce postharvest losses in the fresh-cut industry. © 2012 Institute of Food Technologists®

  6. Avaliação da qualidade de mangas 'Tommy Atkins' minimamente processadas Quality evaluation of fresh-cut 'Tommy Atkins' mangoes

    Directory of Open Access Journals (Sweden)

    Brígida Monteiro Vilas Boas

    2004-12-01

    Full Text Available Visto que a popularidade de frutas e hortaliças minimamente processadas tem aumentado nos últimos anos devido aos aspectos de conveniência e qualidade, este trabalho teve por objetivo avaliar o efeito do ácido cítrico 1%, ácido ascórbico 1% e cloreto de cálcio 1% na conservação de mangas 'Tommy Atkins' minimamente processadas, armazenadas sob atmosfera modificada ativa (5% O2 + 5% CO2 e refrigeração por 12 dias. Foram realizadas as seguintes análises: acidez titulável, pH, sólidos solúveis totais, açúcares solúveis totais, vitamina C total, análise sensorial (sabor e análises microbiológicas (contagem de fungos filamentosos e leveduras e coliformes a 35 e 45ºC. Pode-se concluir que os tratamentos com ácido cítrico 1%, ácido ascórbico 1% e CaCl2 1% não influenciam na vida de prateleira das mangas 'Tommy Atkins' minimamente processadas. De acordo com a análise sensorial e microbiológica, a vida útil é de 12 dias a 5ºC.Since the popularity of fresh-cut fruits and vegetables has increased lately, due to the convenience and quality aspects, chemical modifications were investigated, in addition to sensory and microbiological aspects of fresh-cut the 'Tommy Atkins' mangoes were treated with 1% citric acid, 1% ascorbic acid and 1% calcium chloride stored under active modified atmospheres (5% O2 + 5% CO2 and refrigerated for 12 days. The following analyses were done: titratable acidity, pH, total soluble solids, total soluble sugars, C vitamin, sensory analysis (taste and microbiological analyses (filamentous fungus and yeast counting and coliforms at 35 e 45ºC. It was concluded that the treatments with 1% citric acid, 1% ascorbic acid and 1% CaCl2 didn't influence the shelf-life of the fresh-cut 'Tommy Atkins' mangoes. According to the sensory and microbiological analyses the useful life is 12 days at 5ºC.

  7. Efeito de diferentes temperaturas na qualidade de mandioquinha-salsa minimamente processada Effect of different temperatures on the quality of fresh-cut Peruvian carrot

    Directory of Open Access Journals (Sweden)

    Elisângela Elena Nunes

    2010-09-01

    Full Text Available O objetivo do presente trabalho foi avaliar a vida útil de mandioquinha-salsa 'Amarela de Senador Amaral' minimamente processada e armazenada em três temperaturas de armazenamento. As raízes foram descascadas manualmente, fatiadas (±1 cm de espessura, imersas em solução de dicloro isocianurato de sódio 100 mg L-1 por 15 minutos e acondicionadas em embalagem rígida de polipropileno (15 x 11,5 x 4,5 cm. As embalagens, contendo cerca de 150 g de raízes minimamente processadas, foram armazenadas a 0±1ºC, 5±1ºC ou 10±1ºC durante 15 dias, sendo realizadas análises a cada 3 dias. O delineamento experimental foi inteiramente casualizado em fatorial 3 x 6, sendo 3 temperaturas de armazenamento e 6 períodos de armazenamento, com 3 repetições. O armazenamento a 0ºC determinou, ao longo do armazenamento, aumento nos valores de L* e b*, menores valores de a*, menor atividade da peroxidase, polifenoloxidase, poligalacturonase, solubilização péctica e taxa respiratória, sendo a temperatura mais indicada para o armazenamento da mandioquinha-salsa 'Amarela de Senador Amaral' minimamente processada.The shelf life of fresh-cut Peruvian carrots 'Amarela de Senador Amaral', stored under three temperatures, was evaluated. The roots were peeled manually, sliced (±1 cm thick, immersed in a solution of sodium dichloroisocyanurate 100 mg L-1 during 15 minutes and packed in rigid polypropylene package (15 x 11.5 x 4.5 cm. The packages containing around 150 g of fresh cut roots were stored under 0±1ºC, 5±1ºC or 10±1ºC during 15 days. The analyses were performed every 3 days. The experimental design was completely randomized in a 3 x 6 factorial (3 storage temperature and 6 periods of storage, with three replicates. The storage at 0ºC provided higher L* and b* values, lower a* values, lower peroxidase, polyphenoloxidase and polygalacturonase activity, pectic solubilization and respiration rate. This temperature is the most proper for the

  8. 葡甘聚糖/蜂蜡复合液膜对鲜切琯溪蜜柚保鲜研究%Study on fresh-cut pomelo fresh-keeping by konjac glucomannan(KGM)-beeswax(BW)composite membrane

    Institute of Scientific and Technical Information of China (English)

    赖明耀; 兰润; 李雪晖; 庞杰

    2014-01-01

    该文研究室温(20℃)条件下葡甘聚糖/蜂蜡(KGM/BW)涂膜、葡甘聚糖(KGM)涂膜及对照组对鲜切琯溪蜜柚贮藏期间主要感观品质和理化性质影响。结果表明:KGM涂膜,尤其是KGM/BW涂膜能降低贮藏期间鲜切柚子的水分损失、抑制呼吸作用、减缓营养物质流失,具有良好的保鲜效果。%The effects of KGM/BW coating,KGM coating and the control group under the room temperature(20 ℃)on the sensory quality and physicochemical property of the fresh-cut honey pomelo(Guanxi)during postharvest storage were studied.The results showed that KGM/BW coating, compared to KGM coating group and the control,could protect the flesh-cut fruit best during storage from water loss and inhibit respiration as well as preserve the nutritious quality of the honey pomelo fruit.

  9. Fungal infections of fresh-cut fruit can be detected by the gas chromatography-mass spectrometric identification of microbial volatile organic compounds.

    Science.gov (United States)

    Lloyd, Steven W; Grimm, Casey C; Klich, Maren A; Beltz, Shannon B

    2005-06-01

    There is a large and rapidly growing market for fresh-cut fruit. Microbial volatile organic compounds indicate the presence of fungal or bacterial contamination in fruit. In order to determine whether microbial volatile organic compounds can be used to detect contamination before fruit becomes unmarketable, pieces of cantaloupe, apple, pineapple, and orange were inoculated with a variety of fungal species, incubated at 25 degrees C, then sealed in glass vials. The volatiles were extracted by headspace solid-phase microextraction and analyzed by gas chromatography-mass spectrometry. Forty-five compounds were identified that might serve as unique identifiers of fungal contamination. Fungal contamination can be detected as early as 24 h after inoculation.

  10. Characterisation of volatile profile and sensory analysis of fresh-cut "Radicchio di Chioggia" stored in air or modified atmosphere.

    Science.gov (United States)

    Cozzolino, Rosaria; Martignetti, Antonella; Pellicano, Mario Paolo; Stocchero, Matteo; Cefola, Maria; Pace, Bernardo; De Giulio, Beatrice

    2016-02-01

    The volatile profile of two hybrids of "Radicchio di Chioggia", Corelli and Botticelli, stored in air or passive modified atmosphere (MAP) during 12 days of cold storage, was monitored by solid phase micro-extraction (SPME) GC-MS. Botticelli samples were also subjected to sensory analysis. Totally, 61 volatile organic compounds (VOCs) were identified in the headspace of radicchio samples. Principal component analysis (PCA) showed that fresh product possessed a metabolic content similar to that of the MAP samples after 5 and 8 days of storage. Projection to latent structures by partial least squares (PLS) regression analysis showed the volatiles content of the samples varied depending only on the packaging conditions. Specifically, 12 metabolites describing the time evolution and explaining the effects of the different storage conditions were highlighted. Finally, a PCA analysis revealed that VOCs profile significantly correlated with sensory attributes.

  11. 鲜切果蔬微生物污染及控制研究进展%Research progress in control and microbial infection of fresh-cut fruits and vegetables

    Institute of Scientific and Technical Information of China (English)

    吴晓彬; 胡文忠; 刘程惠; 韩巍巍

    2011-01-01

    Microbial infection is one of the most important factors influencing quality of fresh-cut fruits and vegetables. In this paper,the sources and species of microbial,which effect on physiology of fresh-cut fruits and vegetables,were reviewed. The control methods on microbial of fresh-cut fruits and vegetables were introduced at home and abroad.%微生物侵染是影响鲜切果蔬品质的重要因素之一.本文概述了鲜切果蔬中微生物的污染来源、种类及其对鲜切果蔬组织生理的影响,并对国内外微生物的控制方法进行了介绍.

  12. Methodology for modeling the disinfection efficiency of fresh-cut leafy vegetables wash water applied on peracetic acid combined with lactic acid.

    Science.gov (United States)

    Van Haute, S; López-Gálvez, F; Gómez-López, V M; Eriksson, Markus; Devlieghere, F; Allende, Ana; Sampers, I

    2015-09-02

    A methodology to i) assess the feasibility of water disinfection in fresh-cut leafy greens wash water and ii) to compare the disinfectant efficiency of water disinfectants was defined and applied for a combination of peracetic acid (PAA) and lactic acid (LA) and comparison with free chlorine was made. Standardized process water, a watery suspension of iceberg lettuce, was used for the experiments. First, the combination of PAA+LA was evaluated for water recycling. In this case disinfectant was added to standardized process water inoculated with Escherichia coli (E. coli) O157 (6logCFU/mL). Regression models were constructed based on the batch inactivation data and validated in industrial process water obtained from fresh-cut leafy green processing plants. The UV254(F) was the best indicator for PAA decay and as such for the E. coli O157 inactivation with PAA+LA. The disinfection efficiency of PAA+LA increased with decreasing pH. Furthermore, PAA+LA efficacy was assessed as a process water disinfectant to be used within the washing tank, using a dynamic washing process with continuous influx of E. coli O157 and organic matter in the washing tank. The process water contamination in the dynamic process was adequately estimated by the developed model that assumed that knowledge of the disinfectant residual was sufficient to estimate the microbial contamination, regardless the physicochemical load. Based on the obtained results, PAA+LA seems to be better suited than chlorine for disinfecting process wash water with a high organic load but a higher disinfectant residual is necessary due to the slower E. coli O157 inactivation kinetics when compared to chlorine.

  13. Study on Color Protective Treatment of Fresh-cut Yacon%鲜切雪莲果护色效果的研究

    Institute of Scientific and Technical Information of China (English)

    蔡文韬; 夏延斌

    2012-01-01

    研究不同褐变抑制剂对鲜切雪莲果护色效果,通过正交试验并运用多指标试验设计综合加权评分法对多种抑制剂护色效果的进行综合选优.试验结果表明:采用0.5%柠檬酸+0.5%抗坏血酸+0.05‰焦亚硫酸钠浸泡10min的复合处理,试验综合加权评分值为97.6414.雪莲果的PPO活性为0.007、褐变度为3.62、感官品质为7,在10d内抑制褐变效果最好.%The effects of different inhibitors on fresh-cut yacon were studied. It was optimized comprehensively for a variety of protect color inhibitors through orthogonal experiment and using multi-index experimental design and weighted score. The results showed that the optimum combination treatment was 0.5% citric acid +0.5%ascorbic acid +0.05%o sodium pyrosulfite, and the optimum time for the fresh-cut yacon dipping in the solution was 10 min. After the treatment, the value of fi was of 97.6414; the PPO activity was of 0.007; BD value was of 3.62; the quality of appearance was of 7; and the best color protective effect was found within l0d.

  14. Modelling growth of Escherichia coli O157:H7 in fresh-cut lettuce submitted to commercial process conditions: chlorine washing and modified atmosphere packaging.

    Science.gov (United States)

    Posada-Izquierdo, Guiomar D; Pérez-Rodríguez, Fernando; López-Gálvez, Francisco; Allende, Ana; Selma, María V; Gil, María I; Zurera, Gonzalo

    2013-04-01

    Fresh-cut iceberg lettuce inoculated with Escherichia coli O157:H7 was submitted to chlorine washing (150 mg/mL) and modified atmosphere packaging on laboratory scale. Populations of E. coli O157:H7 were assessed in fresh-cut lettuce stored at 4, 8, 13 and 16 °C using 6-8 replicates in each analysis point in order to capture experimental variability. The pathogen was able to grow at temperatures ≥8 °C, although at low temperatures, growth data presented a high variability between replicates. Indeed, at 8 °C after 15 days, some replicates did not show growth while other replicates did present an increase. A growth primary model was fitted to the raw growth data to estimate lag time and maximum growth rate. The prediction and confidence bands for the fitted growth models were estimated based on Monte-Carlo method. The estimated maximum growth rates (log cfu/day) corresponded to 0.14 (95% CI: 0.06-0.31), 0.55 (95% CI: 0.17-1.20) and 1.43 (95% CI: 0.82-2.15) for 8, 13 and 16 °C, respectively. A square-root secondary model was satisfactorily derived from the estimated growth rates (R(2) > 0.80; Bf = 0.97; Af = 1.46). Predictive models and data obtained in this study are intended to improve quantitative risk assessment studies for E. coli O157:H7 in leafy green products. Copyright © 2012. Published by Elsevier Ltd.

  15. 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.

  16. Quality of fresh-cut avocado (Persea americana Mill. stored under different temperatures Qualidade de abacates (Persea americana Mill. minimally processados armazenados sob diferentes temperaturas

    Directory of Open Access Journals (Sweden)

    Ana Carla Marques Pinheiro

    2009-08-01

    Full Text Available The goal of this work was to evaluate the effect of different storage temperatures on the quality maintenance of fresh-cut 'Fortuna' avocado (Persea americana Mill.. The fruit was selected, washed and sanitized with sodium hypochlorite solution (190 ppm total residual chlorinee for 15 minutes. After that, the tip was cut and the fruit was also cut in halves, peeled and the pit removed, manually. Then the halves were immersed in 0.5% calcium chlorite + 0.5% cysteine solution for 2 minutes, to avoid darkening and packed in rigid plastic covered with 20 micrometer thick plastic wrap (PVC film with a permeability to O2, CO2 and water vapor of 15,000, 80,000 and 390 cm³/m²/day, respectively. The product was stored under 3 different temperatures 0, 5, 10ºC and evaluated at 5 different storege periods of 0, 2, 3, 5 and 6 days, in a randomized design in a 3x5 factorial. The storage of fresh-cut avocado at 5ºC is the best alternative because it determines better maintenance of quality of the avocado. These presented lower darkening of pulp, better scores for appearance and acceptability, lower softening and polyphenoloxidase activity, in comparison to those stored at 0 and 10ºC. The fresh-cut avocados stored at 5ºC presented a shelf life of 5 days, based, mainly on, appearance, score 7.3, sited between the concepts "like moderately" and "like very much" on a hedonic scale of 9 points and 86% of acceptability, at the end of 5 days of storage.Objetivou-se avaliar o efeito de diferentes temperaturas de armazenamento na manutenção da qualidade de abacates 'Fortuna' (Persea americana Mill. minimally processados. Os frutos foram lavados e sanificados em solução de hipoclorito de sódio (190 ppm de cloro residual total por 15 minutos. Posteriormente, efetuou-se a retirada da extremidade onde se insere o pedúnculo, o corte em metades, retirada do caroço e casca, manualmente. Em seguida, as metades foram imersas em solução com cloreto de cálcio 0

  17. Cellulose-silver nanoparticle hybrid materials to control spoilage-related microflora in absorbent pads located in trays of fresh-cut melon.

    Science.gov (United States)

    Fernández, Avelina; Picouet, Pierre; Lloret, Elsa

    2010-08-15

    The antimicrobial activity of newly developed cellulose-silver nanoparticle hybrid materials was investigated during storage of minimally processed "Piel de Sapo" melon. Silver nanoparticles were produced after in-situ reduction by physical methods of 1% silver nitrate adsorbed on cellulose fibres; they accounted between 5 and 35 nm diameter, and were not aggregated. Fresh-cut melon pieces were stored for 10 days at 4 degrees C under natural modified atmosphere packaging, in presence or absence of silver loaded absorbent pads. The evolution of headspace gas composition, quality parameters, and the antimicrobial activity against spoilage-related microorganisms were investigated. The cellulose-silver nanoparticle hybrid materials released silver ions after melon juice impregnated the pad. The released silver ions were particularly useful to control the population of spoilage-related microorganisms in cellulose based absorbent pads in contact with vegetable matrices, showing a low chelating effect against silver ions; the lag phases of the microorganisms were considerably incremented and microbial loads in the pads remained in average approx. 3 log(10) CFU/g below the control during the investigated storage period. Furthermore, the presence of silver loaded absorbent pads retarded the senescence of the melon cuts, presenting remarkably lower yeast counts, lower degrees Brix values, and a juicier appearance after 10 days of storage.

  18. Influência do tipo de corte na qualidade de abobrinha 'Menina Brasileira' minimamente processada Influence of cut type on quality of cv. 'Menina Brasileira' summer squash fresh-cut

    Directory of Open Access Journals (Sweden)

    Brígida M Vilas Boas

    2006-06-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito do tipo de corte na manutenção da qualidade de abobrinhas 'Menina Brasileira' minimamente processadas armazenadas sob refrigeração. As abobrinhas foram fatiadas ou raladas, sendo sanificadas com solução de hipoclorito de sódio 50 mg L-1 por 10 minutos. Estas foram acondicionadas em bandejas de polipropileno envoltas com filme de PVC (0,020 mm de espessura, e armazenadas em câmara fria (6ºC e 95% UR por 12 dias. As seguintes variáveis foram avaliadas: perda de massa, pH, sólidos solúveis (SS, valores L*, C* e hº, aparência e cor. O experimento foi conduzido em delineamento inteiramente casualizado em esquema fatorial (2x5, sendo dois tipos de corte (fatiada e ralada e cinco tempos de armazenamento (0, 3, 6, 9 e 12 dias. A perda de massa foi pequena, atingindo valores máximos de 1,5% para a abobrinha ralada. Os valores de pH foram menores a partir do 6º dia nas abobrinhas raladas quando comparadas às fatiadas. Após o 3º dia de armazenamento, as abobrinhas raladas apresentaram menores valores de SS em relação às abobrinhas fatiadas. Maiores valores L* foram encontrados nas abobrinhas fatiadas, observando-se um acréscimo ao longo do armazenamento. Abobrinha fatiada apresentou menores perdas de coloração, baseado nos valores h° e C* e melhor aceitabilidade quando avaliada sensorialmente em relação à ralada, com decréscimos nas notas com o armazenamento. O tipo de corte influencia a vida de prateleira de abobrinha minimamente processada sendo que as formas fatiada e ralada mantêm a aparência e as características físico-químicas até o 12º dia de armazenamento.The goal of this work was to evaluate the effect of the type of cut the on maintenance quality of fresh-cut 'Menina Brasileira' summer squash stored under refrigeration. Summer squashes were sliced or grated and sanitized with sodium hypochloride solution at 50 mg L-1 for 10 minutes. They were placed in

  19. Qualidade e vida útil de pequi minimamente processado armazenado sob atmosfera modificada Quality and shelf life of fresh-cut peki stored under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Éllen Cristina de Souza

    2007-12-01

    Full Text Available Objetivou-se neste trabalho avaliar a eficiência do uso de atmosfera modificada passiva e ativa na manutenção da qualidade e prolongamento da vida útil de pequi minimamente processado armazenado a 5ºC, por 12 dias, através de avaliações fisiológicas, físicas, físico-químicas e químicas. Os pequis foram lavados em água corrente e sanificados antes e após a retirada da casca em solução de hipoclorito de sódio 200 mg.L-1 e 100 mg.L-1, por 15 e 5 minutos, respectivamente. Os pequis foram acondicionados em embalagem rígida de polipropileno (PP, da seguinte forma: coberta com tampa do mesmo polímero; envolta com filme de policloreto de vinila (PVC 0,014 mm; selada passiva e ativamente (3,2% O2 + 9,2% CO2 e (7,7% O2 + 3,9% CO2 com filme de polietileno (PE + PP 0,060 mm. Conclui-se que as embalagens rígidas seladas passiva e ativamente com filme de PE + PP 0,060 mm não são recomendadas para acondicionar pequi minimamente processado, em razão do nível de O2 estar próximo a 0%, no terceiro dia de armazenamento, o que compromete a sua qualidade. As embalagens rígidas de polipropileno com tampa do mesmo polímero e as envoltas com filme de PVC são as mais indicadas para pequi minimamente processado, visto que não propiciam condições de anaerobiose e nem alteraram expressivamente suas características físicas, físico-químicas e químicas, resultando em uma vida útil de 12 dias de armazenamento a 5 ± 1ºC e UR 90 ± 5%.The aim of this work was to evaluate the efficiency of the use of passive and active modified atmosphere on the maintenance of quality and prolongation of the shelf life of fresh-cut peki fruit stored at 5ºC, for 12 days, through physiological, physical, physico-chemistry and chemistry evaluations. Peki fruit were washed with stream water and sanitized with sodium hypochlorite 200 and 100 mg.L-1, for 15 and 5 minutes, before and after peeling, respectively. Peki fruit were packed into rigid propylene package

  20. Determination of six parabens residues in fresh-cut vegetables using QuEChERS with multi-walled carbon nanotubes and high performance liquid chromatography-tandem mass spectrometry

    Science.gov (United States)

    In this study, an optimized QuEChERS sample preparation method was developed to analyze residues of six parabens: methyl-, ethyl-, n-propyl-, isopropyl-, n-butyl-, and isobutyl-paraben in five fresh-cut vegetables (potato, broccoli, carrot, celery and cabbage) with high performance liquid chromatogr...

  1. Combined effects of thermosonication and slightly acidic electrolyzed water on the microbial quality and shelf life extension of fresh-cut kale during refrigeration storage.

    Science.gov (United States)

    Mansur, Ahmad Rois; Oh, Deog-Hwan

    2015-10-01

    This study evaluated the efficacy of thermosonication combined with slightly acidic electrolyzed water (SAcEW) on the shelf life extension of fresh-cut kale during storage at 4 and 7 °C. Each kale (10 ± 0.2 g) was inoculated to contain approximately 6 log CFU/g of Listeria monocytogenes. Each inoculated or uninoculated samples was dip treated at 40 °C for 3 min with deionized water, thermosonication (400 W/L), SAcEW (5 mg/L), sodium chlorite (SC; 100 mg/L), sodium hypochlorite (SH; 100 mg/L), and thermosonication combined with SAcEW, SC, and SH (TS + SAcEW, TS + SC, and TS + SH, respectively). Growths of L. monocytogenes and spoilage microorganisms and changes in sensory (overall visual quality, browning, and off-odour) were evaluated. The results show that lag time and specific growth rate of each microorganism were not significantly (P > 0.05) affected by treatment and storage temperature. Exceeding the unacceptable counts of spoilage microorganisms did not always result in adverse effects on sensory attributes. This study suggests that TS + SAcEW was the most effective method to prolong the shelf life of kale with an extension of around 4 and 6 days at 4 and 7 °C, respectively, and seems to be a promising method for the shelf life extension of fresh produce.

  2. Study on the control of enzymatic browning in fresh-cut sweet potatoes%鲜切甘薯酶促褐变调控的研究

    Institute of Scientific and Technical Information of China (English)

    程双; 胡文忠; 马跃; 刘程惠

    2011-01-01

    Fresh-cut sweet potatoes were treated with different concentrations of D-sodium erythorbate and citric acid,study on the reaction of enzymatic browning at 10℃, it revealed the regulation mechanism of different browning inhibitor on fresh-cut sweet potatoes.The results indicated that 0.5%-1.5% of D-sodium erythorbate and 0.01%~0.03% citric acid delayed the occurrence of enzymatic browning, the activities of PPO and POD were inhibited effectively,the content of total phenolic was reduced.But the enzymatic browning was accelerated with the treatment of high-concentration citric acid( ≥0.05% ).Compared with the two browning inhibitor,the inhibition of D-sodium erythorbate was more effectively,the optimum concentration was 1.0%.%采用不同浓度的D-异抗坏血酸钠和柠檬酸分别处理鲜切甘薯,研究其在10℃贮藏过程中的酶促褐变反应,揭示不同褐变抑制剂对鲜切甘薯酶促褐变的调控机制.结果表明,0.5%~1.5%D-异抗坏血酸钠和低浓度(0.01%~0.03%)柠檬酸均延缓了鲜切甘薯酶促褐变的发生,有效抑制了PPO和POD的活性,降低了总酚含量;但高浓度(≥0.05%)柠檬酸处理反而加速了酶促褐变反应的进行.比较两种褐变抑制剂,D-异抗坏血酸钠抑制效果更好,其最佳浓度为1.0%.

  3. Effect of modified atmosphere and vacuum packaging on selected chemical parameters of rainbow trout (Oncorhynchus mykiss and carp (Cyprinus carpio cuts freshness

    Directory of Open Access Journals (Sweden)

    Babić Jelena A.

    2014-01-01

    vacuum was established during the whole period of investigation (p < 0,001, while in carp cuts samples packaged in vacuum the increase in pH value (p < 0,05 was established up to 7th day of testing. Based on the obtained results it can be concluded that gas mixture consisting of 60% CO2 and 40% N2 was the most suitable for packaging of fresh trout and carp cuts in terms of selected chemical parameters, such as TVB-N and pH. [Projekat Ministarstva nauke Republike Srbije, br. TR 31011 i br. TR 31075

  4. Utilization of physicochemical variables developed from changes in sensory attributes and consumer acceptability to predict the shelf life of fresh-cut mango fruit.

    Science.gov (United States)

    Salinas-Hernández, Rosa María; González-Aguilar, Gustavo A; Tiznado-Hernández, Martín Ernesto

    2015-01-01

    Sensory evaluation is the ideal tool for shelf-life determination. With the objective to develop an easy shelf-life indicator, color (L*, a*, b*, chroma and hue angle), total soluble solids (TSS), firmness (F), pH, acidity, and the sensory attributes of appearance, brightness, browning, odor, flavor, texture, color, acidity and sweetness were evaluated in fresh cut mangoes (FCM) stored at 5, 10, 15 and 20 °C. Overall acceptability was evaluated by consumers. Correlation analysis between sensory attributes and physicochemical variables was carried out. Physicochemical cut-off points based on sensory attributes and consumer acceptability was obtained by regression analysis and utilized to estimate FCM shelf-life by kinetic models fitted to each variable. The validation of the model was done by comparing the shelf life estimated by kinetic models and consumers. It was recorded large correlations between appearance, brightness, and color with L*; appearance and color with chroma and hue angle; sweetness and flavor with TSS, and between F and texture. The shelf life estimated based on consumer using a 9 point hedonic scale was in the range of 10-12, 2.3-2.6, 1.3-1.5 and 1.0-1.1 days for 5, 10, 15 and 20 °C. It was recorded large correlation coefficients between the shelf life estimated by consumer acceptability scores and physicochemical variables. Kinetic models based on physicochemical variables showed a tendency to overestimate the shelf life as compared with the models bases on the sensory attributes. It was concluded that physicochemical variables can be used as a tool to estimate the FCM shelf life.

  5. 低温贮藏对鲜切富士苹果褐变的影响%Effects of Storage Temperature on Browning of Fresh-cut 'Fuji' Apples

    Institute of Scientific and Technical Information of China (English)

    魏敏; 周会玲; 陈小利; 辛付存

    2011-01-01

    The effects on browning and the enzymatic activity of fresh-cut 'Fuji' apples during the storage at 2℃, 6℃and 10℃, respectively were investigated. The results showed that low temperature could delay the browning and senescence of fresh-cut apple by inhibiting the activities of PPO and POD. At the same time, it kept high quality of fresh-cut apple by restraining the increase of MDA and total phenolic contents, reducing the activity of PAL. Under 6'C, the occurrence of browning could be effectively suppressed and the damage of fresh-cut 'Fuji' apple could also be lowered, which maintained the quality of fresh-cut fruit appearance.%研究了鲜切富士苹果在2、6℃和10℃贮藏下的褐变情况及相关酶活性.结果表明:低温冷藏可抑制多酚氧化酶(PPO)、过氧化氢酶(POD)活性,延缓鲜切富士苹果的褐变和衰老;同时冷藏抑制了丙二醛(MDA)含量和总酚含量的上升,降低苯丙氨酸解氨酶(PAL)的活性,保持鲜切富士苹果较高品质.与其他2个温度处理相比,在6℃条件下贮藏鲜切富士苹果,不仅可以有效地抑制褐变的发生,还可以降低温度过低导致对鲜切果体的伤害,从而较好地保持鲜切富士的外观品质.

  6. Métodos de conservação aplicados a melão minimamente processado Conservation methods applied to fresh-cut melon

    Directory of Open Access Journals (Sweden)

    Anaí Peter Batista

    2013-05-01

    Full Text Available O objetivo desta revisão é apresentar alguns métodos de conservação que podem ser utilizados para prolongar a vida útil do melão minimamente processado. Dentre os métodos, serão abordados revestimento comestível, irradiação, antimicrobianos naturais, antioxidantes, agentes de firmeza, atmosfera modificada, branqueamento, luz ultravioleta e alta pressão. Dependendo do método pode haver redução das alterações associadas ao processo mínimo do melão, como a perda de água, alteração da cor e firmeza, alteração do metabolismo e crescimento de micro-organismos, sendo o resultado muitas vezes dependente da cultivar do melão utilizado.The objective of this review is to present some conservation methods that can be used to prolong the life of fresh-cut melon. Among the methods, edible coating, irradiation, natural antimicrobials, antioxidants, firmness agent, modified atmosphere, whitening, ultraviolet light and high pressure will be discussed. Depending on the method, the changes associated to minimum process of melon, such as water loss, change in color and firmness, change in the metabolism and growth of micro-organisms can be reduced and the result is often dependent on the melon cultivar used.

  7. 鲜切雪莲果防褐绿变工艺研究%The Anti-green and Browning Technology for Fresh-cut Yacon

    Institute of Scientific and Technical Information of China (English)

    蔡文韬; 夏延斌; 张音

    2011-01-01

    以雪莲果为试材,研究鲜切雪莲果防褐绿变的工艺.实验中比较了不同护色处理方法的护色效果,采用正交实验筛选出鲜切雪莲果的最佳组合护色条件,雪莲果最优组合防褐绿变的工艺为0.1%CaCl2,0.15%柠檬酸,浸泡30min,在.21℃下冻藏7d,未见褐变和绿变.%Yacon was as experimental material to study the anti-enzymatic browning and greening process. By comparing the different treatment effect of the color-protecting methods, the best color-protecting combination technology of fresh-cut Yacon was determined by orthogonal experiments as: 0.1% calcium chloride, 0.15% citric acid, and soaked time 30 min. The color is little changed at -21℃ in 7 days.

  8. Evaluation of HACCP system implementation on the quality of mixed fresh-cut salad prepared in a university canteen: a case study.

    Science.gov (United States)

    Osimani, Andrea; Aquilanti, Lucia; Clementi, Francesca

    2015-01-01

    The increasing awareness that foods can represent vehicles for health risk factors has caused scientists and public authorities to multiply their efforts to reduce these risks to within acceptable limits. Nevertheless, some challenging issues still remain unsolved and new ones have recently emerged, such as the increase in outbreaks of foodborne diseases originating from the consumption of meals at catering facilities. The study described in this article was aimed at evaluating the microbiological quality of mixed fresh-cut salads at an Italian university canteen operating in conformity with the hazard analysis and critical control point (HACCP) system. The effectiveness of the preventive and corrective measures taken was also assessed with respect to the frequency of unsatisfactory salad samples. During the investigation, E. coli, Salmonella spp., and Listeria monocytogenes were never detected. By contrast, a high number of samples exceeded the mandatory or suggested limits for food processing hygiene (in terms of mesophilic aerobes, coliforms, Staphylococcus aureus, Bacillus cereus, and sulfite-reducing clostridia counts). Despite the introduction of a series of preventive and corrective actions, the results were only partially satisfactory; this was most likely due to the impossibility of having available an adequate level of human resources that are indispensable to correctly putting the HACCP procedures into daily practice.

  9. Qualidade de mandioquinha-salsa minimamente processada e armazenada sob atmosfera modificada Quality of fresh-cut peruvian carrot: use of modified atmosphere

    Directory of Open Access Journals (Sweden)

    Elisângela Elena Nunes

    2009-10-01

    para prolongar a vida útil de mandioquinhas-salsa minimamente processadas, preservando seus atributos de qualidade. Diante da avaliação sensorial realizada, a aparência e a cor das fatias de mandioquinha-salsa mantiveram-se aceitáveis para o consumo até o final do período de armazenamento.The aim of this research was to verify the effect of the passive and active modified atmosphere on the conservation of fresh-cut peruvian carrot, cv. Amarela de Senador Amaral, purchased from a commercial crop of Lavras, MG, Brazil. The roots were screened, washed with neutral detergent and rinsed in running water. Afterwards, they were immersed into a solution of 300mg L-1 sodium hypochlorite for 15 minutes and dried at room temperature. The roots were peeled and cut in slices of about 1cm of thickness and immersed into a solution of 50mg L-1 sodium hypochlorite for 10 minutes, drained in plastic sieves and packed. The trays containing the slices of Peruvian carrot were stored in a cold room (5±1°C and 98% RH for 15 days. The following analyses were performed every 3 days: : pH, titrable acidity, total soluble solids, firmness, L* and b* values, starch and sensorial evaluation (appearance and color. The experimental design was completely randomized (CRD in a 3 x 6 factorial scheme, with 3 sorts of atmospheres (passive; active with initial injection of the mixtures: 2% O2 + 10% CO2 e 5% O2 + 5% CO2 and 6 times of storage (0, 3, 6, 9, 12 and 15 days with 3 replicates. The average values of pH, titrable acidity, soluble solids and firmness found in this work were 6.79, 0.13% of malic acid, 4.04°Brix and 5.17 N, respectively. The active modified atmosphere (5% de O2 + 5% CO2 determined higher L* value to the fresh cut Peruvian carrots at the sixth and twelfth day of storage as compared with the active (2% of O2 + 10% CO2. The active modified atmosphere with 5% O2 + 5% CO2 determined higher b* values and starch contents to the slices of Peruvian carrots as compared with the

  10. 没食子酸丙酯、壳聚糖对鲜切生姜保鲜特性的影响%Effects of Propyl Gallate and Chitosan on Preservation of Fresh-cut Ginger During Storage

    Institute of Scientific and Technical Information of China (English)

    丁君; 吴昊; 王成荣

    2016-01-01

    In this experiment,the effects of propyl gallate (PG)and chitosan on preservation of fresh-cut ginger during storage are investigated. Select gingers without scab and mechanical deterioration as test materials.The gingers are cut into 5 mm-thickness sheets after rinsing and peeling.The fresh-cut gingers are socked with three different treatments,including 0.20% PG, 1.50% chitosan and 0.20% PG+1.50% chitosan,and fresh-cut gingers without any reagent are used as control.The fresh-cut gingers are stored at 14 ℃ (± 1.0 ℃),then the changes of weight loss, browning degree,POD activity,MDA content,Vc content,hardness,elasticity and chewiness of fresh-cut gingers are determined.The results show that the three different treatments could delay the rise of weight loss and MDA content with a certain degree,reduce the browning speed,and inhibit the POD activity.At the same time,three different treatments could maintain the hardness and Vc content of fresh-cut gingers at a higher level and the chewiness and elasticity of fresh-cut gingers at a lower level.Compare with 0.20% PG and 1.50% chitosan,the effect of 0.20% PG + 1.50%chitosan treatment on preservation of fresh-cut ginger is the best.%试验研究了没食子酸丙酯(PG)、壳聚糖对鲜切生姜保鲜效果的影响。挑选无病虫害、无机械损伤的生姜,清洗去皮,用不锈钢刀切分成5 mm 薄片,用0.20% PG,1.50%壳聚糖和0.20% PG+1.50%壳聚糖3个不同溶液浸泡处理,以未加处理的鲜切生姜为对照组,在14℃(±1.0℃)恒温库中贮藏,每隔3天测定其失重率、褐变度、过氧化物酶(POD)活力、丙二醛含量、Vc 含量、硬度、弹性以及咀嚼性的变化。结果表明:3种不同处理均能够在一定程度上延缓鲜切生姜失重率和丙二醛含量的升高,降低鲜切生姜的褐变速率,抑制 POD 活性;同时,3种不同处理均使得鲜切生姜的 Vc 含量和硬度维持在较高水平,而其咀嚼性和弹性保持在较低水平。3

  11. Changes in bioactive compounds and oxidative enzymes of fresh-cut pomegranate arils during storage as affected by deficit irrigation and postharvest vapor heat treatments.

    Science.gov (United States)

    Peña-Estévez, María E; Gómez, Perla A; Artés, Francisco; Aguayo, Encarna; Martínez-Hernández, Ginés Benito; Galindo, Alejandro; Torecillas, Arturo; Artés-Hernández, Francisco

    2016-12-01

    The effect of postharvest vapor heat treatments at 95℃ (4, 7, and 10 s) regarding a conventional sanitizing treatment with 100 mg NaClO l(-1) on enzyme activities (phenylalanine ammonia lyase, polyphenol oxidase, and peroxidase), phenolic content, and total antioxidant capacity of fresh-cut pomegranates arils throughout 18 days at 5℃ was studied. Furthermore, the effect of two sustained deficit irrigation (SDI) strategies, compared to a standardly irrigated control (CTRL), was also studied on such quality parameters throughout storage. Arils from CTRL-irrigated fruit registered phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase initial activities of 60.6, 382, and 14.4 U g(-1) fw, respectively. Arils from sustained deficit irrigation fruit registered 46-58% lower phenylalanine ammonia lyase values while polyphenol oxidase and peroxidase activities did not register great variants (fruit although no great peroxidase and polyphenol oxidase (fruit registered higher phenolic content than those values reported for CTRL samples. However, phenolic compounds decreased during storage, in a greater extent for sustained deficit irrigation samples, although 7 s arils achieved better phenolic compounds retention in sustained deficit irrigation samples. Vapor heat treatments reduced up to twofold the total antioxidant capacity losses observed in samples sanitized by conventional NaOCl treatment during shelf life. Conclusively, postharvest vapor heat treatment for 7 and 10 s used to extend the shelf life of pomegranate arils up to 18 days at 5℃ reduced the losses of health-promoting compounds during storage compared to conventional NaOCl sanitizing treatment. © The Author(s) 2016.

  12. Inibição do escurecimento enzimático de banana maçã minimamente processada Enzimatic browning inhibition of fresh-cut apple banana

    Directory of Open Access Journals (Sweden)

    Ânderson Adriano Martins Melo

    2006-03-01

    Full Text Available Objetivou-se, neste trabalho, avaliar o efeito do ácido ascórbico (AA, do cloreto de cálcio (CC, do cloridrato de L-cisteína (Cis e EDTA, na prevenção do escurecimento enzimático de banana maçã minimamente processada. Foram utilizadas as combinações: (i AA 1%+CC 1%+Cis 0,5%, (ii AA 1%+CC 1%+Cis 1%, (iii AA 1%+CC 1%+Cis 1,5% e (iv EDTA 1%, constituindo quatro tratamentos de um delineamento inteiramente casualizado. Produtos minimamente processados não tratados quimicamente não foram analisados, considerando-se seu acentuado escurecimento e sua vida de prateleira inferior a 6 h. As bananas foram tratadas com hipoclorito de sódio, fatiadas, imersas nos tratamentos químicos, acondicionadas em embalagens rígidas envoltas com filme PVC 30 µm e armazenadas durante cinco dias a 5+1°C e 85+3% UR. Amostras foram analisadas diariamente, durante os cinco dias de armazenamento. Os tratamentos contendo AA 1%+CC 1%+Cis 1% e AA 1%+CC 1%+Cis 1,5% determinaram os maiores valores de acidez titulável e menores de pH. Observaram-se aumentos no valor a* e redução nos valores b* e L* na banana maçã minimamente processada, independente do tratamento químico, durante o armazenamento. O tratamento AA 1%+CC 1%+Cis 1,5% foi o mais efetivo na prevenção das modificações dos valores a*, b* e L*, associados à coloração das rodelas. Observou-se aumento na atividade da polifenoloxidase (PPO e peroxidase (POD durante o armazenamento das rodelas de banana, independente do tratamento, à exceção da redução observada na atividade da PPO, nos produtos tratados com EDTA. Os tratamentos contendo EDTA e AA 1%+CC 1%+Cis 1,5% foram os mais efetivos na contenção do aumento das atividades da PPO e POD, respectivamente.The goal of this work was to evaluate the effect of ascorbic acid (AA, calcium chloride (CC, L-cysteine hydrochloride (Cys and EDTA on prevention of enzymatic browning of fresh-cut apple banana. The following combinations were used: (i AA 1

  13. The Research Progress on Inhibition of Fresh-cut Fruits and Vegetable Enzymatic Bromning%鲜切果蔬酶促褐变控制研究进展

    Institute of Scientific and Technical Information of China (English)

    胡晓露; 缪丽华

    2012-01-01

    褐变是影响鲜切果蔬外观品质的一个重要因素。本文介绍了抑制鲜切果蔬酶促褐变的物理、化学等方法。旨在为以后的研究提供一定的依据。%Enzymatic browning is one of important factors impacting quality of fresh-cut fruits and vegetables. Physical inhibition ways and chemical inhibition methods of fresh-cut fruits and vegetable enzym atic browning is reviewed in this text. This study is designed to providing reference to the de'velopment of longan drying.

  14. Studied on the Best Conditions of Fresh-cut Sweet Peppers Storage with Modified Atmosphere Packaging%气调包装保鲜鲜切甜椒最优条件的研究

    Institute of Scientific and Technical Information of China (English)

    高元元

    2012-01-01

    鲜切果蔬具有品质新鲜、食用方便、营养丰富等特点.其生产过程不进行剧烈的加热灭菌和杀酶防褐等处理,且产品包装时不是绝氧的,故产品是“新鲜”的.与原始性状的果蔬相比,它既新鲜洁净又方便省时,具有广阔的发展前途.为了提高鲜切甜椒的贮藏保鲜品质.根据包装袋厚度、温度和装载量三个因素设计正交试验表,通过感官评定、褐变指数、货架期实验得出气调包装保鲜鲜切甜椒的最佳组合.实验表明,最好的组合为0.02mmPE袋(30×40cm),5℃,200g装载量,使鲜切甜椒的货架期达到258h,为实验中的最高值.为鲜切甜椒气调包装保鲜提供了一种简便易行的方法,而且为气调包装在其它鲜切果蔬保鲜方面实现产业化开发应用提供理论和实践的依据.%Fresh-cut fruits and vegetables are charactered by good fresh quality and eating convenience with rich nutrition. Its production process doesn't carry on fierce heated up antiseptic and killed the enzyme to inhibit browning and so on, also when product packaging is not certainly the oxygen isolation, therefore the product is "fresh". Through the comparison with the original characters of fruits and vegetables, they were both fresh and facilitation time-saving, and had a broad development future. It was shown in this study that the quality of fresh-cut sweet peppers was enhanced by storing at PE films. The organoleptic evaluation, browning index and shelf life were evaluated. Through the experiment the best condition of modified atmosphere packaging was obtained which maintained freshness of fresh-cut sweet peppers. The experiment indicated that, the best condition was the 0.02mm PE film (30x40cm), 5℃, 200g packaging capacity. Fresh-cut sweet peppers' shelf-life to achieve 258h was maximum in experiment. The research provided one method which was simple and easy for fresh-cut sweet peppers' modified atmosphere packaging, and supplied the

  15. 涂膜处理对鲜切山药褐变及抗氧化性的影响%Effect of Coating on Browning and Antioxidant Activity of Fresh-Cut Yam

    Institute of Scientific and Technical Information of China (English)

    马利华; 秦卫东; 陈学红; 王磊

    2012-01-01

    为保持鲜切山药的色泽及抗氧化性,延长其货架期,研究壳聚糖、卡拉胶、海藻酸钠及复合涂膜剂对鲜切山药涂膜处理后,在5℃贮藏期间褐变及抗氧化性的影响。结果表明:壳聚糖1.57%+卡拉胶0.9%+海藻酸钠1.55%涂膜后,鲜切山药储存期间,可明显降低山药的褐变程度及抑制PPO的比活力,防止贮藏后期酚类物质的氧化,提高鲜切山药的整体抗氧化能力。%In order to preserve the color and antioxidant activity of fresh-cut yam and extend its shelf life, the effects of different types of coating treatment (chitosan alone, carrageenan alone, sodium alginate alone, and all of them) on browning degree and antioxidant activity of fresh-cut yam during storage at 5 ℃ were investigated. The results showed that a mixture of 1.57% chitosan, 0.9% carrageenan and 1.55% sodium alginate could inhibit PPO activity and reduce the browning degree of fresh-cut yam during storage, and prevent polyphenol oxidation and increase the total antioxidant activity of fresh-cut yam during the late period of storage.

  16. 不同质量浓度臭氧化水对鲜切西兰花贮藏品质的影响%Effect of Ozonated Water with Various Concentrations on Storage Quality of Fresh-cut Broccoli

    Institute of Scientific and Technical Information of China (English)

    王宏延; 曾凯芳; 贾凝; 陈存坤; 王文生

    2012-01-01

    采用不同质量浓度臭氧化水处理鲜切西兰花。结果表明:质量浓度2.0mg/L的臭氧化水处理组保鲜效果最优,在贮藏12d时与对照组相比,质量损失率降低24.37%,VC含量提高40.7%,多酚氧化酶酶活降低23.5%,过氧化物酶酶活降低25.6%;在4℃的条件下,质量浓度2.0mg/L的臭氧化水处理组鲜切西兰花贮藏期可达到15d。%Ozonated water can be used for disinfection,sterilization,deodorization and preservation with multiple advantages such as rapid sterilization rate,simple operation and without residues.It can be used directly for the sterilization of fresh-cut vegetables so that it is a potential technology of cold sterilization and green sterilization.The results showed that the best preservation effect on fresh-cut broccoli was observed at the condition of 2 mg/L ozonated water.Compared with the control,ozonated water-treated fresh-cut broccoli after storage for 12 days revealed a reduction by 24.37% for weight loss rate,an improvement by 40.7% for vitamin C,a decline by 23.5% for polyphenol oxidase activity and a decrease by 25.6% for peroxidase activity.The storage life of fresh-cut broccoli subjected to treatment with 2 mg/L ozonated water can be extended to 15 days at the storage temperature of 4 ℃.

  17. Effects of Different Storage Temperatures on Quality of Fresh-cut Yam%不同贮藏温度对鲜切山药品质的影响

    Institute of Scientific and Technical Information of China (English)

    赵梅

    2012-01-01

    In order to study the effects of different storage temperature on quality of fresh-cut yam, Chinese yam was used as raw material. The fresh-cut yam was put at 0℃, 4℃, 6℃, l0℃ and room temperature. The factors that were weight loss rate, cell membrane permeability, browning index, and PPO activity were measured. The results showed that: low temperature (0-4℃) could inhibit water evaporation and reduce weight loss rate, delay cell membrane permeability increase and reduce the rate of cell membrane permeability, inhibit enzymatic browning and reduce browning degree, maintain low PPO activity. The quality of fresh-cut yam was maintained. 0 to 4℃ was safe and suitable for preserving fresh-cut yam.%以山药为原料,研究了不同贮藏温度对鲜切山药品质的影响.将鲜切山药分别置于0、4、6、10℃和室温,测定鲜切山药失重率、细胞膜渗透率、褐变度和多酚氧化酶活性(PPO)各项指标的变化.结果表明:与室温相比,0~4℃的低温贮藏能抑制水分蒸发从而有效降低鲜切山药失重率,延缓鲜切山药细胞膜透性上升,降低细胞膜渗透率,显著抑制了酶促褐变,大大降低了褐变度,维持较低的多酚氧化酶活性,较好地保持鲜切山药的品质.0~4℃是鲜切山药适宜的贮藏温度.

  18. Effect of Chitosan Coating on the Quality of Fresh-cut Pumpkin(Cucurbita Moschata) during Storage%壳聚糖涂膜对鲜切南瓜贮藏品质的影响

    Institute of Scientific and Technical Information of China (English)

    张丹丹; 杨绍兰; 吴昊; 张宏斌; 王成荣

    2012-01-01

    Fresh "MiBen" pumpkins were subjected to coating with chitosan at different concentrations (0.5%, 1.0%, 1.5%)and subsequent storage at 4 ℃ in order to examine the fresh-keeping effect of chitosan coating on fresh-cut pumpkin. During the storage, changes in polysaccharose, carotenoid and total phenol contents, ethylene production, weight loss rate, firmness and the activity of PAL and POD of fresh-cut pumpkin were measured. Results showed that chitosan coating could delay the reductions of firmness, polysaccharose, carotenoid and total phenol contents, and also could delay the increase of ethylene production, obviously enhance PAL and POD activities, reduce weight loss rate, and substantially extend the shelf life of fresh-cut pumpkin, especially at a concentration of 1.0%.%以新鲜的“蜜本”南瓜(Cucurbita moschata)为试验材料,探讨不同质量分数(0.5%、1.0%、1.5%)壳聚糖涂膜液处理对鲜切南瓜贮藏品质的影响.结果表明:采用壳聚糖涂膜液处理,不同程度地延缓了鲜切南瓜乙烯释放量的增加和硬度的下降,阻止了多糖和类胡萝卜素的减少,抑制了POD、PAL酶活性的下降和总酚含量的降低.其中以质量分数为1.0%壳聚糖涂膜液处理的效果最好,有效地保持了鲜切南瓜贮藏期间的品质.

  19. Research on application of two kinds of natural food preservatives on fresh cut vegetables preservations%2种天然食品防腐剂在鲜切蔬菜保鲜中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李晶莹; 王筠婷; 葛婷; 孙雨宏; 丁敬争; 任建军

    2015-01-01

    This paper introduces chitosan and tea polyphenols as raw material to study the effect of these two kinds of natural food preservatives on fresh cut green peppers and cucumbers storage quality. In addition, the different effects with various concentrations of chitosan and tea polyphenol as coating preservation of fresh cut green peppers and cucumbers were compared. The conclusion is as follows: 1% of Chitosan and 2% of tea polyphenol play significant role in food preservation to fresh cut green peppers and cucumber.%壳聚糖和茶多酚作为一种安全、无毒、有效的涂膜保鲜剂,近年来被广泛地研究和应用.分别以壳聚糖和茶多酚为材料,研究它们对鲜切青椒和黄瓜贮藏品质的影响,并比较了不同浓度的壳聚糖及茶多酚涂膜保鲜鲜切青椒和黄瓜的效果.试验结果表明,1%的壳聚糖、2%的茶多酚在一定的环境条件下对鲜切青椒和黄瓜贮藏具有良好的保鲜效果.

  20. Effects of Hypobaric Cold Storage Technology on Preservation of Fresh-cut Fruits and Vegetables%减压冷藏技术对鲜切果蔬保鲜效果的研究

    Institute of Scientific and Technical Information of China (English)

    胡欣; 张长峰; 郑先章

    2012-01-01

    以花王菜等6种蔬菜和苹果为试材,研究减压冷藏技术对鲜切果蔬的保鲜效果.结果表明,减压冷藏处理技术是可应用于鲜切果蔬保鲜的新技术.将果蔬原材料经减压冷藏处理(压力范围为600~3 200 Pa),再清洗切割加工成鲜切产品,可比普通冷藏有效减缓山药、土豆和苹果等鲜切产品的褐变;明显减少鲜切花王菜、鸡毛菜和空心菜的萎蔫、黄叶与腐烂,保持鲜切绿叶菜的新鲜品质;切割前的减压冷藏结合真空预冷,可大大减轻鲜切西兰花的黄化、萎蔫、花粒变大、脱落及切面的褐变与腐烂,显著延长鲜切果蔬的冷藏货架期及冷链断链保鲜期.%The experiments used 6 kinds of vegetables and apple as material to research the preservation effects by using hypobaric cold storage technology. The results indicated that, the hypobaric cold storage treatment technology was an advanced new technology of preservation and process for fresh-cut vegetables and fruits. The raw materials of fruits and vegetables were treated by hypobaric cold storage, pressure 600-3 200 Pa, followed washing and cutting to fresh-cut products. Compared with normal cold storage, the hypobaric cold storage treatment technology could retard the brown degree of cut face of yam, potato and apple, decrease the wilting, yellow leaf and rotting of Huawang vegetable, Jimao vegetable and swamp cabbage, also kept their good fresh quality. Hypobaric cold storage before cutting combined with vaccum pre -cooling treatment could greatly readuce the yellow changed, wilting, flower grain growing and dropping, brown degree of cut face and rotting of broccoli, and prolong the shelf life of fresh-cut fruits and vegetables and preservation period of cold chain scission.

  1. Vida útil de produto minimamente processado composto por abóbora, cenoura, chuchu e mandioquinha-salsa Shelf life of fresh-cut composed of vegetables

    Directory of Open Access Journals (Sweden)

    Juliana Alvarenga Alves

    2010-02-01

    Full Text Available Objetivou-se avaliar o efeito do tempo de armazenamento sobre a qualidade de produto minimamente processado à base de hortaliças: abóbora (Cucurbita moschata Duch, cenoura (Daucus carota L., chuchu (Sechium edule Swartz e mandioquinha-salsa (Arracacia xanthorrhiza Bancroft. As hortaliças foram sanificadas em hipoclorito de sódio 200 mg.L-1, por 5 minutos, descascadas, manualmente, e cortadas utilizando-se processador. O produto processado foi sanificado em hipoclorito de sódio 50 mg.L-1, por 3 minutos, e apenas as mandioquinhas-salsa foram imersas em solução de ácido ascórbico 1%, por 2 minutos. As embalagens flexíveis de polietileno de baixa densidade linear (25 x 20 cm, contendo 400 g do "mix", foram armazenadas a 5ºC e 99% UR, por 8 dias. A firmeza e o valor L* das hortaliças estudadas não alteraram com o tempo de armazenamento. Os valores a* e b* da abóbora não oscilaram durante o armazenamento. O valor a* da mandioquinha-salsa e do chuchu aumentou e o da cenoura diminuiu com o armazenamento, enquanto o valor b* da cenoura, do chuchu e da mandioquinha-salsa reduziu. O "mix" apresentou taxa de perda de massa muito baixa e ascensão respiratória até o oitavo dia. A atmosfera de equilíbrio, em torno de 2,93% de O2 e 7,06% de CO2, foi alcançada no interior da embalagem, contendo o "mix", a partir do segundo dia. Não foi detectada a presença de coliformes a 45ºC e Salmonella sp. em nenhuma amostra. Os coliformes a 35ºC aumentaram durante o armazenamento. Conclui-se que, o produto minimamente processado, à base de hortaliças mantém a sua qualidade por 8 dias a 5ºC.The objective of this work was to evaluate the effect of storage time on the quality of fresh-cut product made up of four vegetables: pumpkin (Cucurbita moschata Duch, carrot (Daucus carota L., chayote (Sechium edule Swartz, and peruvian carrot (Arracaia xanthorrhiza Bancroft. The vegetables were sanitized in sodium hypochlorite solution (200 mg.L-1 for 5

  2. 食前热水处理提高鲜切黄瓜微生物安全性的研究%Improving microbial safety and quality of fresh-cut cucumbers by hot water treatments just before eating

    Institute of Scientific and Technical Information of China (English)

    张甜甜; 李天琪; 王庆国; 王敏

    2013-01-01

    This paper aimed to study the effect of hot water treatment for killing foodborne pathogens on freshcut cucumber while maintaining its freshness.Based on the sensory quality of fresh-cut cucumber after hot water treatment,selected hot water treatment conditions,and further studies of hot water treatment in reducing foodborne pathogens in water and on surface of fresh-cut cucumber were carried out.The results showed that:the high initial concentration numbers of 5.42 and 5.16log CFU/g for Salmonella Typhimurium and Listeria monocytogenes respectively on fresh-cut cucumbers treated by 60℃ 5min heat treatment,were reduced to under detection line,although fresh-cut cucumber antioxidant value reduced and cell membrane permeability increased,but the measured hardness did not change,maintaining fresh sensory and good eating value.%探讨食前热水处理能否有效杀灭鲜切黄瓜表面的单增李斯特菌和鼠伤寒沙门氏菌这两种食源性致病菌,同时又保持其新鲜度.实验首先根据热水处理后鲜切黄瓜的感官品质,筛选了其耐热条件,进一步研究了热处理对水中和鲜切黄瓜表面食源性致病菌降低的效果.结果表明,经60℃5min热水处理,鲜切黄瓜上的鼠伤寒沙门氏菌、单增李斯特菌数量从高起始染菌浓度5.42、5.161og CFU/g,降低到检测线(0.6log CFU/g)以下,鲜切黄瓜的抗氧化值降低、细胞膜透性有所提高,但其测定硬度变化不大,感官上仍鲜脆,仍具有较好食用价值.

  3. Effects of Rhodotorula sp on the Physiological Metabolism of Fresh-cut Apples%红酵母菌对鲜切苹果生理代谢的影响

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

      将从富士苹果皮中分离出的红酵母菌配制成不同浓度(105、106、107 CFU/mL)的菌悬液处理鲜切苹果,研究红酵母菌对鲜切苹果在10℃条件下贮藏10 d期间可溶性蛋白含量及相关酶活性的影响。结果表明,红酵母菌能够延迟鲜切苹果可溶性蛋白含量出现最大值的时间,有助于维持细胞的正常代谢。另外,红酵母菌能够抑制过氧化物酶(POD)、多酚氧化酶(PPO)活性和丙二醛(MDA)含量的上升,可有效控制鲜切苹果细胞膜的过氧化作用,延缓苹果的氧化和组织的衰老。但在贮藏前期,红酵母菌也激活了鲜切苹果的多聚半乳糖醛酸酶(PG)活性,加速了苹果的软化。%Fresh-cut apples were treated with different concentrations of Rhodotorula sp (105, 106, 107 CFU/mL) which separated from fresh-cut Fuji apple peel. This article studied the effects of Rhodotorula sp on the soluble protein content and activities of related enzymes of fresh-cut apples during 10 days storage at 10 ℃. The results showed that, Rhodotorula sp could delay the time of the maximum of soluble protein content, and could help to maintain the normal metabolism of cell. In addition, Rhodotorula sp could inhibit the increase of POD and PPO activities and MDA content, effectively control the peroxidation of cell film of fresh-cut apple, and delay oxidation of apple and senescence of tissue. But in the early storage, Rhodotorula sp also activated polygalacturonase (PG) activity, and accelerated the softening of fresh-cut apple.

  4. 不同甜瓜品种鲜切加工特性评价%Suitability of Different Melon Cultivars for Fresh-Cut Processing

    Institute of Scientific and Technical Information of China (English)

    王丽; 张学杰; 李慧; 王怀松

    2012-01-01

    Hardness, soluble solid content (SSC), sensory quality, VC content, and marketable fruit percentage were measured on melon fruits from four different cultivars, reticulate melon (Zhongmi No. 55 and Huami No. 2) and smooth rind melon (Zhongmi No. 116 and Yujinxiang) at days 0, 14 and 28 of post-harvest storage at 10 ℃. Meanwhile, grey correlation analysis was used to evaluate the experimental data. The suitability of the melon cultivars for fresh-cut processing followed the decreasing order of Huami No. 2 〉 Zhongmi No. 55 〉 Zhongmi No. 116 〉 Yujinxiang. Huami No. 2 was characterized by higher marketable fruit percentage at the early harvest stage, better sensory quality and higher VC content, and Zhongmi No. 55 showed the characteristics of higher marketable fruit percentage and better sensory quality and storage tolerance.%以网纹(中蜜55号、华蜜2号)、光皮(中蜜116、玉金香)两个类型甜瓜共4个品种为实验材料,分别测定其产量及采收后贮藏(10℃)0、14、28d时的硬度、可溶性固形物含量、感官品质、VC含量及出品率,实验结果采用灰色关联度分析方法进行综合评价。结果表明:供试甜瓜品种用于鲜切加工的优先排序依次为华蜜2号、中蜜55号、中蜜116和玉金香,其中华蜜2号在采摘初期表现出产量高、感官品质好、VC含量高的特点,中蜜55号呈现出产量高、品质较好、耐贮性好的特征。

  5. Effects of crude protein level in concentrate supplements on animal performance and nitrogen utilization of lactating dairy cows fed fresh-cut perennial grass.

    Science.gov (United States)

    Hynes, D N; Stergiadis, S; Gordon, A; Yan, T

    2016-10-01

    Nitrogen pollution of air and ground water from grazing cattle is of increasing concern. Although several studies have investigated mitigation strategies for nitrogen output from dairy cows fed conserved forages and concentrates, similar research on fresh-cut grass in addition to production parameters is limited. The current study, using 3dietary treatments and incorporating 2 genotypes, was designed to evaluate the effects of concentrate crude protein (CP) levels on animal production and nitrogen utilization efficiency (NUE) in lactating dairy cows. Twelve multiparous cows (6 Holstein and 6 Holstein × Swedish Red) were used in a changeover study with three 25-d periods and 3 diet treatments. Low, medium and high CP concentrate [14.1, 16.1, and 18.1%, respectively, dry matter (DM) basis] diets were fed at 32.8% DM intake combined with good-quality zero-grazed perennial ryegrass (18.2% CP, DM basis). Each period consisted of an adaptation phase (18d) housed as a single group, a 1-d adaptation phase in individual stalls, and a 6-d measurement phase with feed intake and feces, urine, and milk output recorded. We observed no significant interaction between cow genotype and concentrate CP level on any animal performance or NUE parameter. Total DM intake, milk yield and composition, and NUE were not affected by dietary treatment. However, increasing concentrate CP level increased (1) N intake by 42g/d and excretion in urine and manure by 38 and 40g/d, respectively, and (2) the ratio of urine N over manure N. Feeding high CP rather than low CP concentrate increased milk urea N (MUN) content by 3.6mg/dL and total MUN output by 1.08g/d. Crossbred cows had lower grass DM intake, total DM intake, total N intake, and energy-corrected milk yield. However, cow genotype had no significant effect on NUE or MUN parameters. Equations have been developed to predict urine N excretion using MUN output as a sole predictor or in combination with dietary CP level. The present study

  6. Fresh-Keeping Effect of Different Films on Fresh-Cut Pumpkin during Storage at Low Temperature%不同保鲜膜处理对低温贮藏下鲜切南瓜保鲜效果的影响

    Institute of Scientific and Technical Information of China (English)

    张丹丹; 杨绍兰; 吴昊; 张宏斌; 王成荣

    2012-01-01

    The present study aimed to evaluate the fresh-keeping effect of two types of edible multi-purpose preservative films(prepared mainly with chotisan and sodium alginate in the presence and absence of clove oil) on fresh-cut ‘Miben’ pumpkin.Fresh-cut ‘Miben’ pumpkin was coated with different films,and then stored at low temperature.Textural properties,ethylene production,and MDA content in fresh-cut pumpkin were determined during storage period.The results indicate that the two types of edible preservative films could obviously maintain textural properties,reduce MDA accumulation,and delay ethylene production in fresh-cut pumpkin.The edible film consisting of chotisan,sodium alginate and clove oil was more effective in maintain storage quality of fresh-cut pumpkin and prolonging its shelf-life.%以新鲜的"蜜本"南瓜为试验材料,研究可食性多功能防腐保鲜膜对鲜切南瓜的保鲜效果。将经切割后的南瓜用不同保鲜膜包裹处理,测定其硬度、弹性、咀嚼性、黏性、乙烯释放速率、丙二醛(MDA)的变化,探讨不同保鲜膜处理对鲜切南瓜的质地和生理生化代谢的影响。结果表明:不同保鲜膜处理能不同程度地保持鲜切南瓜的质地,延缓乙烯释放量的增加,减小MDA积累;其中,2号保鲜膜(主成分为壳聚糖、海藻酸钠、丁香油等)处理效果最好,有效地提高了鲜切南瓜贮藏期间的品质,并延长了其货架期。

  7. Mangas minimamente processadas amadurecidas naturalmente ou com etileno e armazenadas em diferentes embalagens Fresh cut mangos ripped naturaly or induced by ethylene and stored in different packges

    Directory of Open Access Journals (Sweden)

    Bianca Sarzi de Souza

    2006-08-01

    Full Text Available Avaliaram-se produtos minimamente processados de mangas 'Tommy Atkins' amadurecidas naturalmente ou com etileno. Os frutos amadurecidos com aplicação de etileno foram colhidos no estádio "meio-maturo" (de vez e tratados com etileno (1g.L-1 e mantidos em câmaras, por 12 horas, a 23-25ºC e 85-90% UR. Os frutos foram selecionados, lavados com detergente, sanitizados (200mg.L-1 de cloro e armazenados por 12 horas, a 10ºC. Após este período, foram processados sob condições assépticas, a 12ºC, acondicionados em embalagem PET ou bandeja de poliestireno expandido recoberta por filme de PVC e armazenados a 3ºC. Foram avaliados, a cada 3 dias, a resistência e a coloração da polpa, os teores de ácido ascórbico, sólidos solúveis (SS, acidez titulável (AT, carboidratos solúveis, redutores e amido, relação SS/AT, pH e atividade da peroxidase. Durante o período de armazenamento, os pedaços de manga tornaram-se mais firmes e mantiveram-se amarelos, porém mais escurecidos, o que foi indicado por redução na luminosidade. Os teores de ácido ascórbico nos pedaços das mangas amadurecidas com etileno apresentaram-se menores que os das amadurecidas naturalmente. A acidez apresentou tendência de redução durante o armazenamento, com as amadurecidas com etileno apresentando os maiores valores e os menores pH. Os produtos de mangas amadurecidas com etileno apresentaram os maiores valores de SS, mas menor relação SS/AT, indicando gosto mais azedo. Os teores de carboidratos solúveis e de amido não apresentaram variação com tendência definida, mas os de carboidratos redutores apresentaram tendência de acréscimo, e a atividade da peroxidase, de decréscimo durante o armazenamento. Os produtos de mangas amadurecidas naturalmente foram superiores aos amadurecidos com etileno, mantendo boa qualidade e aparência adequada para a comercialização até o 13º dia, enquanto os das amadurecidas com etileno, por 11 dias.Fresh cut 'Tommy

  8. Application of preservation technologies in fresh-cut fruits and vegetables%应用于鲜切果蔬中的保鲜技术研究进展

    Institute of Scientific and Technical Information of China (English)

    纪懿芳; 胡文忠; 姜爱丽

    2015-01-01

    Fresh-cut fruits and vegetables are increasingly favored by consumers, their sales increased by their convenience, rich nutrition and great freshness characteristics. Fresh-cut fruits and vegetables are also known as cut fruits and vegetables, semi processed fruits and vegetables, fruits and vegetables such as conditioning, usually refer to change vegetables, fruit, and physical shape, but still continue in its state of fresh fruit products or produce mixed products. The production process generally goes through cleaning, grading, trimming, segmentation, washing, drying, packaging, storage and distribution, available to consumers directly edible or by restaurants cooking. Preservation technologies in fresh-cut fruits and vegetables significantly affect sensory aspects such as color, smell, texture, flavor, and tissue. This paper summarized the preservation technologies of fresh-cut fruits and vegetables, such as physical, chemical, biological and combinatorial preservation technologies for fresh-cut fruits and vegetables, which would provide the further understanding of current problems and guidance of future research directions, and prospect for future developments presented.%鲜切果蔬因其方便、健康、新鲜等特点日益受到人们的青睐,销售量逐年增加。鲜切果蔬又称为切割果蔬、半加工果蔬、调理果蔬等,通常是指改变了蔬菜、水果物理形状、但仍然保持其新鲜状态的果蔬制品或果蔬混合产品。其生产过程一般要经过清洗、分级、修整、切分、洗涤、干燥、包装、贮存、配送等工序,可供消费者直接食用或餐饮业使用。鲜切果蔬保鲜技术对果蔬的色泽、气味、质地、营养成分、组织状态等感官方面得以最大的保留,减少果蔬因经过清洗、去皮、等机械处理过程导致的品质改变。本论文主要对现阶段鲜切果蔬的保鲜技术研究进展进行综述,其主要技术包括物理、化学和综

  9. Effects of Different Pretreatments on Micorganism of Fresh-cut Ananas comosus%预处理方法对鲜切菠萝微生物的影响

    Institute of Scientific and Technical Information of China (English)

    邵远志; 李雪萍; 贾文君; 李雯

    2011-01-01

    为保持和改善鲜切菠萝的贮藏品质,以‘巴厘’菠萝为试材,研究不同预处理方法(对照,有机酸,漂烫和有机酸+漂烫)对鲜切菠萝微生物的影响.结果表明:各处理的大肠菌群发生较少且总数极低;在对霉菌的影响上,漂烫处理的抑制效果最明显,至贮藏末期,其霉菌总数仅为CK的1/10,其次是综合处理;鲜切菠萝的酵母菌含量随着贮藏时间的延长不断增多,对照处理上升最快,其次是有机酸处理,而漂烫处理和综合处理的增加缓慢,至贮藏末期(11天),分别比对照低1.7× 106 cfu/g和1.5×106 cfu/g,处理间差异极显著(P<0.01);鲜切菠萝的菌落总数不断增加,对照处理上升最快,其次是有机酸处理,漂烫处理的增加最慢.说明霉菌、酵母菌是鲜切菠萝的主要微生物,漂烫处理能够较显著地抑制鲜切菠萝霉菌、酵母菌和菌落总数的上升,防止果实腐烂变质,而对照和单独酸处理在鲜切菠萝品质保持方面的效果较差.%In order to maintain and improve the storage quality of fresh-cut Ananas comosus, Ananas comosus 'Bali' was used to investigate the effects of different pretreatments (control, organic acid, blanching and organic acid combined with blanching) on micorganism during storage. The results showed that there were fewer and lower number of coliform bacteria in storage of fresh-cut pineapple; for the impact of mold, the effect of blanching was the most obvious, the number of fungus was only 1/.10 of control when the day 5, followed by the integrated treatment. With the extension of storage time, the yeast content of fresh-cut pineapple increased, the yeast increasing of control treatment was the fastest, followed by organic acid treatment, while, the yeast increasing of blanching and integrated treatments were most slowly, at the end of storage (11 d), the yeast contents of blanching and integrated treatments were lower 1.7xl06cfu/g and 1.5xl06cfu/g than the

  10. Preparation of pre-cut corneas from fresh donated whole globes for Descemet's stripping automated keratoplasty: 3-year results at the Central Eye Bank of Iran.

    Science.gov (United States)

    Kanavi, Mozhgan Rezaei; Javadi, Mohammad Ali; Javadi, Fatemeh; Chamani, Tahereh

    2014-09-01

    To describe the technique and the results of the preparation of pre-cut corneas for Descemet's stripping automated endothelial keratoplasty (DSAEK) during a 3-year period at the Central Eye Bank of Iran (CEBI). The method of preparation of pre-cut corneas from donated whole globes at the CEBI is described and the frequency and percentage of pre-cut corneas prepared for DSAEK, between April 2009 and March 2012, are specified. Moreover, post-operative reports are reviewed for any complaints about using pre-cut tissues for DSAEK. Out of the 1,518 donated whole globes appropriate for DSAEK, 1,478 (97.4 %) pre-cut corneas were successfully prepared. The method of preparation failed in 40 (2.6 %) cases. Based on the eye bank post-operative reports, thickness of pre-cut tissues for DSAEK was deemed unacceptable in only 6 (0.4 %) cases prior to surgery; five of these were too thick and one was too thin. Preparation of pre-cut corneas, for DSAEK from donated whole globes, in the CEBI is a safe and easy method, with very good preservation of endothelial cells after the preparation of the pre-cut corneas and reduced risks from corneal manipulation.

  11. The Effect of Short-term Storage and the Hot Water Treatment of Fresh-Cut Pepper Fruit cv. ‛Blondy F1’ and ‛Yecla F1’ on the Content of Bioactive Compounds and Antioxidant Properties

    National Research Council Canada - National Science Library

    Justyna I. Szwejda-Grzybowska; Ryszard Kosson; Maria Grzegorzewska

    2016-01-01

    The aim of the experiment was to determine the changes in the contents of bioactive compounds and antioxidant/antiradical activity in fresh-cut fruits of sweet pepper cv. ‘Blondy F ’ and ‘Yecla F...

  12. 贮藏温度对鲜切香菜营养成分和抗氧化活性的影响%Effects of storage temperature on nutritional compositions and antioxidant activity of fresh-cut coriander

    Institute of Scientific and Technical Information of China (English)

    韩聪; 李晓安; 高梵; 金鹏; 郑永华

    2015-01-01

    Objective To analyze the effect of different storage temperature on the nutritional compositions and antioxidant activity of fresh-cut coriander.Methods Fresh-cut coriander was cut and placed into preservation boxes, and stored at 4℃ , 10℃ and 20℃ . The changes of ascorbic acid, chlorophyll, soluble sugar, total phenolics, total flavonoids and DPPH radical scavenging activity were investigated.ResultsThe results indicated that cutting induced a fast loss of ascorbic acid, chlorophyll and soluble sugar. Compared with 10℃ and 20℃ , storage temperature of 4℃ significantly decreased the disruption of these nutrients. In addition, cutting also induced the synthesis and accumulation of phenolic and flavone compounds, enhanced its DPPH radical scavenging activity, and improved the antioxidant activity of coriander. Compared with 4℃ and 10℃ , the content of phenolic and flavone compounds and antioxidant activity in fresh-cut coriander were higher at 20℃ .Conclusion Low storage temperature can preserve the nutritional quality of fresh-cut coriander, while higher temperature can induce the improvement of antioxidant activity of fresh-cut coriander.%目的:分析不同温度贮藏对鲜切香菜营养成分和抗氧化活性的影响。方法将香菜进行切割处理后装入保鲜盒,在4℃、10℃和20℃下贮藏,测定鲜切香菜抗坏血酸、叶绿素、可溶性糖、总酚、总黄酮含量和DPPH自由基清除率的变化。结果切割伤害会促进香菜抗坏血酸、叶绿素和可溶性糖含量迅速下降,与10℃和20℃相比,4℃低温贮藏的香菜抗坏血酸等营养成分的消耗速率最低。此外,切割还会诱导香菜多酚和类黄酮类物质的合成、积累及DPPH自由基清除率的上升,从而增强其抗氧化活性。与4℃和10℃相比,20℃条件下香菜的多酚类和类黄酮类物质积累最多,抗氧化活性最强。结论低温贮藏有利于维持鲜切香菜的营养成分,而高温贮藏会

  13. Volatile compounds profile of fresh-cut peki fruit stored under different temperatures Perfil dos compostos voláteis do pequi minimamente processado armazenado sob diferentes temperaturas

    Directory of Open Access Journals (Sweden)

    Clarissa Damiani

    2009-06-01

    Full Text Available The objective of this work was to identify and verify the influence of time and temperature on the volatile compounds profile of fresh cut peki. Peki fruits were washed, sanitized, their kernels were extracted, and they were packaged and stored for 15 days at 0, 5, and 10 °C and 6 days at 22 °C. The volatiles compounds were analyzed by GC - MS. Ethyl hexanoate and ethyl octanoate were found in higher percentages, 63 and 16.3%, respectively. The determined volatiles were not influenced by the storage period. Hexanoic acid, ethyl 2-octenoate and ethyl decanoate were not influenced by the different temperatures. The temperatures 0, 5, and 10 °C did not influence ethyl hexanoate, ethyl 2-hexenoate and ethyl octanoate either. In addition, the temperatures 5, 10, and 22 °C did not influence ethyl hexanoate, cis-β-ocimene and ethyl octanoate. The temperature of 22 °C determined higher percentages of ethyl hexanoate and lower percentages of ethyl octanoate, in comparison to the temperature of 0 °C, and higher percentages of ethyl 2-hexenoate in comparison to the temperatures of 0, 5, and 10 °C. The temperature of 5 °C determined higher percentage of cis-β-ocimene when compared with the temperature of 0 °C. The storage temperatures of 0 and 5 °C were the most appropriate for the conservation.O objetivo do trabalho foi identificar e verificar a influência do tempo e da temperatura sobre o perfil dos compostos voláteis de pequi minimamente processado. O pequi foi lavado, sanificado, seus pirênios extraídos, embalados e armazenados por 15 dias a 0, 5 e 10 °C e 6 dias a 22 °C. Os compostos voláteis foram analisados por CG-EM. Hexanoato de etila e octanoato de etila foram encontrados em porcentagens mais altas, 63 e 16.3% respectivamente. Os voláteis determinados não foram influenciados pelo tempo de armazenamento. Ácido hexanóico, 2-octenoato de etila e decanoato de etila não foram influenciados pelas diferentes temperaturas. As

  14. 壳聚糖涂膜对鲜切菠萝蜜的保鲜作用%Study on Preservation of Fresh-cut Jackfruit by Chitosan Film

    Institute of Scientific and Technical Information of China (English)

    姜秋焕; 叶盛权; 叶春海; 吕庆芳; 韩锐

    2012-01-01

    本文通过壳聚糖对鲜切菠萝蜜进行涂膜处理,研究保质期内还原糖含量、总酸含量、水分含量的变化,分析壳聚糖涂膜对干苞和湿苞菠萝蜜的保鲜效果.结果表明:在3±1℃的条件下贮藏15 d,涂膜鲜切菠萝蜜的还原糖的变化速率较小,均小于未处理组.涂膜湿苞和干苞的还原糖含量分别降低了3.58%和3.81%,而未处理组还原糖含量降低了4.77%.贮藏到第6d时,涂膜处理的湿苞和干苞含水量都达到最低值,对照组的含水量为65.96%,湿苞和干苞的含水量分别为72.60%和73.81%,总酸量分别降低了0.13%和0.15%,未处理组总酸含量降低了0.23%.壳聚糖涂膜处理能够延缓菠萝蜜的后熟,对湿苞的保鲜效果优于对干苞的保鲜效果.%The effect of chitosan film on the preservation of fresh-cut jackfruit was studied. The change of reducing sugar content, total sugar content and water content was studied, and the effect of chitosan film on the preservation of dry and wet jackfruit was analyzed. It illustrated that the variation of reducing sugar treated jackfruit was less than that of untreated ones under the condition of storage at 3±1 °C for 15 days. Reducing sugar contents of wet and dry decreased by 3.58% and 3.81%, respectively, while that of uncoated group reduced by 4.77%. Water content of wet and dry jackfruit coated was lowest in the sixth day. Water content of uncoated group was 65.96%, and that of wet and dry jackfruit was respectively 72.06% and 73.81 %. And total acid content of these respectively decreased by 0.13% and 0.15%. Total acid content of uncoated group was reduced by 0.23%. Chitosan coating could delay the ripening of jackfruit, and the preservation of wet jackfruit coated with chitosan was better than that of dry jackfruit.

  15. Active packaging for fresh-cut iceberg lettuce (Lactuca sativa L. / Embalagem ativa para alface americana (Lactuca sativa L. minimamente processada

    Directory of Open Access Journals (Sweden)

    Fábio Yamashita

    2010-09-01

    Full Text Available The minimal processing of horticultural products endears the raw material and is convenient to the consumer due to the facility for preparing and consuming. The objective of this work was to develop an active packaging for fresh-cut iceberg lettuce (Lactuca sativa L. to increase its shelf life. Minimally processing methodology was defined and the product quality was determined by sensorial, physico-chemical and microbiological analysis. The lettuce tree was selected, trimmed, pre-washed, soaked in sanitized water (100ppm of active chlorine for 15 minutes and centrifuged. The lettuce leafs were packed in polypropylene pots with a sachet containing 1-methylcyclopropene (1-MCP and sealed with biodegradable starch film. Soon after the processing, the product was stored at 4oC for 12 days. Periodically samples were evaluated in terms of appearance and purchase intention, soluble solids and vitamin C contents, pH, texture, color, weight loss and total count of mesophilic and psicotrofic microorganisms, lactic bacteria, mould and yeast. Using 1-MCP in sachet format did not increase the lettuce shelf life but the minimal processing combined with packaging sealed with biodegradable film is practicable as the product showed good sensorial acceptance, low microbiological counts and shelf life of 5 days at 4oC.O processamento mínimo de produtos hortícolas agrega valor à matéria-prima e são convenientes ao consumidor, devido à facilidade de preparo e consumo. O objetivo do trabalho foi desenvolver uma embalagem ativa para alface americana (Lactuca sativa L. minimamente processada visando o aumento da vida útil. Foi definida uma metodologia de processamento mínimo e a qualidade do produto foi acompanhada através de avaliação sensorial, físico-química e microbiológica. As cabeças de alface foram desfolhadas, selecionadas, pré-lavadas, sanificadas (100 ppm de cloro ativo por 15 minutos e centrifugadas. As folhas foram acondicionadas em potes de

  16. Application of edible active films coatings on preservation of fresh-cut fruits and vegetables%可食性活性涂膜在鲜切果蔬保鲜中的应用

    Institute of Scientific and Technical Information of China (English)

    萨仁高娃; 胡文忠; 修志龙; 姜爱丽; 冯可

    2015-01-01

    可食性涂膜是一种由天然可食性材料制成的选择透过性薄膜,具有调节果蔬内部气体交换、减少水分损失、降低腐烂率及延长货架期的特性,在果蔬包装及保鲜领域中已引起广泛关注。鲜切果蔬具有新鲜、方便、快捷等特点,已在全球范围内广泛供应餐饮业及零售业。可食性涂膜作为多种食品添加剂的载体常应用于生鲜产品中,且将活性添加剂与可食性涂膜结合可以延长鲜切果蔬的货架期,提高果蔬品质,减少果蔬表面致腐及致病菌增长的风险。可食性活性涂膜将作为一种绿色、安全、营养的保鲜技术,并将应用于鲜切果蔬保鲜领域的研究。本文综述了可食性涂膜的分类及其添加的抗菌剂、抗氧化剂、塑形剂、营养素等活性成分在鲜切果蔬保鲜中的应用,旨在开发用于鲜切果蔬保鲜的功能性可食性涂膜。%Edible film is a kind of selectively permeable membrane which is made of natural edible material. It can coordinate the gas exchange, reduce the water loss and the rot rate, and prolong the shelf-life of fruits and vegetables. Edible coating film has gained a wide concern in the fields of food package and food storage. Fresh-cut fruits and vegetables had the characters of fresh, convenient, and rapid, which were widely applied in catering industry and retail industry. Edible coating as carrier of food adding agent were applied in fresh products. It incorporated with active adding agent that would prolong the shelf life, improve quality of fresh-cut fruits and vegetables, and reduce the increasing of pathogenic bacteria. Edible coating had been applied to preservation for fresh-cut fruits and vegetables as a kind of preservation technology of food safety. The application of edible coating classification and adding active ingredient of antimicrobial, antioxidant, nutrient on fresh-cut fruits and vegetables was reviewed in this paper. The

  17. Integration of antimicrobial pectin-based edible coating and active modified atmosphere packaging to preserve the quality and microbial safety of fresh-cut persimmon (Diospyros kaki Thunb. cv. Rojo Brillante).

    Science.gov (United States)

    Sanchís, Elena; Ghidelli, Christian; Sheth, Chirag C; Mateos, Milagros; Palou, Lluís; Pérez-Gago, María B

    2017-01-01

    The greatest hurdle to the commercial marketing of fresh-cut fruits is related to their higher susceptibility to enzymatic browning, tissue softening, and microbial growth. The aim of this study was to test the efficacy of a pectin-based edible coating and low oxygen modified atmosphere packaging (MAP) to control enzymatic browning and reduce microbial growth of fresh-cut 'Rojo Brillante' persimmon. The survival of Escherichia coli, Salmonella enteritidis and Listeria monocytogenes artificially inoculated on fresh-cut fruit was also assessed. The pectin coating was amended with 500 IU mL(-1) nisin (NI) as antimicrobial agent and 10 g kg(-1) citric acid and 10 g kg(-1) calcium chloride as anti-browning and firming agents, respectively. Persimmon slices were dipped in the coating or in water (control) and packed under 5 kPa O2 (MAP) or in ambient atmosphere for up to 9 days at 5 °C. Microbial growth, package gas composition, colour, firmness, polyphenol oxidase activity, visual quality and overall sensory flavour of persimmon slices were measured during storage. Coating application combined with active MAP significantly reduced the CO2 emission and O2 consumption in the package. The coating was effective in reducing browning and also inhibited the growth of mesophilic aerobic bacteria. Coating also reduced the populations of E. coli, S. enteritidis and L. monocytogenes. The combination of the pectin-based edible coating and active MAP proved to be the most effective treatment to maintain the sensory and microbiological quality of persimmon slices for more than 9 days of storage. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  18. Effects of different washing agents on the preservation of fresh-cut lettuce%清洗方式对鲜切生菜保鲜效果的影响

    Institute of Scientific and Technical Information of China (English)

    林永艳; 谢晶; 朱军伟; 罗爱琼

    2012-01-01

    Static electricity, ozone, sodium hypochlorite, brine electrolysis and tap-water were used to clean the fresh-cut lettuce, and the quality changes during storage were studied. It was shown that five kinds of washing agents had little effect on the weight loss rate of fresh-cut lettuce. Ozone, sodium hypochlorite, brine electrolysis treatment can delay the decrease of Vc , chlorophyll content in fresh-cut lettuce significantly, and maintaining good sensory quality in the preservation. In the above five kinds of washing agents, ozone treatment was the best method, and it keeps commodity value of lettuce at the 12lh days.%以静电水、臭氧水、次氯酸钠水、电解水、自来水对生菜切割后进行处理,研究不同处理方式对贮藏过程中其品质变化的影响.结果表明,这5种处理方式对鲜切生菜失重率的影响不大;臭氧水、次氯酸钠水、电解水处理能够显著延缓鲜切生菜VC、叶绿素含量的下降,在贮藏过程中保持了较好的感官品质.在上述5种处理方式中臭氧水对后期的保鲜效果最佳,是切割蔬菜贮藏前推荐的处理方式,鲜切菜产品贮藏到第12天仍有商品价值.

  19. Experimetal study on monitoring ozonated water disinfection of fresh-cut fruit and vegetables by ORP%用ORP监控鲜切果蔬臭氧水消毒的实验研究

    Institute of Scientific and Technical Information of China (English)

    李尤; 刘钟阳; 都健

    2011-01-01

    研究了用氧化还原电位(ORP)监控臭氧水对鲜切果蔬的消毒灭菌过程,通过不同ORP的臭氧水消毒实验发现,将鲜切果蔬浸入ORP超过800mV的臭氧水中超过30s可以使细菌总数下降约2个数量级.通过改变臭氧浓度和水温的方法研究了臭氧水ORP的影响因素,得出了提高臭氧气体浓度和低温制冷有利于制取高ORP臭氧水的结论.结果表明,利用ORP监测臭氧水的消毒能力是可行的.%Monitoring the process of disinfection and sterilization of fresh-cut fruit and vegetables treated with ozonated water by ORP was studied.It was found that the number of total bacterial counts was reduced by the order of about 102 by immerging fresh-cut fruit and vegetables into ozonated water with ORP above 800mV over 30s through ozonated water disinfection and sterilization experiment with different values of ORP.The influence factors of ORP of ozonated water were studied by changing concentration of ozonated and water temperature.It was concluded that increasing the concentration of ozone and lowering the water temperature tend to produce ozonated water with high ORP.The study showed that it was feasible to monitor the ability of disinfection and sterilization of fresh-cut fruit and vegetables with ozonated water by ORP.

  20. 可食性莲子淀粉涂膜对鲜切菠萝品质的影响%Effects of edible lotus seed starch coating on quality of fresh-cut pineapple

    Institute of Scientific and Technical Information of China (English)

    林鸳缘; 郑宝东; 曾绍校; 张帆; 吴树铮

    2011-01-01

    Influence of edible lotus seed starch coating on quality of fresh-cut pineapple was studied. Fresh-cut pineapple was coated with 1%, 2% or 3% lotus seed starch pasting incorporating nisin an a natural antimicrobial agent; placed into plastic trays, and o ver-wrapped with PE film and then stored at (5 ± 1) ℃. Changes in ripening index, juioe leakage, colour, firmness and microbial growth were evaluated over time. The results showed that lotus seed starch coating retarded senescence, browning and softening. It also inhibited the growth of microorganisms effectively. The total microbial count coated with 2%, 3% lotus seed starch could be controlled under 105 (less than 105 was in line with fresh-cut food hygiene requirements) during tea days due to the synergistic effect of lotus seed starch coating and nisin. The results revealed that lotus seed starch coating maintained the quality attributes of fresh-cut pineapple effectively.%分别采用1%、2%、3%不同浓度莲子淀粉膜液(含天然防腐剂nisin)对鲜切菠萝片进行涂膜处理,再装入塑料盒中,用PE薄膜密封,于(5±1)℃贮藏.在贮藏过程中,对鲜切菠萝的成熟度、流汁率、色泽、硬度和细菌菌落总数等相关指标进行评价,研究可食性莲子淀粉涂膜对鲜切菠萝品质的影响.结果表明,涂膜处理能延缓鲜切菠萝的衰老、褐变、软化,有效抑制微生物的生长.2%、3%涂膜处理组贮藏10 d内,莲子淀粉膜与nisin的协同作用可使菌落总数控制在105以下,符合鲜切果蔬的食品卫生要求.因此,采用莲子淀粉涂膜处理能有效保持鲜切菠萝的品质.

  1. Effects of sodium alginate treatment in physiology and biochemistry changes of fresh-cut Xuehua pears%海藻酸钠处理对鲜切雪花梨生理生化的影响

    Institute of Scientific and Technical Information of China (English)

    田密霞; 胡文忠; 刘程惠; 王艳颖; 姜爱丽

    2015-01-01

    目的:研究海藻酸钠涂膜对鲜切雪花梨外观,质地及营养成分的影响。方法以鲜切雪花梨为材料,采用海藻酸钠(1%海藻酸钠+0.15%半胱氨酸+0.3%VC+0.6%醋酸)进行涂膜处理鲜切梨,测定经涂膜处理后的鲜切雪花梨的生理生化指标。结果雪花梨经过鲜切后在4℃和10℃贮藏期间,海藻酸钠涂膜处理明显减轻了鲜切雪花梨的褐变程度,抑制了多酚氧化酶和过氧化物酶的活性,保持较高的硬度、可滴定酸和VC含量,延缓了水分散失。结论海藻酸钠处理较好地保持了贮藏期间鲜切雪花梨的外观和质地。%Objective To research the effects of sodium alginate treatment on appearance, texture and nutritional ingredient of fresh-cut Xuehua pears.Methods Fresh-cut Xuehua pears were used as materials. Physiological and biochemical indicators were measured by sodium alginate (1 % sodium alginate, 0.15 %L-cysteine, 0.3 % VC and 0.6 % acetic acid) treatment on fresh-cut Xuehua pears.Results During storage at 4 and 10℃, the sodium alginate treatment could alleviated browning, inhibited polyphenol oxidase (PPO) and peroxidase (POD) activity, maintained a high firmness, Vc content and titratable acid content.Conclusion The data suggested that sodium alginate composite film could remain quality and appearance of the fresh-cut Xuehua pear during storage period.

  2. Effect of Dimethyl Dicarbonate(DMDC) as disinfectant on the quality of Fresh-cut flowering cabbages%DMDC杀菌对鲜切菜心品质的影响

    Institute of Scientific and Technical Information of China (English)

    王惠惠; 王维民; 陈于陇; 徐玉娟; 范梅红

    2013-01-01

    In the paper,the effect of total aerobic plate count and count of total yeasts and molds in the fresh-cut flowering cabbage treated by DMDC was investigated.And the sensory,nutritional quality and browning-related enzymes in fresh-cut flowering cabbage treated by DMDC were also determined at storage.This study aims to evaluate the effect of DMDC on fresh-cut flowering cabbage.It turned out that the total aerobic plate count and count of total yeasts and molds in the fresh-cut flowering cabbage treated by DMDC were significantly reduced (p <0.05).DMDC treatment made negative impact on firmness,color and chlorophyll at early storage of 8d,and had no significant influence on Vc and soluble sugar.However the treatment could reduce the loss of soluble protein and inhibit PPO and POD activities.As shown above,DMDC treatment can effectively reduce the occurrence of microorganisms on the surface of flowering cabbage,delay the browning-related enzymes'activity,and slow down the senescence and maintain the quality of flowering cabbage.%本文以鲜切菜心为原料,研究了二甲基二碳酸盐(DMDC)作为杀菌剂对其细菌、霉菌和酵母菌总数的影响,并通过测定鲜切菜心在贮藏期间外观品质、营养成分及其褐变相关主要酶的变化,对DMDC用于鲜切菜心的杀菌效果进行评价.结果表明:DMDC可以有效减少鲜切菜心中细菌(革兰氏阳性菌)、霉菌和酵母菌总数,对其贮藏前期的硬度、色泽、叶绿素含量的变化有一定影响,但是对Vc和可溶性糖无明显影响;并且可有效减少可溶性蛋白的损失,抑制多酚氧化酶(PPO)、过氧化物酶(POD)的活性.说明DMDC杀菌可以有效杀灭菜心表面微生物,延缓菜心贮藏期褐变相关酶活性的增加和衰老,有利于维持菜心的营养品质.

  3. HPLC法测定鲜切富士苹果中多酚类物质的研究%Quantitative determination of phenolics composition in fresh-cut ‘Fuji’ apples by high performance liquid chromatography

    Institute of Scientific and Technical Information of China (English)

    陈晨; 胡文忠; 姜波; 姜爱丽; 邹宇

    2015-01-01

    目的:分析鲜切富士苹果中多酚成分及含量。方法鲜切苹果多酚采用80%乙醇超声提取,利用高效液相色谱法法分析鲜切苹果中多酚成分,外标法定量分析各多酚组分的含量。结果10种多酚标准品的溶液浓度和检测响应值呈现出良好的线性关系,其相关系数r2均大于0.99,且回收率较超过95%,重复性好。鲜切富士苹果中主要含有绿原酸、表儿茶素、儿茶素、丁香酸和咖啡酸5种多酚物质,其中绿原酸和表儿茶素含量较高,分别为101.02±0.31μg/g和100.80±2.65μg/g。结论鲜切富士苹果富含具有抗氧化活性的多酚成分。%Objective To analyze the phenolics composition of fresh-cut ‘Fuji’ apples.Methods Phenolics were extracted from fresh-cut apples with 80% ethanol. Phenolics composition was analyzed by high performance liquid chromatography (HPLC). An external standard method was used for quantitative analysis.Results The results showed that 10 polyphenols could be separated and the calibrations curves were linear withr2>0.999 and the recovery rate was above 95%. HPLC analysis revealed that the main phenolic compounds in fresh-cut ‘Fuji’ apples were chlorogenic acid followed by chlorogenic acid, epicatechin, catechin, syringic acid and caffeic acid. The concentrations of chlorogenic acid and epicatechin were higher than others, with the values 101.02±0.31μg/g and 100.80±2.65μg/g, respectively.Conclusion Fresh-cut apple is rich in polyphenols with antioxidant activity.

  4. The Freshness-preserving Effects of Trehalose on Cut Rosa hybrida%海藻糖对月季切花的抗衰保鲜作用研究

    Institute of Scientific and Technical Information of China (English)

    马少敏; 王荣辉; 兰瑛; 韦函忠

    2011-01-01

    [Objective] This research aimed to study the freshness-preserving effects of trehalose on cut Rosa hvbrida. [Method] The fresh cut Rosa bybrida were treated with trehalose solution and the morphological indexes, fresh weight and relative plasma membrane permeability were compared. [Result] Comparing the value of the seventh day with the first day, the fresh weight of 5% trehalose treated decreased 28.3%, the relative plasma membrane permeability of 5% trehalose treated increased only 10.9 %. The vase life of 5% trehalose treated doubled than that of distilled water. [Conclusion] 5% trehalose could significantly improve the effect of freshness-preserving on cut flowers of Rosa hybrida.%[目的]研究海藻糖对月季鲜切花的抗衰保鲜作用、【方法】以不同浓度的海藻糖溶液作为瓶插液,比较形态指标、鲜重、相对外渗率的变化。[结果]海藻糖对月季切花具有一定的延缓失水作用,瓶插第7天时,5%海藻糖组的月季切花鲜重下降28.3%,低于蒸馏水对照组的50.0%和3%蔗糖组的47.7%;蒸馏水对照组第7天的相对外渗率比第1天上升79.8%,3%蔗糖组上升176.0%,而5%海藻糖组仅上升了10.9%;5%的海藻糖组的观赏日期比蒸馏水延长了1倍。【结论】5%的海藻糖作为月季切花瓶插液的作用最好,海藻糖对月季切花的抗衰保鲜作用是通过稳定细胞质膜来实现的。

  5. Role of ascorbic acid in the inhibition of polyphenol oxidase and the prevention of browning in different browning-sensitive Lactuca sativa var. capitata (L.) and Eruca sativa (Mill.) stored as fresh-cut produce.

    Science.gov (United States)

    Landi, Marco; Degl'Innocenti, Elena; Guglielminetti, Lorenzo; Guidi, Lucia

    2013-06-01

    Polyphenol oxidase (PPO) and, to a minor extent, peroxidase (POD) represent the key enzymes involved in enzymatic browning, a negative process induced by cutting fresh-cut produce such as lettuce (Lactuca sativa) and rocket salad (Eruca sativa). Although ascorbic acid is frequently utilised as an anti-browning agent, its mechanism in the prevention of the browning phenomenon is not clearly understood. The activity of PPO and POD and their isoforms in lettuce (a high-browning and low-ascorbic acid species) and rocket salad (a low-browning and high-ascorbic species) was characterised. The kinetic parameters of PPO and in vitro ascorbic acid-PPO inhibition were also investigated. In rocket salad, PPO activity was much lower than that in lettuce and cutting induced an increase in PPO activity only in lettuce. Exogenous ascorbic acid (5 mmol L(-1)) reduced PPO activity by about 90% in lettuce. POD did not appear to be closely related to browning in lettuce. PPO is the main enzyme involved in the browning phenomenon; POD appears to play a minor role. The concentration of endogenous ascorbic acid in rocket salad was related to its low-browning sensitivity after cutting. In lettuce, the addition of ascorbic acid directly inhibited PPO activity. The results suggest that the high ascorbic acid content found in rocket salad plays an effective role in reducing PPO activity. © 2012 Society of Chemical Industry.

  6. 臭氧水浓度对鲜切菠萝品质的影响%Effects of Ozone Water on Microorganism and Quality of Fresh-cut Pineapple

    Institute of Scientific and Technical Information of China (English)

    覃海元; 胡冰冰; 梁金姐; 韦春平

    2011-01-01

    The fresh-keeping effect of ozone water on fresh-cut pineapple was studied in this paper.Fresh-cut pineapple slices were soaked in 0、0.87、1.1、1.4、1.8 mg/L of ozone water for 2 min respectively,then packed in plastic trays,covered with PE film and stored at 5 ℃ for 0~9 days.The bacterial count,ascorbic acid,weight loss rate,soluble solids and color were measured respectively at 3-day interval during cooling storage.The results showed that the bacterial count of fresh-cut pineapple treated with 0、0.87、1.1、1.4、1.8 mg/L of ozone water were 5.3×105、9.3×104 、2.6×104 、3.6×103 、2.5×103 CFU/g respectively on the first day,and 4.7×108、2.4×107 、4.5×106 、4.1×105 、2.3×105 CFU/g On the 9th day.Ozone water teatment could inhibite browning,reduce weight loss and total soluble solid consumption,and had some effects on ascorbic acid content of fresh-cut pineapple.Ozone water treatment could extend the shelf life of fresh-cut pineapple.%为研究臭氧水浓度对鲜切菠萝的保鲜效果,分别采用0 mg/L、0.87 mg/L、1.1 mg/L、1.4 mg/L、1.8 mg/L的臭氧水浸泡处理鲜切菠萝2 min,装在塑料托盘中并用聚乙烯保鲜膜包裹,在冷藏(5℃)过程中每3 d测定鲜切的菌落总数、抗坏血酸、失重率、可溶性固形物和色泽。结果表明:经0 mg/L、0.87 mg/L、1.1 mg/L、1.4 mg/L、1.8 mg/L臭氧水处理的鲜切菠萝的菌落总数,在处理当天分别为5.3×105 CFU/g、9.3×104 CFU/g、2.6×104 CFU/g、3.6×103 CFU/g、2.5×103 CFU/g;第9 d分别为4.7×108 CFU/g、2.4×107 CFU/g、4.5×106 CFU/g、4.1×105 CFU/g、2.3×105 CFU/g;臭氧水处理可以抑制鲜切菠萝的褐变,减少失重和可溶性固形物消耗,对还原型抗坏血酸含量有一定影响。臭氧水处理可以延长鲜切菠萝的保质期。

  7. Effects of different fresh-cut forages and their hays on feed intake, digestibility, heat production, and ruminal methane emission by Boer x Spanish goats

    Science.gov (United States)

    Twenty-four yearling Boer (87.5%) × Spanish wethers (32.5 ± 0.36 kg body weight) were used in a 32-day experiment to assess effects of frequency of feeding condensed tannin (CT)-containing Sericea lespedeza (SL; Lespedeza cuneata) on ruminal methane emission. Fresh SL (15.3% CT) was fed at 1.3 time...

  8. 清洗方法对鲜切山药贮藏效果的影响%Study on storage effect of fresh-cut yam by different cleaning methods

    Institute of Scientific and Technical Information of China (English)

    董雷; 姚连芳; 高愿军

    2012-01-01

    The cleaning effects were determined by measuring the total numbers of colonies, MDA, weight lost and sensory quality of fresh cut yam, which was processed by using different concentrations of sodium hypochlorite, hydrogen peroxide and citric acid treatment. The results showed: sodium hypochlorite treatment can significantly reduce the total numbers of colonies of fresh-cut yam, but higher concentrations may damage the internal organization, and 0. 6% sodium hypochlorite solution was better, and then was hydrogen peroxide, citric acid was the worst.%采用不同浓度的次氯酸钠、双氧水和柠檬酸对鲜切山药进行处理,通过测定鲜切山药储藏期间的菌落总数、丙二醛含量、失重率以及感官品质来衡量清洗效果.结果表明:次氯酸钠处理可以明显降低鲜切山药的菌落总数,但浓度过高会破坏山药的内部组织,不利于其储藏;0.6%的次氯酸钠溶液处理效果较佳,双氧水次之,柠檬酸最差.

  9. Effect of Nano-chitosan Coating on Quality of Fresh-cut Zizania latifolia%纳米壳聚糖涂膜对鲜切茭白品质的影响

    Institute of Scientific and Technical Information of China (English)

    周静峰; 罗海波; 王隽; 江凯; 郁志芳

    2013-01-01

    研究了纳米壳聚糖涂膜对鲜切茭白品质的影响.鲜切茭白分别在去离子水(对照)、10g/L壳聚糖或10g/L壳聚糖+1.5 g/L纳米壳聚糖溶液中浸泡3min,自然晾干包装后于1±0.5℃下贮藏12d.贮藏过程中每3d测定鲜切茭白的白色指数(WI)、硬度、失重率及木质素、还原糖、抗坏血酸含量,PAL、SOD、CAT和POD活力.结果显示,纳米壳聚糖涂膜显著抑制了鲜切茭白WI值的下降和木质素含量的增加,维持了相对高的硬度及还原糖和抗坏血酸含量;贮藏12d后失重率为1.12%; PAL和POD活性显著低于对照(P<0.05),SOD和CAT活性显著高于对照(P<0.05).以上结果表明,纳米壳聚糖涂膜能有效延缓鲜切茭白褐变和木质化,提高抗氧化酶类活性,提示纳米壳聚糖涂膜具有商业上控制鲜切茭白品质劣变的潜在价值.%The effect of nano-chitosan coating on the quality of fresh-cut Z.latifolia was investigated.Fresh-cut Z.latifolia slices were dipped into deionised water (the control),10 g/L chitosan or the mixture of 10 g/L chitosan and 1.5 g/L nano-chitosan for 3 min,and then dried,packaged and finally stored for 12 days at 1±0.5 ℃.Changes in whiteness index (WI),firmness,weight loss,lignin,reducing sugar and ascorbic acid contents,phenylalanine ammonia-lyase (PAL),superoxide dismutase (SOD),eatalase (CAT) and peroxidase (POD) activities were evaluated at intervals of two days.The results showed that the nano-chitosan coating significantly inhibited the decline of WI value and the increase of lignin content,maintained relatively high firmness,reducing sugars and ascorbic acid contents of fresh-cut Z.latifolia.After a 12-day storage at 1±0.5 ℃,the weight loss of the fresh-cut Z.latifolia slices was 1.12%.The treatment also inhibited the activities of PAL and POD but promoted SOD and CAT activities compared with the control.The present findings indicated that the nano-chitosan coating could inhibit browning and

  10. Research progress of storage of fresh-cut fruits and juices by natural antimicrobials%天然防腐剂在鲜切水果和果汁保鲜中的研究进展

    Institute of Scientific and Technical Information of China (English)

    王怡; 陆利霞; 熊晓辉

    2012-01-01

    With improved living standard , the demand for low - calorie foods are increasing. The consumption of ready - to - eat fresh - cut fruits and fruit juices is gradually increased because of the attention to the food safety. Due to damaged tissue and form, fresh -cut fruits and fruit juices are easy polluted caused by pathogenic and spoilage microorganisms. If treated under inappropriate manipulation arid storage conditions, the product may be subject to microhm! diseases and spoilage. Quality loss in fresh -cut fruits and unpasteurized juices may be caused by microbiological, en-isymatic, chemical, or physical changes. Among these, microbiological cause is particularly important; first, micro-bial toxins or pathogenic microorganisms in the product are harmfal to the health of consumers; second , mierobial spoilage may incur economic losses to consumers. The use of antiseptic can effectively reduce mierobial pollution and enhance safety. Natural food additives can assure safety and maintain quality characteristics. Studies on the use of natural substances to prevent fresh - cut fruits and unpasteurized juices from microbiological spoilage have been significantly increased in recent years. This review summaries the different studies on the antimicrobial effectiveness to pathogenic and spoilage microorganisms in fresh - cut fruits and fruit juices by natural antimicrobials of animal, plant and mierobial origin%随着国民生活水平的提高,人们对低热量食品的需求不断增大,即食鲜切水果和果汁的消费也逐渐增加,它们的安全性越来越受到人们的重视.鲜切水果和果汁由于组织和形态被破坏极易受到病原微生物和腐败微生物的污染,如果加工或储存条件不当,极易造成微生物致病和腐败.微生物学、酶学、化学或物理学变化均能引起鲜切水果与未高温消毒果汁的质量损失.其中,微生物造成的损失非常重要,有两方面原因:一是微生物毒素或病原微

  11. Effect of mild heat pre-treatment on storage quality of fresh-cut Arctium lappa%热处理对鲜切牛蒡贮藏品质的影响

    Institute of Scientific and Technical Information of China (English)

    郑义; 李勇; 高兆建; 孙烨桐; 赵海睿

    2015-01-01

    Objective Toevaluate the effect of heat pre-treatment on storage quality of fresh-cutArctium lappaby central composite design (CCD)/response surface methodology (RSM).Methods Fresh-cutArctium lappa were treated under different time and temperature combinations and placed on simulated shelf at 23℃ ±2℃ for 5 d, then L* value, rate of weight loss and content of vitamin C of fresh-cutArctium lappa were measured. The adequacy of model equations for predicting the optimum response values were verified by the validated data.Results When the heat pre-treatment parameters were controlled at temperature of 46.5℃ and the processing time of 28.8 min, the L* value, rate of weight loss and content of vitamin C of fresh-cut Arctium lappa were 66.07, 0.78% and 6.16 mg/100 g, respectively. The experimental values agreed closely with the theoretical values predicted by RSM models, indicating that the models were adequate for the produce process.Conclusion Heat pre-treatment could effectively delay quality storage degradation of fresh-cut Arctium lappa.%目的:采用星点设计-响应面法研究了热处理对鲜切牛蒡贮藏品质的影响。方法对鲜切牛蒡进行不同时间和不同温度的热处理,处理后的牛蒡切片置于23℃±2℃条件下5 d(模拟货架期),对货架结束后的牛蒡色泽L*值、失重率和维生素C(VC)含量进行测定。采用响应面法建立了牛蒡色泽L*值、失重率和VC含量的二次多项数学模型,并验证了模型的有效性。结果热处理鲜切牛蒡的最佳处理温度为46.5℃,处理时间28.8 min,在此条件下,牛蒡色泽L*值、失重率和VC含量理论值分别为66.07、0.78%和6.16 mg/100 g。实际测得L*值66.13±1.7,失重率(0.79±0.03)%, VC含量(6.12±0.12) mg/100 g,与预测值基本一致,表明所建模型具有较好的预测性能,可用于指导生产实践。结论热处理可有效降低鲜切牛蒡贮藏品质的下降。

  12. PENGARUH CaCl2 DAN EDIBLE FILM TERHADAP PENGHAMBATAN CHILLING INJURY BUAH NANGKA KUPAS [Effect of CaCl2 and Edible Film on Chilling Injury Inhibition of fresh-cut Jackfruits

    Directory of Open Access Journals (Sweden)

    Ida Bagus Banyuro Partha1

    2009-06-01

    Full Text Available Effect of CaCl2 soaking and edible film coating to delay or inhibit chilling injury of freshly-cut jackfruit has been studied. The onset of chilling injury was monitored based on sadden increase of ethylene emission as measured on-line using CO2-laser driven photoacoustic spectrometer. Freshly cut edible part of ripe jackfruit was used as the research material. The fruit was soaked in 0%, 1%, 1,5%, 2% of CaCl2 for 15 minutes. After rinsing, sample were divided into two parts each for edible coating and control. The edible film was prepared by soaking of the samples for 30 seconds in solution of white bean (Phaseolus lunatus, L. edible coating, which was derived from our previous research. The samples were devided into two parts for destructive and non destructive analysis. Both were then stored at 4oC for 3 days, at which time the normal fruit suffer from chilling injury. For the non-destructive analysis, the samples were individually put in special cuvet and a flow-trough air system was connected to each cuvet for on-line ethylene monitoring. Data of real-time ethylene emission were collected automatically every 120 minutes during the three day cold storage. The other set of samples were put in a plascic bag and stored at 4oC for 3 days period. At the end of cold stored, the samples were let to adjust to room temperature for 1 hr before subjected to respiration rate, reducing sugars, total acidity, and texture analysis. Result indicated that soaking with CaCl2 and edible film coating of freshly-cut jackfruit delayed the on-set of chilling injury as indicated by late increase of ethylene emission. Based on pattern of ethylene emission during the three day storage and their respiration rate, the best treatment to delay chilling injury of fresly-cut jackfruit was soaking in CaCl2 2% in combination with edible film coating.

  13. Active packaging for fresh-cut broccoli using 1-methylcyclopropene in biodegradable sachet/ Embalagem ativa para brócolis minimamente processado utilizando 1-metilciclopropeno em sachê biodegradável

    Directory of Open Access Journals (Sweden)

    Marta de Toledo Benassi

    2006-07-01

    Full Text Available Fresh-cut broccoli florets were packed in polypropylene pots containing a sachet with 1- methylcyclopropene (1-MCP and sealed with biodegradable starch-based film. Broccoli was stored for 8 days at 12oC and after this time the color and the texture of the product were similar of the fresh broccoli, with no off-flavor development or decay. Active packaging with 1-MCP in a sachet was efficient to extent shelf life of broccoli florets retarding yellowing and vitamin C losses. It is an alternative of 1-MCP treatment for fresh-cut products and besides, the sachet can absorbs condensed water reducing spoilage and off-odor development.Brócolis minimamente processados foram embalados em bandejas de polipropileno com sachê contendo 1-metilciclopropeno (1-MCP e selado com filme biodegradável de amido. Os brócolis foram armazenados por 8 dias a 12oC e após este tempo a cor e a textura mantiveram-se similares às do produto fresco, sem desenvolvimento de odor não característico ou podridão. A embalagem ativa contendo 1-MCP na forma de sachê foi eficiente no aumento da vida de prateleira de brócolis, retardando o amarelecimento e a perda de vitamina C. Esta é uma alternativa para o tratamento com 1-MCP para produtos minimamente processados e além disso, o sachê pode absorver a água condensada, reduzindo a deterioração e o desenvolvimento de odor não característico.

  14. Effects of different cleaning steri l ization methods on preservation of fresh-cut Hang cabbage%清洗杀菌方式对鲜切杭白菜保鲜效果的影响

    Institute of Scientific and Technical Information of China (English)

    雷昊; 谢晶; 乔永祥; 张栓栓; 陈莹莹

    2016-01-01

    以杭白菜为对象,对新鲜杭白菜进行鲜切处理后,研究不同清洗杀菌方式(次氯酸钠溶液:有效氯为0.1 g/L;电解水:pH 为2.3;臭氧水:活氧浓度为1.8 mg/L)对鲜切杭白菜保鲜效果的影响。结果表明:臭氧水清洗能更好地保持鲜切杭白菜感官品质,使菌落总数维持在较低的水平,显著地延缓抗坏血酸和叶绿素含量的降低(P<0.05),有效地延长杭白菜货架期长达6d。%Fresh Hang cabbage,through fresh cutting,was selected to study the effects of preservation with different cleaning sterilization methods (sodium hypochlorite solution with active chlo-rine with 0.1 g/L;electrolysis of water with:pH 2.3;ozone water:active oxygen concentration of 1 .8 mg/L).The results showed that:ozone water was preferable to maintain fresh-cut Hang cabbage sen-sory quality,bringing the total number of colonies maintained at a low level,significantly delayed ascorbic acid content (P<0.05 ), chlorophyll content reduction,and effectively extended the shelf life of Hang cabbage for 6 d.

  15. Antibacterial effect of 405±5nm light emitting diode illumination against Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella on the surface of fresh-cut mango and its influence on fruit quality.

    Science.gov (United States)

    Kim, Min-Jeong; Tang, Chee Hwa; Bang, Woo Suk; Yuk, Hyun-Gyun

    2017-03-06

    To investigate a potential of 405±5nm light emitting diode (LED) as a novel technology for food preservation, the antibacterial effect of 405±5nm LED on Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella spp. on the surface of fresh-cut mango and its influence on fruit quality were evaluated at different storage temperatures. LED-illumination inactivated 1.0-1.6 logCFU/cm(2) of populations at 4 and 10°C for 36-48h (total dose, 2.6-3.5kJ/cm(2)) regardless of bacterial species, while those on non-illuminated mange remained unchanged or slightly increased during storage. At 20°C for 24h (total dose, 1.7kJ/cm(2)), non-illuminated E. coli O157:H7 and Salmonella gradually grew, whereas LED-illumination reduced 1.2 log of Salmonella and inhibited the growth of E. coli O157:H7. Unlike these, non-illuminated L. monocytogenes cells rapidly increased to 7.3 log, while illuminated cells reached 4.6 log, revealing that LED-illumination delayed their growth. There were no significant (P>0.05) differences in color, antioxidant capacity, ascorbic acid, β-carotene, and flavonoid between non-illuminated and illuminated cut mangoes, regardless of storage temperature. These results suggest that 405±5nm LEDs in combination with chilling temperatures could be applied to preserve fresh-cut fruits without deterioration of physicochemical quality of fruits at food establishments, minimizing the risk of foodborne disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. 茉莉酸甲酯处理抑制鲜切梨褐变机理的研究%Study on the mechanism of browning inhibited by methyl jasmonate treatment on fresh-cut pear

    Institute of Scientific and Technical Information of China (English)

    王艳颖; 胡文忠; 姜波; 金黎明

    2012-01-01

    In order to develop new methods in keeping fruits and vegetables fresheness, effects of different concentrations of methyl jasmonate treatment on enzymatic browning of fresh-cut crystal pear during room temperature storage were investigated.The results showed that the relative conductivity increased rapidly, the content of polyphenol and the activity of polyphenol oxidase (PPO) increased then formed enzymatic browning showed the L* value decreasing gradually in pear after cutting, and the damage from cutting aggravated membrane lipid peroxidation, and induced the activity of peroxidase (POD), superoxide dismutase (SOD), catalase(CAT) to remove excess free radicals for increasing the stress resistance of the fruit. Methyl jasmonate treatment protected the cell membranes, inhibited the leakage of phenolic compounds and PPO activity, weaken the trend of enzymatic browning;and it delayed the rising of POD, SOD, CAT activity in order to maintain longer time the capacity of scavenging free radical thus postponed the membrane lipid peroxidation process.Especially, ltJmol/L methyl jasmonate treatment was more effective in maintaining the storage quality of fresh-cut pears and delaying the aging of fresh-cut pear%为探索鲜切果蔬保鲜的新途径,以鲜切水晶梨为试材,研究了不同浓度的茉莉酸甲酯对常温下贮藏的鲜切梨酶促褐变的影响。结果表明,梨经过鲜切后,相对电导率快速上升,多酚含量和PPO活性增加而发生酶促褐变,L^+值逐渐下降;而且切割伤害加剧了膜脂过氧化,进而诱导了POD、SOD、CAT活性的增加以清除过剩的自由基,提高果实的抗逆性。而茉莉酸甲酯处理保护了细胞膜结构,抑制了酚类物质外泄和PPO活性,减弱了酶促褐变的趋势;同时它也延缓了POD、SOD、CAT活性的上升以维持较长时间清除自由基的能力,从而推迟了膜脂过氧化的进程。尤其是1μmlol/L的茉莉酸甲酯处理更有

  17. Dual-species biofilm formation by Escherichia coli O157:H7 and environmental bacteria isolated from fresh-cut processing facilities.

    Science.gov (United States)

    Liu, Nancy T; Nou, Xiangwu; Lefcourt, Alan M; Shelton, Daniel R; Lo, Y Martin

    2014-02-03

    Biofilm formation is a mechanism adapted by many microorganisms that enhances the survival in stressful environments. In food processing facilities, foodborne bacterial pathogens, which many are poor biofilm formers, could potentially take advantage of this protective mechanism by interacting with other strong biofilm producers. The objective of this study was to determine the influence of bacteria native to fresh produce processing environments on the incorporation of Escherichia coli O157:H7 in biofilms. Bacteria strains representing 13 Gram-negative species isolated from two fresh produce processing facilities in a previous study were tested for forming dual-species biofilms with E. coli O157:H7. Strong biofilm producing strains of Burkholderia caryophylli and Ralstonia insidiosa exhibited 180% and 63% increase in biofilm biomass, and significant thickening of the biofilms (B. caryophylli not tested), when co-cultured with E. coli O157:H7. E. coli O157:H7 populations increased by approximately 1 log in dual-species biofilms formed with B. caryophylli or R. insidiosa. While only a subset of environmental isolates with strong biofilm formation abilities increased the presence of E. coli O157:H7 in biofilms, all tested E. coli O157:H7 exhibited higher incorporation in dual-species biofilms with R. insidiosa. These observations support the notion that E. coli O157:H7 and specific strong biofilm producing bacteria interact synergistically in biofilm formation, and suggest a route for increased survival potential of E. coli O157:H7 in fresh produce processing environments.

  18. Effects of concentrate crude protein content on nutrient digestibility, energy utilization, and methane emissions in lactating dairy cows fed fresh-cut perennial grass.

    Science.gov (United States)

    Hynes, D N; Stergiadis, S; Gordon, A; Yan, T

    2016-11-01

    Although many studies have investigated mitigation strategies for methane (CH4) output from dairy cows fed a wide variety of diets, research on the effects of concentrate crude protein (CP) content on CH4 emissions from dairy cows offered fresh grass is limited. The present study was designed to evaluate the effects of cow genotype and concentrate CP level on nutrient digestibility, energy utilization, and CH4 emissions in dairy cows offered fresh-grass diets. Twelve multiparous lactating dairy cows (6 Holstein and 6 Holstein × Swedish Red) were blocked into 3 groups for each breed and assigned to a low-, medium-, or high-CP concentrate diet [14.1, 16.1, and 18.1% CP on a dry matter (DM) basis, respectively], in a 3-period changeover study (25d per period). Total diets contained (DM basis) 32.8% concentrates and 67.2% perennial ryegrass, which was harvested daily. All measurements were undertaken during the final 6d of each period: digestibility measurements for 6d and calorimetric measurements in respiration chambers for 3d. Feed intake and milk production data were reported in a previous paper. We observed no significant interaction between concentrate CP level and cow genotype on any parameter. Concentrate CP level had no significant effect on any energy utilization parameter, except for urinary energy output, which was positively related to concentrate CP level. Similarly, concentrate CP content had no effect on CH4 emission (g/d), CH4 per kg feed intake, or nutrient digestibility. Cross breeding of Holstein cows significantly reduced gross energy, digestible energy, and metabolizable energy intake, heat production, and milk energy output. However, cow genotype had no significant effect on energy utilization efficiency or CH4 parameters. Furthermore, the present study yielded a value for gross energy lost as CH4 (5.6%) on fresh grass-based diets that was lower than the widely accepted value of 6.5%. The present findings indicate that reducing concentrate CP

  19. Establishment of growth model of Listeria monocytogenes in Fresh-cut iceberg lettuce%鲜切结球莴苣中单增李斯特菌生长预测模型的建立

    Institute of Scientific and Technical Information of China (English)

    张引成; 尹晓婷; 雷云; 韦莹莹; 潘磊庆; 屠康

    2013-01-01

    为建立不同温度下鲜切结球莴苣中单增李斯特菌生长模型,将单增李斯特菌接种到鲜切结球莴苣表面,并于不同温度下贮藏,获得其在4、8、16、24和32℃下的生长数据,选用Gompertz模型进行拟合,建立初级生长模型.在此基础上建立二级模型研究温度对初级模型中单增李斯特菌生长动力学参数的影响,并进行数学检验.结果表明,对最大比生长速率和延滞时间建立平方根模型,结果呈良好的线性关系,相关系数R2分别为0.977 2和0.984 7,所建立的预测模型能很好地描述不同温度下单增李斯特菌的生长动态.%This paper was designed to establish the growth model of Listeria monocytogenes in fresh-cut iceberg lettuce in different temperatures.The L.Monocytogenes was inoculated to the surface of fresh-cut iceberg lettuce and then preserved in temperature of 4 ℃,8 ℃,16 ℃,24℃,32 ℃.Gompertz model was selected as the primary model.A secondary model was created to study the effects of temperature on growth kinetics parameters of Listeria monocytogenes in the primary model.Mathematical evaluation was also conducted.The results showed that the regression of Belehradek model well described the effect of temperatures on the maximumgrowth rate and the lag phase,and correlation coefficients of determination were 0.9772,0.9847,respectively.Therefore,the model can predict the growth of L.monocytogenes in fresh-cut iceberg lettuce perfectly.

  20. 真空处理对鲜切莲藕褐变控制的效果%Effect of vacuum processing on browning control of fresh-cut lotus tubes

    Institute of Scientific and Technical Information of China (English)

    张心怡; 曹娜; 杜传来; 姜丽; 郁志芳

    2015-01-01

    Objective To investigate the effect of vacuum processing on browning control of fresh-cut lotus root. Methods The physiological and biochemical indexes includingL*value, respiration intensity, the content of Vc and malondialdehyde, and browning degree of fresh cut lotus roots under normal pressure and vacuum condition both at 4℃ were detected.Results Compared with the atmospheric pressure, vacuum processing could significantly slow down the decreasing rate ofL * value and Vc, and the increasing rate of browning degree, inhibit the respiratory intensity, and reduce the methane dicarboxylic aldehyde (MDA) content as well as the activities of polyphenol oxidase (PPO) and peroxidase (POD) at early stage of storage. Conclusion Vacuum processing can significantly inhibit the browning of fresh cut lotus root during storage.%目的:探讨真空条件对控制鲜切莲藕褐变的影响。方法通过测定4℃常压和真空两种条件下鲜切莲藕 L*值、呼吸强度、Vc 和丙二醛含量及褐变度等生理生化指标,研究真空条件对鲜切莲藕品质的影响。结果与相同温度下的常压贮藏相比,真空显著有利于鲜切莲藕感官品质保持,减慢 L*值的下降和 Vc 的损失,抑制呼吸强度、丙二醛和褐变度的上升,并能有效抑制多酚氧化酶(PPO)和过氧化物酶(POD)的活性。结论真空处理能够显著抑制鲜切莲藕贮藏期间的褐变进程。

  1. 中低温蒸汽处理对鲜切胡萝卜片减菌效果及其品质的影响%Effect of steam sterilization treatments on the quality of fresh-cut carrot slices

    Institute of Scientific and Technical Information of China (English)

    周明晖; 刘书来; 丁玉庭

    2012-01-01

    To explore the effects of steam sterilization treatments on the quality of vegetables,fresh-cut carrot slices were treated by steam with different temperature(50~100℃).The results showed that,with the increase of temperature and time of steam,the amount of microorganisms,moisture,carotenoids,firmness and color of the fresh-cut carrot slices decreased significantly(P0.05).When the low temperature steam(50~70℃) was used for 600s,the amount of microorganisms decreased more than 3lg(cfu/g),with moisture loss below 5% and carotenoids retention above 85%.In addition,it had little effects on the firmness and color of samples.While the moderate temperature steam(80~100℃) and the traditional boiling water blanching had more harmful effects on the carrot slices'quality.It can be concluded that low temperature steam treatments can reduce the amount of microorganisms of fresh-cut carrot slices and keep their quality as much as possible.%以鲜切胡萝卜片为研究对象,采用中低温蒸汽(50~100℃)进行减菌处理,分析了蒸汽处理过程中鲜切胡萝卜片品质指标的变化。结果表明,鲜切胡萝卜片的菌落总数、水分、类胡萝卜素、硬度、色泽等指标均随处理温度及时间的增加而显著减少(P〈0.05)。采用低温蒸汽(50~70℃)处理600s,对胡萝卜片的减菌效果明显,且失水率小于5%,类胡萝卜素保留高于85%,对蔬菜的硬度和色泽影响较小。而经中温蒸汽(80~100℃)及传统的沸水热烫处理后的胡萝卜片,其品质质地明显降低。因此,低温蒸汽减菌处理能有效降低胡萝卜片中的菌落总数,并可最大程度保护其品质质地。

  2. Effects of Chitosan Coating on Factors Relating to Enzymatic Browning of Fresh-Cut Lotus Root Slices%壳聚糖对鲜切莲藕酶促褐变相关因子的影响

    Institute of Scientific and Technical Information of China (English)

    汪伟; 张伟; 孙莹; 高成; 朱丽琴

    2014-01-01

    The effects of chitosan coating of fresh-cut lotus root slices on the quality and relating factors in enzymatic browning were studied to explore the mechanism of chitosan in inhibition of enzymatic browning of fresh-cut lotus roots.Fresh-cut lotus root slices were coated with chitosan in different concentrations ( 1%, 2%) and then stored at 4℃.The results showed that chitosan treatment significantly inhibited the increase of browning degree and weight loss rate, and maintained higher vitamin C and total phenolic content.Chitosan coating significantly inhibited the production of superoxide free radicals ( O2 · -) and H2 O2 content,maintained high catalase activity,and significantly inhibited the activity of polyphenol oxidase and peroixdase during stor-age.Treatment with 2%chitosan showed better effect.%为探讨壳聚糖对鲜切莲藕的酶促褐变抑制机理,在4℃下对鲜切莲藕进行壳聚糖涂膜保鲜试验,研究了不同质量分数(1%、2%)壳聚糖对鲜切莲藕品质的影响和酶促褐变相关因子的影响。结果表明:壳聚糖处理显著抑制了鲜切莲藕贮藏过程中的褐变和水分损失,保持较高的维生素C和总酚含量,显著抑制了超氧阴离子(O2·-)和过氧化氢(H2O2)的积累,保持较高的过氧化氢酶(CAT)活性,并显著抑制了多酚氧化酶(PPO)和过氧化物酶(POD)活性。且2%的壳聚糖处理效果更好。

  3. Efeito do cloreto de cálcio na qualidade de abacaxi 'Pérola' minimamente processado Effect of calcium chloride on quality of fresh-cut 'Pérola' pineapple

    Directory of Open Access Journals (Sweden)

    Lucimara Rogéria Antoniolli

    2003-09-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos do cloreto de cálcio na qualidade do abacaxi 'Pérola' minimamente processado. Os tratamentos, arranjados em delineamento inteiramente casualizado e dispostos em esquema fatorial 3x5, consistiram das concentrações de CaCl2 e dos períodos de armazenamento, com três repetições. Frutos previamente sanitizados foram descascados mecanicamente, fatiados manualmente e imersos em solução de CaCl2 a 1% e a 2% e em água (controle, durante 30 segundos. As fatias foram acondicionadas em embalagens de polietileno tereftalato e mantidas à temperatura de 4±1°C durante períodos de 0, 3, 6, 9 e 12 dias. A textura não foi influenciada por nenhum dos fatores estudados. Constatou-se menor atividade peroxidásica nos frutos tratados com CaCl2 2%. Quanto à coloração, a imersão em solução de CaCl2 1% resultou em fatias mais escurecidas, com menor valor L* e maior valor a* ao final do período de armazenamento. A utilização de CaCl2 em abacaxi 'Pérola' minimamente processado não proporciona efeitos benéficos na textura, e interfere negativamente na coloração da polpa do fruto.The objective of this research was to evaluate the effects of calcium chloride on quality of fresh-cut 'Pérola' pineapple. The experimental design was a completely randomized in a 3x5 factorial scheme, and the treatments were represented by the CaCl2 concentration and storage time, each one with three replicates. Fruits were sanitized, peeled mechanically, sliced manually and dipped into water (control and in CaCl2 solutions (1% and 2% for 30 seconds. Slices were placed in polyethylene terephtalate packages and stored at 4±1°C during periods of 0, 3, 6, 9 and 12 days. Texture was not influenced by any of the studied factors. Smaller peroxidase activity in the samples submitted to CaCl2 2% was verified. Fresh-cut pineapple slices dipped in CaCl2 1% showed more browning, presenting smaller L* value and larger a* value at

  4. Research on preservation effects of ozone treatment combined with modified atmosphere packaging of fresh-cut vegetable%臭氧协同气调包装对鲜切叶菜的保鲜作用研究

    Institute of Scientific and Technical Information of China (English)

    华璐云; 雷桥; 谢晶

    2012-01-01

    采用臭氧水处理鲜切大白菜,并进行气调包装贮藏,通过正交实验法分析相关生理指标与保鲜效果,主要研究了4℃贮藏期间菌落总数、失重率、细胞膜透性、多酚氧化酶活性、VC含量和感官品质的变化。实验结果显示:臭氧水处理结合气调包装能有效控制微生物数量,保护了细胞膜透性及降低了VC含量的损失,并对多酚氧化酶有抑制作用,感官品质优良,可使鲜切白菜在4℃条件下保藏至20d以上。极差分析表明:优化的工艺参数为1.44mg/L的臭氧水处理5min协同5%O2/20%CO2/75%N2的气调包装。%Physiological indexes and preservation effects of fresh cut cabbage treated with ozone water combined with modified atmosphere packaging were studied.Analysis included total bacteria counts,weight loss rate,membrane permeability,PPO activity,VC content and sensory qualities during storage at 4℃.Results indicated that ozone treatment combined with modified atmosphere packaging was effective in controlling the total bacteria counts and protecting membrane permeability,and decreasing the loss of VC content and PPO activity.The shelf-life of fresh-cut cabbage was more than 20 days at 4℃ with better sensory qualities.The optimized preservation conditions by range analysis were as follows:treating fresh-cut cabbage with 1.44mg/L ozone for 5min and packing with 5% O2/20% CO2/75% N2.

  5. UVA, UVB and UVC Light Enhances the Biosynthesis of Phenolic Antioxidants in Fresh-Cut Carrot through a Synergistic Effect with Wounding

    Directory of Open Access Journals (Sweden)

    Bernadeth B. Surjadinata

    2017-04-01

    Full Text Available Previously, we found that phenolic content and antioxidant capacity (AOX in carrots increased with wounding intensity. It was also reported that UV radiation may trigger the phenylpropanoid metabolism in plant tissues. Here, we determined the combined effect of wounding intensity and UV radiation on phenolic compounds, AOX, and the phenylalanine ammonia-lyase (PAL activity of carrots. Accordingly, phenolic content, AOX, and PAL activity increased in cut carrots with the duration of UVC radiation, whereas whole carrots showed no increase. Carrot pies showed a higher increase compared to slices and shreds. Phenolics, AOX, and PAL activity also increased in cut carrots exposed to UVA or UVB. The major phenolics were chlorogenic acid and its isomers, ferulic acid, and isocoumarin. The type of UV radiation affected phenolic profiles. Chlorogenic acid was induced by all UV radiations but mostly by UVB and UVC, ferulic acid was induced by all UV lights to comparable levels, while isocoumarin and 4,5-diCQA was induced mainly by UVB and UVC compared to UVA. In general, total phenolics correlated linearly with AOX for all treatments. A reactive oxygen species (ROS mediated hypothetical mechanism explaining the synergistic effect of wounding and different UV radiation stresses on phenolics accumulation in plants is herein proposed.

  6. Effect of chitosan edible coating incorporated with origanum essential oil on preservation of fresh-cut pineapple%壳聚糖涂膜与牛至精油复配对鲜切菠萝的保鲜作用

    Institute of Scientific and Technical Information of China (English)

    冯可; 胡文忠; 姜爱丽; 萨仁高娃; 徐永平

    2015-01-01

    Objective To study the influence of chitosan edible coating and incorporated with oregano essential oil on preservation of fresh-cut pineapple.Methods The values of the firmness, Vc content, peroxidase (POD), polyphenol oxidase (PPO), catalase (CAT) and lipoxygenase (LOX) activity of fresh-cut pineapple were analyzed by processed with chitosan edible coating incorporated with 0.1%, 0.3% and 0.5% of oregano essential, respectively, with water and chitosan edible coating processing as control.Results The processing of chitosan coating with 0.5% oregano essential oil could slow down softening of the tissue; the processing with 0.1% of oregano essential oil could maintain the decline of Vc content slowly; the POD and CAT activity of fresh cut pineapple were declined when it was processed with chitosan coating containing 0.3% and 0.5% oregano essential oil, and appeared increasing trend under other processing condition. The PPO and LOX activity with chitosan edible coating processing were lower than those of the control. Conclusions Chitosan edible coating incorporation with oregano essential oil would extend shelf-life of fresh-cut pineapple at the condition of keeping nutrition ingredient.%目的:研究壳聚糖涂膜及与牛至精油复配对鲜切菠萝的保鲜的影响。方法在低温环境中,按照0.1%、0.3%和0.5%不同浓度的牛至精油与壳聚糖复配,并分别以水、壳聚糖涂膜处理为对照,分析不同处理方式对鲜切菠萝硬度、Vc 含量、过氧化物酶(POD)、多酚氧化酶(PPO)、过氧化氢酶(CAT)和脂氧合酶(LOX)活性的影响。结果壳聚糖涂膜与0.5%的牛至精油复配后可减缓组织软化;与0.1%牛至精油复配可以维持Vc含量的缓慢降低。在不同处理组中,当含有0.3%和0.5%牛至精油时,鲜切菠萝的POD和CAT活性则呈下降趋势,而其他处理组则显著升高;当含有壳聚糖处理组时,其 PPO和LOX活性则低于对照组。结论壳聚糖与牛至

  7. Avaliação da qualidade do abacaxi "Pérola" minimamente processado armazenado sob atmosfera modificada Evaluation of quality in fresh-cut 'Pérola' pineapple stored under modified atmosphere

    Directory of Open Access Journals (Sweden)

    Juliana Costa Bueno Santos

    2005-04-01

    Full Text Available Objetivou-se com este trabalho verificar o efeito da atmosfera modificada ativa sobre a qualidade do abacaxi minimamente processado. Assim, foram avaliadas as modificações físico-químicas, sensorial e microbiológica do abacaxi 'Pérola' minimamente processado submetido a diferentes atmosferas modificadas passiva e ativamente (controle - atmosfera modificada passiva; 5%O2 + 5%CO2 , 2%O2 + 10%CO2. A atmosfera com 2% O2 + 10% CO2 determinou menor perda de líquido drenado, embora tal perda tenha sido desprezível. A atmosfera modificada ativa preveniu o amaciamento do abacaxi minimamente processado, reduzindo a atividade da poligalacturonase e solubilização péctica. As variáveis pH e vitamina C não foram significativamente afetadas pela atmosfera modificada ativa. Maiores valores de sólidos solúveis totais (SST foram encontrados nos frutos sob atmosfera 5% O2 + 5% CO2 e no caso dos açúcares solúveis o tratamento com 2% O2 + 10% CO2 resultou em maiores teores. De acordo com análise sensorial, os frutos sob atmosfera modificada passiva se sobressaíram com relação ao sabor, aparência e cor. A análise microbiológica detectou valores insignificantes para fungos filamentosos, leveduras e coliformes a 35° e 45°C em todos os tratamentos. Conclui-se que o abacaxi 'Pérola' minimamente processado pode ser armazenado por 8 dias, a 5°C, sob atmosfera modificada passiva.The goal of this work was to verify the effect of active modified atmosphere on the quality of fresh-cut pineapple. Physical-chemical, sensory and microbiological changes of fresh-cut 'Pérola' pineapple treated with passive (control and active (5%O2 + 5%CO2; 2%O2 + 10%CO2 modified atmosphere were studied. The 2%O2 + 10%CO2 combination promoted the lowest loss of drained liquid, although they were negligible. Active modified atmosphere prevented the softening of fresh cut pineapples, reducing the poligalacturonase activity and pectin solubilization. The pH and ascorbic

  8. Anti-browning effect of disodium stannous citrate on fresh-cut lotus%柠檬酸亚锡二钠对鲜切莲藕护色作用的研究

    Institute of Scientific and Technical Information of China (English)

    金定樑; 夏文水

    2011-01-01

    柠檬酸亚锡二钠(DSC)是一种新型护色剂.将DSC用于鲜切莲藕预处理阶段,抑制莲藕多酚氧化酶活力及褐变,探讨影响DSC对鲜切莲藕片护色作用的因素,并与其他常用护色剂的护色效果进行对比.结果表明:DSC对鲜切藕产品低温保藏期间的褐变和多酚氧化酶活力都有很好的抑制作用,在pH 3~6条件下用0.05%~0.2% DSC浸泡液处理15 min后,鲜切藕产品可保持较低的褐变度和多酚氧化酶活力,同时在4℃、20 d内DSC的护色效果稳定;与其他常用护色剂比较,在0.1%的等量护色剂浓度下,DSC护色效果优于柠檬酸、抗坏血酸、异抗坏血畦钠,与亚硫酸氢钠效果相当.%Disodium stannous citrate(DSC)is an effective sntibrowning agent. This investigation was conducted to determine the efficacy of DSC as a browning control agent for use on fresh-cut lotus. Fresh-cut lotus products are prone to browning during the low-temperature preservation, The relative effectiveness of these antibrowning agents for inhibition of enzymatic browning in fresh-cut lotus was determined in terms of colour and enzyme activity measurements with respect to time for approximately 20 days storage period at 4 ℃. The fresh-cut lotus were dipped in treatment solutions for some time, then drained grid placed ;n containers. The resuhs showed that, DSC has good controlling browning effects on the lotus products. Including the enzymatic browning and non-enzymatic browning) The best concentration of DSC is 0. 05 % ~ 0. 2%, the processing lime for 15 min. pH range of applications from 3 to 6. And the effect of DSC in different temperatures on the color-preservation effect includes but not limited, and has the function of stability for the products during the shelf life. Compared with other ancibrowning agents commonly.The effect of 0.1%DSC has the more obvious effects, quite close to the effect of sodium bisulfite. The research has a theoretic guidance for

  9. Influência da embalagem de polietileno de baixa densidade e da temperatura na conservação do repolho minimamente processado Effects of low density polyethylene packaging and temperature in the conservation of fresh-cut cabbage

    Directory of Open Access Journals (Sweden)

    Maria M. Rinaldi

    2004-08-01

    Full Text Available Neste trabalho, foi estudado o efeito da embalagem de polietileno de baixa densidade e da temperatura de armazenagem na conservação de repolho minimamente processado. Os repolhos, previamente resfriados à temperatura de 10 ºC, foram submetidos à seleção, lavagem, corte em quatro partes com a retirada do talo central, sanitização, corte em tiras, enxágüe, centrifugação, pesagem e acondicionamento em embalagens plásticas de polietileno de baixa densidade (70 µm e armazenados em câmaras frias nas temperaturas de 1 e 10 ºC por 20 dias. Avaliaram-se dióxido de carbono, oxigênio e etileno na atmosfera interna da embalagem, bem como pH, acidez titulável, sólidos solúveis totais, vitamina C, perda de massa fresca e relação sólidos solúveis totais/acidez no repolho minimamente processado. O delineamento estatístico utilizado foi o inteiramente casualizado, com três repetições. Os parâmetros de análise, com exceção da vitamina C, perda de massa fresca e etileno, apresentaram variação significativa entre as temperaturas e dias de armazenamento. O repolho armazenado na temperatura de 1 ºC apresentou vida de prateleira ao redor de 15 dias, significativamente maior que a 10 ºC. Nesta última, no 8º dia de armazenamento, o produto encontrava-se totalmente deteriorado, sem condições de comercialização e consumo.This research studied the effect of low density polyethylene packaging and storage temperature on the preservation of fresh-cut (minimally processed cabbage. The cabbages, previously cooled to a temperature of 10 ºC, were selected, washed, cut in four parts (with the central stalk removed, sanitized, cut in strips, rinsed, put in the centrifuge, weighed and stored in plastic packaging of low density polyethylene (70 µm, and then stored in cold chambers at temperatures of 1 and 10 ºC for 20 days. The following aspects were evaluated: carbon dioxide, oxygen and ethylene in the internal atmosphere of the package

  10. 不同清洗方式对鲜切鸡毛菜保鲜效果的影响%Effect of different washing agents on the preservation of fresh-cut Chinese little greens

    Institute of Scientific and Technical Information of China (English)

    林永艳; 谢晶; 朱军伟; 高志立; 王肽

    2012-01-01

    实验采用臭氧水、电解水、次氯酸钠、超声波对鲜切鸡毛菜进行清洗,自来水清洗作为对照。通过测定贮藏期间叶绿素、Vc亚硝酸盐、细菌总数、感官品质等来比较清洗效果。实验结果表明,臭氧水和超声波处理的样品在杀菌、保持营养物质及感官上的效果相对其他处理的样品要好,贮藏至14d仍有商品价值和食用价值,可作为鲜切鸡毛莱加工过程中的处理方式。%Ozone water,brine electrolysis,sodium hypochlorite and ultrasonic were used to clean the fresh-cut Chinese little greens with tap-water as the control. The chlorophyll,Vc content, nitrite,total bacteria,and sensory quality were determined to evaluate the washing effect. The result indicated that ozone water and ultrasonic had better effect on sterilization ,maintaining nutrient substance and sensory quality than others,and Chinese little greens kept them commodity and edible value until the 14th day, Ozone water and ultrasonic could be used as the cleaning method in the processing of fresh-cut Chinese little greens.

  11. Filmes plásticos e ácido ascórbico na qualidade de araticum minimamente processado Plastic packaging film and ascorbic acid treatment on the quality of fresh cut araticum

    Directory of Open Access Journals (Sweden)

    Manoel Soares Soares Júnior

    2007-12-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos do ácido ascórbico e do tipo de filme plástico como embalagem na qualidade do araticum minimamente processado e mantido sob refrigeração. O ácido ascórbico não evitou o escurecimento do araticum minimamente processado. Independentemente do tipo de embalagem, a acidez titulável aumentou com o tempo. A embalagem de policloreto de vinila ou polietileno de baixa densidade promoveu uma significativa perda de massa se comparada com a a laminada a vácuo. A embalagem laminada a vácuo propiciou vida-de-prateleira mais longa ao produto, o qual permaneceu com aparência adequada e qualidade comercial até o sétimo dia do armazenamento. A vida-de-prateleira dos demais tratamentos alcançou somente três dias.This study was aimed at evaluating the effect of ascorbic acid and type of plastic packaging film on the quality of refrigerated fresh cut araticum. Ascorbic acid did not prevent fresh cut araticum from darkening. Regardless of the type of plastic packaging, the fruit titrable acidity increased with time. Packing with polyvynil chloride or with low density polyethylene promoted a significant mass loss compared to laminate vacuum packaging. Laminate vacuum packaging increased the shelf life of the product up 7 days, maintaining its commercial quality and appearance. The shelf life of the other treatments reached 3 days only.

  12. Effects of calcium ascorbate on quality of fresh-cut iceberg lettuce%抗坏血酸钙对鲜切生菜品质的影响

    Institute of Scientific and Technical Information of China (English)

    张留圈; 李艺; 梁颖; 丁莹; 张娟; 刘贤金

    2016-01-01

    The influence of concentrations and time duration of calcium ascorbate treatment on the quality of fresh⁃cut iceberg lettuce during storage at 4℃ were studied. The results showed that Ca( AsA) 2 treatment delayed Vc content de⁃crease and prevented relative conductivity from increasing. Ca( AsA) 2 treatment could inhibit the activities of polyphenol ox⁃idase (PPO) and peroxidae (POD), decrease the level of total phenol(TP) content, and control the browning of fresh⁃cut iceberg, thereby delaying senescence and keeping better quality. Among the treatments, the concentration of 35 g/L calcium ascorbate treating for 20 min presented the best effect.%以鲜切结球生菜为材料,研究了不同抗坏血酸钙浓度和浸泡时间对其在4℃货架期间品质的影响。结果表明:抗坏血酸钙处理能够延缓鲜切生菜贮藏期间Vc含量降低,阻止相对电导率增大,同时抑制多酚氧化酶(PPO)和过氧化物酶(POD)活性,减缓总酚(TP)含量增加,延缓衰老,保持较好的质地。其中,35 g/L抗坏血酸钙处理20 min的抑制效果最佳。

  13. Clinical and pathological studies on intoxication in horses from freshly cut Jimson weed (Datura stramonium-contaminated maize intended for ensiling : clinical communication

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    R. Binev

    2006-06-01

    Full Text Available Spontaneous intoxication in 34 horses after ingesting freshly harvested maize that was to be used for ensiling and heavily contaminated with young Datura stramonium plants, is described. The clinical status of all horses was monitored for 7 days, and included body (rectal temperature, respiratory and heart rates, colour and moistness of visible mucosae, changes in pupil size, appetite, thirst, general behaviour, locomotion, sensory perceptions, urination and defaecation. The intoxication was accompanied by altered clinical status, namely mild hyperthermia, tachycardia, polypnoea, dyspnoea and shallow breathing, mydriasis, dry oral, rectal, vaginal and nasal mucosae, acute gastric dilatation and severe intestinal gas accumulation, anorexia to complete refusal of feed, decreased or absent thirst, absence of defaecation and urination. As a result of the treatment, the clinical parameters normalised between days 2 and 5. Necropsies and pathological studies were performed on two horses that died, revealing toxic liver dystrophy, cardiac lesions and substantial dystrophic and necrotic processes in the kidneys. The observed clinical signs, the pathomorphological changes and the applied therapy could be used in the diagnosis, differential diagnosis, prognosis and treatment of Jimson weed intoxication.

  14. 鲜切茄子酶促褐变的过氧化物酶的特性研究%Study on the Characteristics of Enzyme Browning of Peroxidase in Fresh-cut Eggplant

    Institute of Scientific and Technical Information of China (English)

    刘春丽; 陈欲云

    2012-01-01

    鲜切茄子在切片、贮藏和货架销售过程中易发生酶促褐变,从而降低其品质。文章对鲜切茄子褐变的过氧化物酶的酶学特性进行了深入研究。结果表明:茄子皮的过氧化物酶活性略高于茄子肉,过氧化物酶的最适pH为6左右,在pH6~8范围内较稳定;该酶的最适反应温度为40℃左右,对热稳定性较差,90℃加热4 min,过氧化物酶完全失去活性。考察了抗坏血酸、L-半胱氨酸、亚硫酸氢钠对茄子过氧化物酶的抑制作用,其抑制效果依次是抗坏血酸〉L-半胱氨酸〉亚硫酸氢钠。%Enzyme browning is likely to occur in the process of cut,storage and sell of fresh-cut eggplant,which lower the quality of eggplant.The enzymology properties of peroxidase in the browning of fresh-cut eggplant is lucubrated.The results showed the activity of peroxidase of the skin is slightly higher than the flesh and the optimum pH of peroxidase was 6.Peroxidase is stable when the pH ranges from 6 to 8.the The optimum temperature of peroxidase was 40℃ and it is not stable in the heat.Peroxidase lost its activity completely when it was heated at 90℃ for 4 minutes.This paper studied the inhibiting effect of Vc,citric acid and NaHSO3 on the activity of peroxidase of eggplant,and the result was Vccitric acid NaHSO3.

  15. Avaliação da vanilina como agente antimicrobiano em abacaxi 'Pérola' minimamente processado Evaluation of vanillin as an antimicrobial agent on fresh-cut 'Pérola' pineapple

    Directory of Open Access Journals (Sweden)

    Lucimara Rogéria Antoniolli

    2004-09-01

    Full Text Available Procurou-se avaliar os efeitos da vanilina como agente antimicrobiano, bem como o nível de injúria física como fator de contaminação inicial em abacaxi (Ananas comosus (L. Meer cv. Pérola minimamente processado. Fatias e cubos foram obtidos a partir de frutos sanitizados, descascados e fatiados mecanicamente. Os dois tipos de corte foram imersos, separadamente, em água (controle ou soluções de vanilina 3000 ou 5000mg.L-1, durante 30 segundos. Após período de repouso, para drenagem do excesso de líquido, foram acondicionados em embalagens de polietileno tereftalato e mantidos à temperatura de 4 ± 1°C durante 12 dias. As análises microbiológicas, realizadas em intervalos de 3 dias, envolveram a contagem de microrganismos aeróbios mesófilos e de bolores e leveduras e a determinação de coliformes totais e fecais. A utilização de vanilina mostrou-se ineficiente no controle do crescimento da população de microrganismos aeróbios mesófilos e de bolores e leveduras em abacaxi 'Pérola' minimamente processado. O maior nível de injúrias físicas efetuado nos cubos parece favorecer a contaminação inicial do produto.The purpose of this research was to evaluate the effects of vanillin as an antimicrobial agent, as well as the relationship between the injury degree and initial contamination in fresh-cut pineapple (Ananas comosus (L. Meer cv. Pérola. Slices and cubes were obtained from whole fruits that were mechanically peeled and sliced after sanitization. Both kinds of cutting were dipped in pure water (control or vanillin solutions 3000 or 5000mg.L-1, for 30 seconds. After that, the liquid was drained, slices and cubes were placed in polyethylene terephtalate packages and stored at 4 ± 1°C during 12 days. Microbiological analyses were carried out every 3 days and involved mesophile aerobic counts, molds and yeasts and total and fecal coliforms determination. The use of vanillin was inefficient for the control of mesophile

  16. Separation and Identification of the Dominant Spoilage Microorganism in Film Packaged Fresh-cut Vegetables%膜包装鲜切蔬菜中主要腐败菌的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    陈湘宁; 钟思琼; 金文斌; 张继荣; 孟令川; 刘慧

    2012-01-01

    The film packaged fresh-cut vegetables including carrot and purple cabbage and broccoli are the research object in this paper. In order to identify the dominant spoilage microorganism and analyze the influence of different source and storage temperature on the number of dominant spoilage microorganism during storage. Taking the plate counting method to calculate the total number of colonies of bacteria, yeast and mould which lead to spoilage and identify the dominant species by tiny biochemical reaction. The results show that: bacteria is the main pollution microorganism; different samples of carrot make significant difference on the total number of colonies (P0.05). The storage temperature has big influence on the number of microorganism, low temperature can restrain the growth of microorganism. The dominant spoilage microorganism in carrot is Stenortrophomonas maltophilia, its number of colonies take 69%-75% in finished product and 59% in self-made fresh-cut vegetables; the dominant spoilage microorganism in purple cabbage is Pseudomonas corrugate, its' number of colonies take 66%-70% in finished product and 62% in self-made fresh-cut vegetables; the dominant spoilage microorganism in broccoli is Pseudomonas corrugate, its number of colonies take 72%-77% in finished product and 70% in self-made fresh-cut vegetables. The dominant spoilage microorganisms in those fresh-cut vegetables are p9ychrophilic bacteria.%以胡萝卜、紫甘蓝和西兰花膜包装鲜切菜为研究对象,分析3种鲜切莱贮藏期间的主要腐败菌类,探讨不同样品来源和贮藏温度对主要腐败菌数量的影响.采用标准平板活菌计数法,对引起鲜切菜腐败的主要细菌、酵母菌和霉菌的菌落总数进行测定,并利用微量生化反应鉴定技术确定主要腐败菌的种类.研究结果表明,细菌是污染鲜切莱的主要微生物.对于胡萝卜鲜切菜,不同样品来源之间对细菌菌落总数的影响差异显著(P<0.05),

  17. Comparação entre cultivares de carambola para produção de produtos minimamente processados Comparison among cultivars of star fruits for production of fresh-cut

    Directory of Open Access Journals (Sweden)

    Flávia Okushiro Ogassavara

    2009-06-01

    minimamente processados.This work characterized star fruits 'Hart', 'Malasia' and 'Nota 10', to produce fresh-cut. Fruits newly picked were hygienized, stored for l2 hours at 12± 1ºC and 90 ± 5%RH, processed and the product was packaged in PET packages, and stored at 10.3 ± 1ºC and 80 ± 5%RH during 8 days. The fruit yield for fresh-cut production was evaluated, as well as its quality evolution every 2 days, for weight loss, appearance, rotten occurrence, colour, pH, titratable acidity contents (TA, soluble solids (SS, ascorbic acid (AA and ratio SS/TA. Fresh-cut yield was lower for 'Hart' (44.70%, intermediate for 'Nota 10' (66.38% and higher for 'Malasia' (72.58%. The weight loss, during the storage, was significantly greater on 'Hart' products, when compared to other cultivars. The appearance of products produced from 'Malasia' fruit kept good up to 6 days (level 3, when they showed themselves with marks of darkness; while that one produced with 'Harts' and 'Nota 10' kept good appearance for 4 days (level 3. The colour of the products changed from greenish to green-yellowish, as can it be showed for medium hue value, from 115.40 to 110.48. Soluble solids content of fresh-cut from 'Malasia' (7.26ºBrix and 'Hart' (6.97ºBrix did not vary significantly, and it was lower for 'Nota 10', 8.8ºBrix to 7.1ºBrix. Titratable acidity and pH (3.80 - 3.90 did not vary for 'Malasia' and 'Hart' products, leading to an unchangeable ratio. Ascorbic acid content of three cultivars presented an increase followed by a reduction during the storage period. The results indicated that 'Malasia' fruits were the better than Hart and Nota 10 cultivars for fresh-cut production.

  18. Biocontrole de Listeria monocytogenes por Pediococcus acidilactici em couve minimamente processada Biocontrol of Listeria monocytogenes by Pediococcus acidilactici in fresh-cut kale

    Directory of Open Access Journals (Sweden)

    Wanessa Altimiras Costa

    2009-12-01

    Full Text Available Este estudo avaliou um sistema de biocontrole para inibição de Listeria monocytogenes em couve minimamente processada, objetivando sua segurança durante estocagem sob refrigeração e em condições de abuso de temperatura. O potencial inibitório de bactérias láticas tolerantes ao sal e psicrotróficas contaminantes naturais da couve e Lactobacillus plantarum, Lactobacillus delbrueckii ATCC 9649 e Lactobacillus casei CCT 1465 foram avaliadas contra L. monocytogenes. O isolado de couve identificado como P. acidilactici CCA3 inibiu L. monocytogenes a 10 e 15 °C em ágar MRS e foi selecionado como possível agente de biocontrole. O número de L. monocytogenes na couve minimamente processada aumentou 3,7 e 4,7 ciclos logarítmicos a 5 e 10 °C, respectivamente, após 20 dias de armazenamento e 4,6 ciclos logarítmicos após oito dias a 15 °C. Entretanto, quando 10(8 UFC.g-1 de P. acidilactici CCA3 foram inoculados no produto processado, o crescimento de L. monocytogenes reduziu 2,3 ciclos logarítmicos sob temperatura abusiva de 15 °C. A acidez titulável e as características sensoriais da couve não foram alteradas pela presença de CCA3 ao longo do período de vida útil. Estes resultados sugerem o potencial de aplicação dos bioconservantes na couve minimamente processada, que necessitam estar associados à refrigeração e sanitização para garantir segurança.This study evaluated a biological control system for the inhibition of Listeria monocytogenes in minimally processed kale focusing on its freshness under refrigeration and extreme temperatures. The inhibitory potential of salt and cold tolerant lactic bacteria from natural microflora of kale, Lactobacillus delbrueckii ATCC 9649, Lactobacillus plantarum, and Lactobacillus casei CCT 1465 strains were evaluated against L. monocytogenes. Pediococcus acidilactici CCA3 isolated from kale exhibited a large inhibition zone of L. monocytogenes at 10 and 15 °C in MRS agar and was

  19. 鲜切雷竹笋冷藏过程中木质化机理的研究%Lignification Mechanism of Fresh-Cut Bamboo Shoots during Cold Storage

    Institute of Scientific and Technical Information of China (English)

    周琦; 陈季旺; 高俊; 蔡广霞; 庞彦卿; 宋光森

    2012-01-01

    The activities of phenylalanine ammonialyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO) and the contents of malondialdehyde (MDA), polyphenol and lignin in fresh-cut bamboo shoots stored at 4 ℃ were measured and the lignification mechanism was explored. The results indicated that the activities of PAL and POD and MDA content tended to increase and then decrease with increasing storage time. PPO activity slowly ascended during the first 6 days, and began to descend on the 15 day, whereas polyphenol content sharply declined during the ftrst 6 days, then slow rose, and began to decline again on the 12th day. Lignin content showed a continuous increase, which was 5%-26% in the bottom, 3%-24% in the middle and 2%-22% in the top. These data suggest that the activities of PAL and POD considerably increase during cold storage, which are the key enzymes in the lignification of fresh-cut bamboo shoots. Moreover, phenolic compounds are involved in the synthesis of lignin by providing precursors. Meanwhile, MDA may also be involved in the lignification of fresh-cut bamboo shoots, which needs further identification. Lignin content gradually decreases from the bottom to the top of bamboo shoots, implying the lignification process proceeds from the bottom to the top.%研究鲜切雷竹笋在4℃冷藏条件下苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)活力及丙二醛(MDA)、多酚、木质素含量的变化规律,探讨其木质化机理。结果显示:在冷藏过程中,PAL、POD活力、MDA含量呈先上升,后下降的趋势;PPO活力在前6d缓慢上升,第15天开始下降;多酚含量在冷藏前6d急剧下降,后缓慢上升,第12天又开始下降;木质素含量不断增加,基部为5%~26%,中部为3%~24%,尖部为2%~22%。结果表明:在冷藏期内,PAL、POD活力:赶幅度增加,是导致鲜切雷竹笋木质化的关键酶;酚类物质

  20. Assessment of the Prevalence of Extended-Spectrum β-Lactamase-Producing Enterobacteriaceae in Ready-to-Eat Salads, Fresh-Cut Fruit, and Sprouts from the Swiss Market.

    Science.gov (United States)

    Nüesch-Inderbinen, Magdalena; Zurfluh, Kathrin; Peterhans, Sophie; Hächler, Herbert; Stephan, Roger

    2015-06-01

    Ready-to-eat (RTE) prepacked salads and fruit have been successfully marketed for the last decade in Switzerland and are increasingly important as a component of everyday diets. To determine whether extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are present in RTE salads, fresh-cut fruit, and sprouts on the Swiss market, samples of 238 mixed and unmixed RTE produce from a large production plant and 23 sprout samples from two sprout farms were analyzed. Further, four samples from the production plant's recycled wash water, which is used for crop irrigation, were analyzed. Twelve (5%) of the 238 RTE products and one of the recycled wash water samples yielded ESBL-producing Enterobacteriaceae. Strain identification and PCR analysis of the blaESBL genes revealed Kluyvera ascorbata isolated from a tomato sample harboring a blaCTX-M-2-like gene; multidrug-resistant (MDR) Enterobacter cloacae detected in a chives sample imported from Spain harboring the clinically important bla(CTX-M-15) gene; and 10 Serratia spp. isolated from mixed salads (bla(FONA-2) and bla(FONA-2)-like genes were found in 6 [60%] and bla(FONA-4)-like and bla(FONA-5)-like genes were each found in 2 [20%] of the isolates). The recycled wash water sample tested positive for one extraintestinal pathogenic MDR Escherichia coli B2:ST131 harboring bla(CTX-M-27) and for one MDR E. coli A:ST88 containing bla(CTX-M-3). None of the sprout samples tested positive for ESBL-producing Enterobacteriaceae. Overall, the majority of the Enterobacteriaceae detected in Swiss RTE produce were environmental strains producing minor ESBLs. The detection of an isolate producing a clinically important ESBL in a single sample and of an international circulating pathogenic strain (B2:ST131) in recycled wash water highlights the importance of surveillance of fresh produce and of recycled wash water that will be reused for irrigation purposes.

  1. 丁香、大黄中草药保鲜剂对康乃馨鲜切花保鲜效果的应用研究%Preservative effect of cloves and rhubarb formula on fresh cut carnation

    Institute of Scientific and Technical Information of China (English)

    童红梅

    2013-01-01

    以康乃馨鲜切花‘黄莺’‘凯旋’为试验材料,选用95%乙醇超声波提取丁香、大黄等10种市售中草药中的抑菌成分,通过对致病菌黑曲霉、灰绿青霉的抑菌试验筛选适宜康乃馨鲜切花‘黄莺’与‘凯旋’保鲜用的中草药配方。结果表明:中草药丁香、大黄的抑菌效果与对照多菌灵相当。以中草药丁香和大黄浸提液、蔗糖、氯化钙、水扬酸4种成分经正交试验筛选出了两种中草药保鲜剂,其中保鲜剂1号对康乃馨‘黄莺’保鲜效果好,而保鲜剂2号更适宜于康乃馨‘凯旋’的保鲜。两种保鲜剂均可延长康乃馨鲜切花寿命6~8 d,保鲜效果显著。%Taking 1 0 kinds of chinese herbal medicine 9 5% ethanol ultrasonic extracts as antibacterial ingredient,the chinese herbal medicine formula to Aspergillusniger and Peniciliumglaucus were screened on fresh cut carnation ‘Hongying’and ‘Kaixuan’.The cloves and rhubarb formula showed the same anti-bacterial effect as carbendazim.The 2 kinds of chinese herbal medicine preservative formula were screened by orthogonal test.No.1 preservative had better effect to ‘Huangying’carnation,while No.2 preservative was suitable to ‘Kaixuan’carnation.Both No.1 preservative and No.2 preservative could prolong life of fresh cut carnation 6 to 8 days and showed a good preservative effect.

  2. 酸性电解水对鲜切马铃薯酶促褐变抑制效果研究%Inhibition effects of enzymatic browning in fresh-cut potatoes by using acidic electrolyzed oxidizing water

    Institute of Scientific and Technical Information of China (English)

    邓清云; 刘海杰; 张芊

    2012-01-01

    This investigation was conducted to determine the effect that acidic electrolyzed oxidizing water (AEOW) inhibit enzymatic browning in fresh-cut potato slices and which factors affected its efficiency. Through the comparison of several treatments on △L% values of fresh-cut potato slices after different storage time, the results showed that compared to no treatment, AEOW could significantly (P〈0.05) inhibit the enzymatic browning of potato slices and its effect was equal to oxalic acid (20 mg/L) and citric acid (20 mg/L). This study also found that processing time, the temperature of AEOW, processing methods (soaking, flushing, oscillating) would influenced the effect of AEOW on enzymatic browning, besides the volume of AEOW. When the processing time was 15 min, AEOW was 40 ℃, and the processing method was oscillating, AEOW had a better inhibition effect on browning. Also the speed of oscillating was higher, the effect was better.%研究了酸性电解水对鲜切马铃薯酶促褐变的抑制效果,并进一步探究了影响酸性电解水抑制酶促褐变效果的外因。通过比较几种方式处理的马铃薯切片在不同贮藏期的褐变度,结果表明,与无处理相比,340e指标的酸性电解水均能够显著(P〈0.05)抑制鲜切马铃薯的酶促褐变,其抑制效果与草酸(20mg/L)、柠檬酸(20mg/L)相当。同时研究发现,处理时间、酸性电解水的温度、处理方式(静止浸泡、流水冲洗、振荡)对酸性电解水的褐变抑制效果均产生影响,而料液比变化对酸性电解水的褐变抑制效果影响不大。处理时间为15min,酸性电解水温度为40℃,振荡处理酸性电解水的褐变抑制效果好,且振荡速度越大,效果越好。

  3. 草酸与柠檬酸抑制鲜切香蕉酶褐变的比较研究%Study on inhibition of enzymatic browning of fresh-cut banana by oxalic acid and citric acid

    Institute of Scientific and Technical Information of China (English)

    覃海元; 杨昌鹏; 陈智理; 黄卫萍; 潘嫣丽

    2011-01-01

    The effectiveness of oxalic acid and citric acid in enzymatic browning inhibition of fresh-cut banana slices were studied.At the first experiment, banana slices were dipped in 0,5,10,20,40,60,80,100mmol/L oxalic acid solution and citric acid solution for 5min, respectively, and then stored at room temperature for 8h.The L * values of banana slices were measured every two hours.At the second experiment, banana slices were dipped in 60mmol/L oxalic acid solution and citric acid solution with or without 0.5% sodium isoascorbate for 5min, respectively,packaged in plastic trays covered with PE film, and then stored at 10℃ for 5ad.The L * values of banana slices were measured every day.The results showed that both oxalic acid and citric acid could inhibit browning of fresh-cut banana effectively, but oxalic acid had better anti- browning effectiveness than citric acid, no matter at room temperature or at low temperature.%对草酸和柠檬酸抑制鲜切香蕉片酶褐变的效果进行了研究.鲜切香蕉片分别用0、5、10、20、40、60、80、100mmol/L的草酸和柠檬酸溶液浸泡5 min,然后置于白纸上常温存放8h,每2h抽样测定香蕉片的L*值;鲜切香蕉片分别用60mmol/L草酸,60mmol/L柠檬酸、60mmol/L草酸+0.5%异杭坏血酸钠和60mmol/L柠檬酸+0.5%异抗坏血酸钠溶液浸泡5min,然后装在塑料托盘里,用PE保鲜膜包扎,在10℃下贮藏5d,每天抽样测定香蕉片的L*值.结果表明,无论常温还是低温下,草酸和柠檬酸均可有效抑制鲜切香蕉褐变,而且草酸抑制鲜切香蕉褐变的效果均好于柠檬酸.

  4. Effects of Nano-SiOx/Chitosan Complex (NSCC) on the Shelf Life and Quality of Fresh-cut Chinese Water Chestnut%纳米SiOx/壳聚糖复合物对鲜切荸荠品质和生理的影响

    Institute of Scientific and Technical Information of China (English)

    徐庭巧; 罗自生; 解静

    2011-01-01

    为了探讨纳米SiOx/壳聚糖复合物(NSCC)涂膜处理对鲜切荸荠的保鲜效果,研究10℃条件下1%NSCC涂膜处理对鲜切荸荠品质和生理的影响.结果表明:NSCC可以有效延缓荸荠在贮藏过程中失水率的增加和L值的下降,对硬度和可溶性固形物含量则无显著影响,但可抑制PAL、PPO、POD的活性,延缓总酚含量和褐变指数的增加,延长鲜切荸荠的货架期.这表明1% NSCC能有效保持鲜切荸荠的品质,延缓鲜切荸荠的生理变化,显示其在鲜切荸荠保鲜上有潜在的应用价值.%In order to determine the effectiveness of nano-SiOx/chitosan complex (NSCC) coating on fresh cut Chinese water chestnut stored at 10 ℃ for 5 days, and the effect of 1% NSCC coating on quality and physiology of fresh cut Chinese water chestnut were investigated. The results indicated the weight loss and L value of fresh cut Chinese water chestnut treated by 1% NSCC coating was inhibited, while the effect on firmness and total soluble solid content were not significant. It also inhibited the phenylalanine ammonia lyase(PAL), polyphenol oxidase(PPO) and peroxidase (POD) activities, maintained lower level of BI and total phenolic content and prolonged shelf-life. The present findings suggested that NSCC treatment can maintain quality and inhibit physiology of fresh cut Chinese water chestnut, and could be used commercially to preservation in fresh cut Chinese water chestnut during storage.

  5. 六出花切花瓶插生理和保鲜效应研究%Study on Vase-physiological and Fresh-keeping Effect of Cut-flower Alstroemeria

    Institute of Scientific and Technical Information of China (English)

    张瑜瑜; 李晶; 吴旭; 姚丽媛; 华金珠

    2013-01-01

      为了改善六出花的切花品质,延长其市场供应时间,通过对六出花切花在不同处理的瓶插液中的瓶插生理和保鲜技术进行研究,分析了其外观品质(瓶插寿命、花径)、鲜重、水分平衡变化及其内在生理生化变化(花色素苷含量、细胞膜透性、可溶性糖含量、可溶性蛋白质含量、维生素 C 含量)等的动态变化,比较了不同处理的保鲜液对六出花切花的瓶插生理和保鲜效应的影响,从而筛选出最适合六出花切花保鲜的瓶插液.结果表明:在瓶插保鲜试验中,以200 mg・L-18-羟基喹啉柠檬酸盐+5%蔗糖混合液的保鲜效果最好.与对照比较,该保鲜液可延长切花寿命9 d ;达盛开期晚3 d ;到瓶插的第21天,增加鲜重比对照多24 g 、水分平衡值高1.9 g ;在瓶插后期的第21天,花色素苷含量比对照少约0.5685(吸光值);在细胞膜透性变化方面,瓶插后期的第21天,导电率为73.4%,比对照少22.8%;其可溶性糖含量的最大值比对照高0.249 g・kg-1;可溶性蛋白质含量比 CK 高约1 mg・g-1;维生素 C 含量比对照高5.07259 mg・kg-1.%In order to improve the quality of cut flowers A lstroemeria ,prolong its market supply time ,the vase-physiological and preservation technology of A lstroemeria in different processed preservations were studied . The dynamic change of exterior qualities (vase-life ,flower diameter) ,fresh weight ,moisture balance changes and interior physiological and biochemical changes (anthocyanidin content ,cell membrane permeability ,soluble sugar content ,soluble protein content ,content of vitamin C )of cut flowers of A lstroemeria were analyzed .The effects on vase-physiological and fresh-keeping of A lstroemeria cut-flowers of the different preservative solu-tion were compared with CK ,so as to screen out the most feasible preservative solution for the cut-flower of A lstroemeria .The results showed that in

  6. Fresh-keeping effect of hydroquinone to cut-flower cultivars of Dianthus caryophyllus 'Master'%对苯二酚对香石竹切花品种“马斯特”的保鲜效应

    Institute of Scientific and Technical Information of China (English)

    王荣华; 郑兴峰; 徐小林; 王红燕

    2012-01-01

    By taking 8-hydroxyquinoline citrate, sucrose as the basic liquid and adding hydroquinone of different concentrations to constitute the antistaling agent, the vase planting test has been conducted. The fresh weight, lift-time and diameter of flower of D. caryophyllus 'Master' were measured, the caudex vessels of the cut flowers were observed with light and scan electron microscopy. The results show that hydroquinone could limit blockage of stem caudex vessels, delay unbalance of water, increase flower diameter, and extend vase life-time of D. caryophyllus; Stem caudex vessel blockage of vase planting D. caryophyllus formed during vase life, and the blockages often were gums or mucilage, and a few of that were rod-shaped bacteria; the xylem vessel blockages is not the only cause to terminate vase life-time of cut flower D. caryophyllus. The most optimum formula of the antistaling agent for D. caryophyllus cut flower is 150 mg/L 8-HQC +2% sucrose+lmmol hydroquinone.%以8-羟基喹啉柠檬酸盐和蔗糖为基础液,添加不同浓度对苯二酚组成保鲜剂,对香石竹切花品种“马斯特”进行瓶插处理.实验测定了切花的鲜重、寿命、花径等指标,同时对切花茎基部导管进行了光镜和电镜观察.结果表明,对苯二酚能延缓香石竹切花茎基部堵塞,延迟水分失衡,增大花径,保持切花鲜艳,延迟切花寿命;香石竹切花茎基部导管在瓶插期间形成堵塞,堵塞物质多为不定型物质如粘液或树胶,少量为定型杆菌;堵塞物质并不是影响香石竹切花寿命的唯一因素;150 mg/L 8-HQC +2%蔗糖+1 mmlo对苯二酚的保鲜剂是香石竹切花保鲜的最优配方.

  7. Atividade respiratória e evolução de etileno em alface crespa minimamente processada armazenada sob duas temperaturas Respiratory activity and ethylene evolution of fresh-cut crisphead lettuce stored under two temperatures

    Directory of Open Access Journals (Sweden)

    Leonora Mansur Mattos

    2008-12-01

    Full Text Available O processamento mínimo de hortaliças envolve operações que ocasionam diversas alterações metabólicas no tecido processado, como elevação da atividade respiratória e evolução de etileno. A respiração é um processo complexo pelo qual reações químicas oxidam compostos orgânicos a dióxido de carbono e água para produção de energia. O aumento na evolução de etileno é, também, de extrema importância e pode ser observado em hortaliças submetidas ao processamento mínimo. No presente trabalho, estudaram-se efeitos fisiológicos desencadeados pelo processamento mínimo de alface (Lactuca sativa L., visando conhecer a melhor temperatura de armazenamento bem como o estresse causado pelo processamento mínimo afeta o produto. Verificou-se que, logo após o processamento mínimo, as taxas respiratórias eram estatisticamente diferentes para os materiais processados a 5 e 10 mm e folha inteira, tanto na temperatura de 5 ºC quanto a 10 ºC. Verificou-se que o armazenamento a 5 ºC reduziu de forma mais rápida o metabolismo respiratório quando se comparou com o armazenamento a 10 ºC. O perfil das curvas de atividade respiratória e evolução de etileno da alface processada a 10 mm foi o mesmo para as duas temperaturas estudadas, diferindo apenas nos valores, que foram mais altos, conforme esperado, para a temperatura de 10 ºC. No armazenamento à temperatura de 5 ºC, pôde-se observar a redução da evolução de etileno para o material processado a 10 mm, mas não para o processado a 5 mm, nas duas primeiras horas após o processamento mínimo. A melhor temperatura para o armazenamento da alface minimamente processada foi de 5 ºC e o produto processado como folha inteira apresentou menor taxa respiratória e elevação de etileno.Fresh-cut technology involves many operations that might cause metabolic alterations in the processed tissue such as increase in respiration rate and ethylene evolution. Respiration is a complex

  8. Uso de misturas químicas para a manutenção da firmeza de banana 'Prata' minimamente processada Use of chemical mixtures for firmness maintenance of fresh-cut 'Silver' banana

    Directory of Open Access Journals (Sweden)

    Eduardo Valério de Barros Vilas Boas

    2009-02-01

    Full Text Available A banana constitui interessante alternativa para compor saladas de frutas. No entanto, possui curta vida de prateleira após o processamento mínimo em razão da rápida perda da firmeza. Neste trabalho, objetivou-se avaliar o efeito da mistura química contendo cloreto de cálcio, ácido ascórbico e L-cisteína e/com o uso de atmosfera modificada ativa (10 kPa CO2 e 2 kPa O2, enfatizando a perda de firmeza sobre a qualidade e vida de prateleira de banana 'Prata' minimamente processada. O conteúdo de pectina solúvel e a % de solubilização aumentaram significativamente ao longo do período de conservação. A perda de firmeza e o aumento das atividades das enzimas poligalacturonase e pectinametilesterase apresentaram uma interação significativa entre os fatores estudados (Tratamento/Tempo. As fatias tratadas com misturas químicas permaneceram com boas características para o consumo por até 3 dias de conservação. Os tratamentos com injeção inicial de gases de forma isolada, ou junto ao tratamento com mistura química, não propiciaram maior retenção da firmeza de banana 'Prata' minimamente processada em relação ao tratamento contendo L-cisteína (1% p/v + ácido ascórbico (1% p/v + cloreto de cálcio (1% p/v na mistura química.Banana constitutes an interesting alternative to make fruit salad. Nevertheless, they have short shelf life after cutting due to the fast loss of firmness. The objective of this work was to evaluate the effect of chemical mixtures containing calcium chloride, ascorbic acid and L-cysteine with the use of active modified atmosphere (10 kPa CO2 and 2 kPa O2, emphasizing the lost of firmness on the quality and shelf life of fresh-cut 'Silver' banana. Soluble pectin content and the percentage of solubilization increased significantly throughout the conservation period. The lost of firmness and the increase of pectinmethylesterase and polygalacturonase activities presented a significant interaction among the

  9. Aroma compounds in fresh cut pomegranate arils.

    Science.gov (United States)

    Little published information exists regarding flavor and aroma compounds in pomegranate (Punica granatum). Although arils have fruity and sweet characteristics, we found no publications describing actual compounds responsible for their typical flavor. Since most commercial usage of pomegranates in...

  10. 鲜切蔬菜加工过程追溯的原料批次混合优化模型构建%Establishment of materials batch mixing optimization model for traceability of fresh-cuts fruits and vegetables processing

    Institute of Scientific and Technical Information of China (English)

    邢斌; 刘学馨; 钱建平; 王健; 吴晓明

    2015-01-01

    为了保障鲜切蔬菜加工企业的产品质量安全,提高鲜切蔬菜生产加工效率,减少加工过程中因原料批次而导致的召回正本增加等问题,提出了一种鲜切蔬菜加工过程追溯的批次混合优化问题的解决方案。该研究通过分析鲜切蔬菜加工的基本工艺流程,根据中小规模鲜切蔬菜加工企业的实际生产需求,研究适用于单原料仓库、单成品仓库的生产加工过程,构建基于企业生产订单和多原料批次的生产加工模型。在模型构建上,综合考虑了加工过程中单个订单不可拆分,以及原料批次选取时应优先选取最近未用完批次原则等企业生产加工管理的实际因素。在此基础上应用遗传算法对订单的加工次序和原料批次的选取次序进行优化。采用北京某鲜切蔬菜加工企业的实际生产数据对模型进行验证,采用平均召回规模及平均出成率作为鲜切蔬菜加工的目标函数。结果表明,通过算法优化后的目标函数值与初始值相比提高了10.5%,能够有效减少平均召回规模并提高产品加工的综合出成率,该模型为中小规模鲜切蔬菜加工企业的原料批次分配及生产流程的优化提供参考。%In order to protect the quality and safety of products of the fresh cut vegetable processing and improve fresh cut vegetable production and processing efficiency, a fresh cut vegetable processing batch mixing optimization model was put forward, which can reduce the recall cost resulted from the mixed batches during the manufacture. The batch-mixing phenomenon of raw materials often occurs during the production process of fresh-cut vegetables. On the other hand, different batches of materials have different properties which will exert some effects on the rate of the production yield. Proper allocation of the materials’ batches will reduce the recall cost of defective products. In order to enhance the ability of

  11. Características sensoriais e microbiológicas de maçãs minimamente processadas recobertas com películas Sensorial and microbiological characteristics of freshly cut apples with edible coating

    Directory of Open Access Journals (Sweden)

    Luciana Cristina Brigatto Fontes

    2007-03-01

    Full Text Available O objetivo do trabalho foi avaliar as características sensoriais e a microbiologia durante armazenamento refrigerado de maçãs da cultivar Royal Gala minimamente processada (MP, tratadas com solução conservadora e películas comestíveis (dextrina, amido de mandioca e alginato de sódio. Maçãs MP tratadas apenas com a solução conservadora destacaram-se por apresentarem características mais próximas de uma maçã natural recém cortada nos parâmetros de aparência, odor e textura. Nos parâmetros de sabor, este tratamento mostrou-se diferenciado da maçã natural em virtude dos ácidos e sais presentes na solução. As maçãs MP com películas de dextrina e fécula de mandioca apresentaram notas semelhantes nos parâmetros avaliados, evidenciando maior umidade e menor escurecimento que o controle. A película de alginato apresentou-se visivelmente mais espessa e com brilho, o que os provadores associaram como sendo de aparência artificial. Quanto ao tempo de armazenamento, as alterações significativas da maioria dos parâmetros sensoriais avaliados manifestaram-se no 5º dia de armazenamento para as maçãs MP do tratamento controle e, principalmente no 9° dia de armazenamento, para os produtos com película. Foi detectada ausência de Salmonella nas maçãs utilizadas no processamento. Não foram detectados coliformes totais e fecais nas maçãs MP durante todo o período de armazenamento estudado.The aim of this work was to evaluate the sensorial and microbiological characteristics during the refrigerated storage of Royal Gala fresh cut (FC apples treated with conservative solution and edible coating (dextrin, cassava starch and sodium alginate. Freshly cut apples treated with a conservative solution are only really close to the natural ones for presenting characteristics similar in parameters of appearance, odor and texture. In the flavor parameters, this treatment revealed a different flavor to the natural one due to acids and

  12. Efeito do hipoclorito de sódio sobre a microbiota de abacaxi 'Pérola' minimamente processado Effect of sodium hypochlorite on the microflora of fresh-cut 'Pérola' pineapple

    Directory of Open Access Journals (Sweden)

    Lucimara Rogéria Antoniolli

    2005-04-01

    Full Text Available Procurou-se determinar a menor concentração eficiente de hipoclorito de sódio (NaOCl para desinfecção da casca, bem como avaliar a necessidade de utilização do mesmo agente sanitizante no banho de imersão da polpa do abacaxi 'Pérola' minimamente processado. Frutos previamente lavados foram desinfectados com NaOCl 100; 150 ou 200mg.L-1, durante 2 minutos. Após aproximadamente 24 horas de armazenamento refrigerado, os frutos foram descascados e fatiados mecanicamente. As fatias foram imersas em solução de NaOCl 20mg.L-1 ou em água (controle, durante 30 segundos. Após período de repouso, para drenagem do excesso de líquido, foram acondicionadas em embalagens de polietileno tereftalato e mantidas à temperatura de 4 ± 1°C, durante 16 dias. As análises microbiológicas, realizadas em intervalos de três dias, foram: coliformes a 35ºC, coliformes a 45ºC, bactérias aeróbias mesófilas e de bolores, e leveduras. Não foram detectados coliformes totais e fecais em nenhum dos tratamentos, durante 16 dias de armazenamento refrigerado. A desinfecção da casca com NaOCl 200mg.L-1, associada à sanitização da polpa do abacaxi com NaOCl 20mg.L-1, proporcionou menores populações de microrganismos aeróbios mesófilos e de bolores, e leveduras, tornando tais operações imprescindíveis na obtenção de produtos minimamente processados que ofereçam garantia de sanidade ao consumidor.The purpose of this research was to determine the smallest effective concentration of sodium hypochlorite (NaOCl for intact fruit disinfection as well as to evaluate the use of the same disinfectant product for sanitization of the fresh-cut 'Pérola' pineapple. Fruits were washed and disinfected with chlorine solutions (100, 150 or 200mg.L-1 for 2 minutes. After approximately 24 hours of cold storage, fruits were mechanically peeled and sliced. Slices were dipped in 20mg.L-1 of chlorine solution or pure water (control, for 30 seconds. After that, the

  13. Qualidade de tangerina 'poncã' minimamente processada, armazenada a 5°c Quality of fresh-cut 'Poncã' Tangerine, stored at 5°C

    Directory of Open Access Journals (Sweden)

    Daniella Moreira Pinto

    2007-08-01

    Full Text Available Com o presente trabalho, objetivou-se analisar o comportamento da Tangerina 'Poncã' minimamente processada armazenada a 5ºC. O experimento foi executado no Laboratório de Pós-Colheita de Frutas e Hortaliças do Departamento de Ciência dos Alimentos da Universidade Federal de Lavras MG. As frutas foram lavadas com detergente neutro e sanificadas com hipoclorito de sódio a 200 ppm por 15 minutos, descascadas, embaladas e resfriadas imediatamente a 5ºC. Foi utilizado um delineamento inteiramente casualizado simples, com 3 repetições e 3 frutas por parcela experimental. A influência de 5 níveis do fator tempo (0, 3, 6, 9 e 12 dias foi avaliada. A qualidade das frutas foi analisada a partir das seguintes variáveis: perda de massa, rendimento em suco, concentração de O2 e CO2 no interior das embalagens, valores L*, a* e b*, pH, acidez titulável, sólidos solúveis, beta-caroteno e vitamina C. A temperatura de 5°C foi adequada no armazenamento de Tangerina 'Poncã' minimamente processada, baseado nas pequenas modificações na cor, acidez titulável, sólidos solúveis, perda de massa e rendimento do suco, embora, perdas nos teores de vitamina C (34,07% e beta-caroteno (42,75% tenham sido observadas.The objective of the work was to analyze the behavior of the fresh-cut 'Poncã' Tangerine stored 5ºC. The experiment was carried out in the Postharvest Fruit and Vegetables Laboratory of the Food Science Department / Federal University of Lavras - Brazil. The fruit were washed with neutral detergent and sanitized with sodium hipochlorite 200ppm for 15 minutes, peeled, packed and immediately cooled at 5ºC. It was used a fully randomly design, with 3 replications and 3 fruits per plote. The influence of 5 levels of the factor time (0, 3, 6, 9 and 12 days was evaluated. The quality of the fruit was analyzed based in the following variable: mass loss, juiciness, concentration of O2 and CO2 into the packages, L *, a* and b * values, p

  14. Quality evaluation of fresh-cut ‘Pérola’ pineapple stored in controlled atmosphere Avaliação da qualidade do abacaxi ‘Pérola’ minimamente processado, armazenado sob atmosfera controlada

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    Lucimara Rogéria Antoniolli

    2007-09-01

    Full Text Available The purpose of this research was to determine the best gas mixture in controlled atmosphere conditions to store fresh-cut ‘Pérola’ pineapple, particularly in relation to the maintenance of visual quality and reduction of microbial growth. After sanitation, fruit was manually peeled, sliced and dipped in 20 mg.L-1 NaOCl solution for 30 seconds. Then, the excess liquid was drained and the slices were placed in sealed glass jars connected to a flowboard installed in a cold room (5 ± 1 °C. Desired gas mixtures were supplied continuously for 12 days from cylinders connected to the flowboard. Controlled atmospheres of 2:5, 2:10, 2:15, 5:5, 5:10, 5:15, 8:5, 8:10 and 8:15 (O2:CO2, % and air were used. The product was evaluated for pulp color, total and fecal coliforms, mesophilic and psychrotrophic aerobic, mold and yeast counts. Total and fecal coliforms were not detected. The fresh-cut ‘Pérola’ pineapple was not very sensitive to storage in controlled atmosphere, considering that the slices had little browning and were free of contamination, that would affect the food safety at the end of the storage periodProcurou-se determinar a composição gasosa ótima para o armazenamento do abacaxi ‘Pérola’ minimamente processado, particularmente com relação à melhoria da qualidade visual e à redução do crescimento microbiano. Frutos previamente sanitizados foram descascados e fatiados manualmente. As fatias foram imersas em solução de NaOCl 20 mg.L-1 durante 30 segundos. Após período de repouso, para drenagem do excesso de líquido, foram acondicionadas em frascos de vidro herméticos conectados a um fluxcentro instalado em câmara refrigerada a 5 ± 1 °C. As composições gasosas desejadas foram fornecidas continuamente, durante 12 dias, a partir de cilindros conectados ao fluxcentro. As combinações de O2:CO2 (%, balanceadas com N2, foram as seguintes: 2:5, 2:10, 2:15, 5:5, 5:10, 5:15, 8:5, 8:10 e 8:15. O tratamento controle foi

  15. Influência de diferentes temperaturas na manutenção da qualidade de Pequi minimamente processado Influence of different temperatures in maintenance of quality of fresh-cut Pequi

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    Clarissa Damiani

    2008-02-01

    Full Text Available Neste trabalho, objetivou-se avaliar o efeito de quatro diferentes temperaturas, 0°C, 5°C, 10°C e 22°C, na qualidade de pequis minimamente processados, durante 15 dias de armazenamento. Os pequis foram lavados, sanificados, seus pirênios extraídos, embalados e armazenados por 15 dias a 0°C e 5°C, 9 dias a 10°C e 3 dias a 22°C. A cada três dias, foram realizadas as análises: taxa respiratória, perda de massa, firmeza, sólidos solúveis, acidez titulável (ácido cítrico, pH, coloração (L* e b* e concentração de O2 e CO2, no interior das embalagens. A taxa respiratória e a perda de massa foram menores quanto menor a temperatura; a firmeza não sofreu variações significativas; os sólidos solúveis sofreram influência somente do tempo, com aumento em seus teores; a acidez titulável aumentou no decorrer do armazenamento, com conseqüente declínio no pH; o valor L* aumentou nos frutos a 0°C e diminuiu naqueles a 22°C; o valor b* decresceu durante o armazenamento e a concentração de gases, no interior das embalagens, teve pouca variação. Pelos resultados, constatou-se que as temperaturas de 0°C e 5°C foram as mais eficazes na manutenção da qualidade de pequis minimamente processados.The objective of the work was to evaluate the effect of four different temperatures, 0°C, 5°C, 10°C and 22°C, on the quality of fresh-cut pequi, during 15 days of storage. The pequi fruit were washed, sanitized, their kernels extracted, packaged and stored for 15 days at 0°C and 5°C, 9 days at 10°C and 3 days at 22°C. The analyses were carried out every three days: respiration rate, mass loss, firmness, soluble solids, titratable acidity (acid citric, pH, coloration (L*and b*value and O2 and CO2 concentrations into the package. The lower temperature the lower respiration rate and mass loss; the firmness did not suffer significant variations; the soluble solids were influenced just by the time, increasing over the storage period

  16. Influência da sanificação sobre a qualidade de melão 'amarelo' minimamente processado: parte II Influence of the sanitation on the quality of the fresh cut yellow melon: part II

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    Helga Parra dos Santos

    2005-10-01

    Full Text Available Visando o melhor aproveitamento, a agregação de valor e a conveniência para o consumo, está sendo empregado o processamento mínimo do melão, colocando no mercado um produto in natura fresco pronto para o consumo. Objetivou-se com esta pesquisa avaliar a qualidade sensorial de melão 'Amarelo' minimamente processado sanificado com peróxido de hidrogênio (H2O2 e dicloro isocianurato de sódio (NaDCC, armazenado a 4 + 1ºC durante 16 dias. Foram realizadas análises de sabor, textura, aparência e cor. Ocorreu redução linear nos valores das notas de sabor e textura ao longo do período de armazenamento. As notas variaram entre 8 (muito boa e 7 (moderadamente boa nos períodos iniciais, reduzindo para 6 (ligeiramente boa e 5 (indiferente ao final do período de armazenamento, não caracterizando a rejeição destes parâmetros por parte dos provadores. O tratamento com H2O2 a 2% teve menor aceitação quanto ao sabor e textura. A aparência e a cor não foram influenciadas pelos tratamentos, mas receberam notas menores ao longo do período de armazenamento. Os valores das notas para aparência e cor se mantiveram em 8 (muito boa até o penúltimo dia, recebendo nota 6 (ligeiramente boa apenas no último dia de armazenamento. De acordo com os resultados obtidos, concluiu-se que o melão 'Amarelo' minimamente processado foi considerado de boa aceitação, não ocorrendo depreciação acentuada na qualidade sensorial. O tratamento com NaDCC 50 ppm obteve melhor aceitação quanto à sabor e textura do que o tratamento com H2O2 a 2%.The goal of this research was to evaluate the sensorial quality of fresh cut 'Yellow' melon, sanitized with hydrogen peroxide (H2O2 and sodium dichloroisocyanurate (NaDCC, stored at 4+ 1ºC for 16 days. Flavor, texture, appearance and color analyses were performed. A linear reduction in the values of the scores of flavor and texture was abserverd along the storage period. The scores ranged between 8 (very good and

  17. Controle do escurecimento enzimático e da firmeza de polpa em pêssegos minimamente processados Control of enzymatic browning and flesh firmness in fresh-cut peaches

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    Amauri Costa da Costa

    2011-06-01

    Full Text Available O escurecimento enzimático e o amolecimento são as principais alterações que podem afetar pêssegos minimamente processados (MP. Objetivou-se avaliar a aplicação de L-cisteína (Cis, ácido L-ascórbico (AA e cloreto de cálcio (CC no controle do escurecimento enzimático e da perda de firmeza de polpa de pêssegos MP, cv. 'Esmeralda'. Os frutos foram processados e, após o fatiamento, imersos nos tratamentos: (I água (controle; (II AA+CC; (III Cis+CC; e, (IV Cis+AA+CC. Em seguida, as fatias foram acondicionadas em embalagens rígidas envoltas com filme PVC de 30µm de espessura e armazenadas durante seis dias a 4±1°C e 85±3% UR. As amostras foram avaliadas quanto aos aspectos físico-químicos, enzimáticos e sensoriais a cada dois dias. O tratamento Cis+AA+CC resultou em maiores valores de L* e h°, o que indica ter sido o mais eficaz na prevenção do escurecimento. Os tratamentos com L-cisteína resultaram em menor atividade da polifenoloxidase (PPO e o tratamento Cis+AA+CC foi o mais efetivo na contenção da atividade da peroxidase (POD, indicando que o melhor desempenho desse tratamento está associado à menor atividade de PPO e POD. A avaliação sensorial indicou que o tratamento Cis+AA+CC foi o mais eficiente, proporcionando a manutenção de características sensoriais aceitáveis aos pêssegos MP, cv. 'Esmeralda'.The enzymatic browning and firmness loss are the major changes that could affect fresh-cut peaches. The objective was to evaluate the application of L-cysteine (Cis, L-ascorbic acid (AA and calcium chloride (CC in the control of browning enzymatic and loss of firmness of minimally processed dried peaches, cv. 'Esmeralda'. The fruits were processed industrially and, after slicing, immersed in treatments: (I water (control; (II AA+CC; (III Cis+CC and (IV Cis+AA+CC. After, the slices were packed in packages sealed with PVC film 30µm thick and stored for six days at 4±1°C and 85±3% UR. The samples were evaluated

  18. 不同涂膜处理对鲜切铁棍山药品质的影响%Effect of Different Film Treatments on the Quality of Fresh-cut Dioscorea opposita Thunb.cv.Tiegun

    Institute of Scientific and Technical Information of China (English)

    庞凌云; 祝美云; 李瑜; 宋思聪

    2011-01-01

    以壳聚糖和海藻酸钠为保鲜剂,对鲜切铁棍山药进行涂膜保鲜,每隔2d测定失重率、Vc含量、可滴定酸含量、褐变度、可溶性固形物含量、多酚氧化酶活性等指标研究保鲜效果。同时以空白组、壳聚糖涂膜组作为对照。结果表明:壳聚糖浓度为1.2%的单一膜和1.2%壳聚糖、0.2%海藻酸钠复合膜都能有效地抑制鲜切铁棍山药的褐变,降低失重率,减少营养物质的损失。复合膜的保鲜效果最好。%Fresh-cut Dioscorea opposita Thunb.cv.Tiegun were coated with edible film composed of chitosan and sodium alginate.Every two days the weight loss rate,Vc content,titratable acid content,browning,soluble solid content,PPO activity were measured to study the preservation effect.The untreated group and chitosan single coating film group were compared.The results showed that the 1.2% chitosan single coating film and 1.2%-chitosan-0.2%-sodium-alginate composite film could effectively reduce the browning,weight loss rate and nutrient loss.The best preservation effects were achieved by compound coating film.

  19. Quality of the fresh cut ‘Orange Flesh’ melon stored under modified atmosphere/ Qualidade do melão ‘Orange Flesh’ minimamente processado armazenado sob atmosfera modificada

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    Leandro Camargo Neves

    2007-08-01

    Full Text Available This work aimed at evaluate the effect of the fresh cut ‘Orange Flesh’ melon stored under modified atmosphere. The cubes of melons were sanitizationed with 100 mg L-1 of hypoclorite of sodium for one minute, washed, drained and wrapped with different concentrations of O2 and CO2 in plastic bags of polyethylene (Nylon Polished. They were appraised every other day for ten days as regards the firmness, total pectin, soluble pectin and activity of the polifenoloxidase and peroxidase. At the end of the conservation period, it was verified that melons sustained the firmest texture of the vegetable products under modified atmosphere, and the concentration of 5%O2 + 3% CO2 showed smaller content of total pectin and together with the concentration of 100% N2 the smallest content of soluble pectin, the polifenoloxidase activity was not verified as well as of the peroxidase.Este trabalho teve como objetivo avaliar o efeito da atmosfera modificada na qualidade do melão‘Orange Flesh’minimamente processado. Os cubos de melões foram sanificados com 100 mg L-1 de hipoclorito de sódio por um minuto, lavados, drenados e embalados com diferentes concentrações de O2 e CO2 em sacos plásticos de polietileno (Nylon Poli. Foram avaliados a cada dois dias durante dez dias quanto a firmeza, pectina total, pectina solúvel e atividade da polifenoloxidase e peroxidase. Ao final do período de conservação, os produtos vegetais com modificação da atmosfera mantiveram a textura mais firme e a concentração de 5%O2 + 3% CO2 apresentaram menor teor de pectina total e juntamente com a concentração de 100% N2 o menor teor de pectina solúvel e não apresentaram atividades de polifenoloxidase e peroxidase.

  20. The Effect of Short-term Storage and the Hot Water Treatment of Fresh-Cut Pepper Fruit cv. ‛Blondy F1’ and ‛Yecla F1’ on the Content of Bioactive Compounds and Antioxidant Properties

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    Szwejda-Grzybowska Justyna I.

    2016-12-01

    Full Text Available The aim of the experiment was to determine the changes in the contents of bioactive compounds and antioxidant/antiradical activity in fresh-cut fruits of sweet pepper cv. ‘Blondy F1’ and ‘Yecla F1’, depending on the postharvest treatment. Treatment with hot water and short-term storage decreased the content of bioactive compounds and antioxidant/antiradical activity of fruit peppers. The treatment with water at 55 °C for 12 sec. of fresh-cut fruits caused lower losses in content of bioactive compounds and antioxidant/antiradical activities than the treatment with water at 45 °C for 10 min. There was a significant correlation between the content of total polyphenols and antioxidant and antiradical activity of pepper fruits depending on the cultivar and the experimental season.

  1. Suitability analysis of fresh-cut vegetable processing for twenty main green capsicum cultivars in China%中国主栽青辣椒品种鲜切加工适宜性评价

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    沈月; 高美须; 杨丽; 赵鑫; 陈雪; 王志东; 李淑荣; 王丽

    2016-01-01

    In order to evaluate the suitability for fresh-cut vegetable processing of green capsicum, 20 main cultivars of green capsicum in China were collected and planted in greenhouse, and fruits were picked at the similar maturity level. Seventeen indices of the fruits were measured, which included physical and chemical indices (L*,a* andb *value, sensory evaluation score, product yield ratio, fruit hardness, pulp thickness, moisture content, ratio of sugar to acid, soluble solids, titratable acid), and functional indices (vitamin C content, total phenolics content, DPPH free radical scavenging activity (DPPH value), ferric ion reducing antioxidant power (FRAP value), ABTS+·radical scavenging activity (ABTS value) and beta carotene content). Significance analysis of basic measured data was carried out by SAS 9.2. Main evaluation indices were filtered by correlation analysis, principal component analysis and variable cluster analysis. The weight of main evaluation indices were determined by analytic hierarchy process (AHP). The suitability for fresh-cut vegetable processing of the 20 tested green pepper cultivars was appraised by grey relational degree analysis method. The basic data of 17 indices on 20 green pepper cultivars were measured and analyzed. Results of significance analysis showed that all indices varied from one tested green capsicum cultivar to another one excepted for moisture content, and the 3 indices which had the top coefficient of variation wereb*value, beta carotene content and FRAP value. Among all the tested 20 cultivars, “Longjiao No. 5” had the highest content of vitamin C, “Jingla No. 2” had the highest content of beta carotene and “Jingyanzhoupila” had the strongest antioxidant capacity. Results of correlation analysis showed that fruit hardness had significantly negative correlation with sensory evaluation score and the correlation coefficient was -0.68, however it had positive correlation with soluble solid content and the

  2. 鲜切果蔬中病原微生物污染及快速检测技术的研究进展%Research progress in rapid detection technology and microbial pathogens infection on fresh-cut fruits and vegetables

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    吕晓萌; 胡文忠; 冯叙桥; 姜爱丽; 郝江燕

    2013-01-01

    鲜切果蔬因具有较高的含水量,再加上较大的切割表面,极易引起病原微生物污染.病原微生物是影响鲜切果蔬安全问题的主要因素之一,在鲜切果蔬上市前对病原微生物进行检测能够保障鲜切果蔬食用的安全性.本文概述了鲜切果蔬中常见的大肠杆菌O157∶H7、沙门氏菌、单增李斯特菌、志贺氏杆菌的生长特点及影响因素等,并介绍了快速检测技术的研究进展及其在鲜切果蔬产业中的应用,包括聚合酶链反应法、酶联免疫法、ATP生物发光法、荧光原位杂交技术、全自动微生物检测系统.%With high moisture content and large cutting surface,fresh-cut fruits and vegetables are easy to cause infection of microbial pathogens.Microbial pathogen is one of the most important factors which effects on the safety of fresh-cut fruits and vegetables.The detection of microbial pathogens can ensure the safety of fresh-cut fruits and vegetables before consuming.In this paper,growth characteristics and influence factors of microbial pathogens on fresh-cut fruits and vegetables were reviewed,including Escherichia coil O157 ∶ H7,salmonella,Listeria monocytogenes,shigella.In addition,research progress of rapid detection were introduced,such as Polynerase Chain Reaction,Enzyme-Linked Immunosorbnent Assay,ATP bioluminescence assay,fluorescence in situ hybridization,automatic microbial detection system as well as in the application on fresh-cut fruits and vegetables industry.

  3. Conservação pós-colheita de espigas de milho verde minimamente processado sob diferentes temperaturas Post-harvest conservation of fresh-cut corn on the cob (Zea maiz L. under different temperatures

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    Alexandra Mara Goulart Nunes Mamede

    2009-02-01

    Full Text Available Objetivou-se, neste trabalho, avaliar o efeito de três temperaturas (5ºC, 8ºC e 11ºC, na qualidade de híbridos de milho verde (Zea maiz L. com endosperma normal, minimamente processado, durante oito dias de armazenamento, com avaliações a cada dois dias. Foram utilizadas espigas de dois híbridos, sendo um comercial da Sementes Agroceres (Ag 1051 e outro do programa de melhoramento da Embrapa Milho e Sorgo (Embrapa HT1. A temperatura de 5ºC foi a que melhor preservou a qualidade das espigas dos híbridos de milho verde estudados, por proporcionar perda de massa reduzida e manutenção dos teores de sólidos solúveis, frutose e glicose. O híbrido Ag 1051 apresentou menor perda de massa, maiores valores de umidade e maior teor de frutose. O Embrapa HT1 apresentou maiores valores iniciais e finais para os teores de sólidos solúveis e maior valor para a coloração b*. O valor L*, que indica quãoclaro e escuro é produto, também diminuiu ao longo do armazenamento, indicando escurecimento das espigas ao longo do armazenamento.This work had the aim of evaluating the effect of three temperatures (5ºC, 8ºC and 11ºC on the quality of fresh-cut corn on the cob (Zea maiz L. with normal endosperm, for 8 days, with analyses taken every two days. Corn on the cob of two hybrids was used, a commercial common type from Sementes Agroceres (Ag 1051 and the other from the breeding program Embrapa Milho e Sorgo (Embrapa HT1. The temperature of 5ºC was more efficient to preserve the quality of normal corn by promoting reduced mass loss and higher contents of soluble solids, fructose and glucose. The hybrid Ag 1051 presented lower mass loss, higher contents of moisture and higher content of fructose. The hybrid Embrapa HT1 presented higher initial and final values for soluble solids and higher b* value. The L* value also decreased along storage, indicating browning of the corns along the storage.

  4. Influência da posição e formato de corte na preferência sensorial de abacaxi 'Pérola' minimamente processado Influence of the position and cut shape in the sensorial preference of fresh-cut 'Pérola' pineapple

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    Lucimara Rogéria Antoniolli

    2005-12-01

    Full Text Available Procurou-se determinar a melhor porção do fruto, quanto aos teores de sólidos solúveis (SS e acidez titulável (AT e sua preferência sensorial, a ser destinada ao processamento mínimo, bem como o formato de corte preferido para a comercialização na forma de minimamente processado. Os frutos foram descascados manualmente, delimitados em 12 seções de 1cm e fatiados, avaliando-se, cada fatia, quanto ao teor de SS e AT. O delineamento experimental foi em blocos casualizados, onde o fator estudado foi a seção do fruto, com quatro repetições. Os dados foram submetidos à análise de variância e as médias, comparadas pelo teste de Tukey. Sensorialmente, avaliou-se a porção do fruto de maior preferência, utilizando-se, para tanto, do teste de "Ordenação-Preferência". Os resultados foram analisados pelo teste não-paramétrico de Friedman. Os frutos foram ainda avaliados quanto ao formato de corte preferido, através do teste de "Preferência-Pareada". Considerando os teores de SS e AT, não haveria restrições quanto à total utilização do fruto; no entanto, sensorialmente, a porção delimitada pelos 3 centímetros apicais foi pouco aceita, sugerindo que a porção compreendida entre a 4ª e a 12ª seções seja preferencialmente utilizada no processamento mínimo. O corte do abacaxi no formato de fatias foi preferido ao formato em cubos.The purpose of this research was to determine the best portion of pineapple fruit to be used as fresh-cut considering soluble solids (SS, titratable acidity (TA content and preference, as well as the preferred cut shape for its commercialization. Fruits were manually peeled, delimited in 12 sections of 1cm and sliced. Each slice was evaluated for the SS and TA content. The experimental design was in randomized blocks. The studied factor was the fruit section, with four replicates. The data were submitted to the variance analysis and compared by Tukey's test. The preferred fruit portion was

  5. Effects of Plastic Box Modified Atmosphere Storage on the Antioxidant System of Fresh-cut Fuji Apple%箱式气调贮藏对鲜切富士苹果抗氧化系统的影响

    Institute of Scientific and Technical Information of China (English)

    姜爱丽; 胡文忠; 代喆; 田密霞; 刘程惠

    2011-01-01

    以富士苹果为试材,研究了鲜切富士苹果在5℃的5%O2+5%CO:或5%02+10%CO2箱式气调贮藏条件下抗氧化系统的变化情况。每3d测定1次酶促防御系统的酶活性和非酶促防御系统的抗氧化物质的含量,并测定呼吸速率、腐烂率和褐交情况。结果表明:与对照相比,2种CO2浓度的箱武气调贮藏条件均可启动酶促防御系统,使过氧化物酶(POD)、过氧化氢酶(CAT)和超氧化物歧化酶(SOD)的活性得到提高,同时也加速了非酶促防御系统抗氧化物质的消耗,降低了总酚和Vc含量以及贮藏中后期的还原型谷胱甘肽(GSH)含量。2种浓度的CO2处理可有效减慢呼吸速率,抑制腐烂的发生并有效降低褐变程度,其中5%0:+5%CO2更有利于鲜切富士苹果褐交的控制,而5%0,+10%CO2更有利于抑制腐烂。%In order to determine the effects of plastic box modified atmosphere storage on the antioxidant system of fresh-cut Fuji apple, the condition of 5% 02 +5% C02 and 5% 02 + 10% CO= atmosphere at 5℃ were established in this experiment. Meanwhile, the activity of enzymatic defense system, the concentration of non - enzyme antioxidants as well as respiration rate, rot rate and browning degree were measured every 3 d. The results indicated that two kinds of plastic box modified atmosphere with high CO2 were all able to start the enzymatic defense system. There- fore, not only the peroxidase (POD), catalase (CAT) and superoxide dismutase (SOD) activities were increased, but the consumption of antioxidant in non-enzymatic defense system were also accelerate. The total phenolics, Vc and reduced glutathione (GSH) content were decreased. Moreover, 5 % 02 + 5 % CO2 and 5 % 02 +10 % C02 effectively slowed down the respiration rate, inhibited the occurrence of decay and reduced the degree of browning. Apples stored with 5 % 02 +5 % CO2 was better in

  6. Revestimento ativo de amido na conservação pós-colheita de pera Williams minimamente processada Starch-based edible coating on extending shelf life of fresh-cut pear

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    Diego Alvarenga Botrel

    2010-08-01

    significantly more firms (P<0,05 compared to treatments C and T1. Cysteine action over enzymatic browning inhibition was observed in treatments T2 and T3 which do not differed significantly each other (P≥0,05 to ∆E values however these were significantly lower than control (C. At time 6, decimal reduction on psychrotrophs counting reached 3,03 and 2,43 to T3 e T2 compared to control. Enterobacteriaceae counting showed similar behavior where the reduction values were 3,16 and 3,05 to T2 e T3 compared to control. It was verified that using the studied edible coating on fresh cut pear can extend its shelf life.

  7. Qualidade de produto minimamente processado à base de abóbora, cenoura, chuchu e mandioquinha-salsa Maintenance of the quality of fresh-cut products made up of pumpkin, carrot, chayote, and arracacha (peruvian carrot

    Directory of Open Access Journals (Sweden)

    Juliana Alvarenga Alves

    2010-09-01

    Full Text Available O objetivo deste trabalho foi avaliar a qualidade de produto minimamente processado, à base de quatro hortaliças - abóbora, cenoura, chuchu e mandioquinha-salsa, armazenado a 5 ºC por 8 dias. Observou-se que os teores de umidade, fibra, proteína, cinza e fração glicídica das quatro hortaliças não foram afetados pelo tempo de armazenamento, entretanto o teor de extrato etéreo aumentou. Durante o armazenamento, o teor de vitamina C e de acidez titulável diminuiu em todas as hortaliças. O teor de β-caroteno do chuchu não alterou, entretanto, aumentou na abóbora, na cenoura e na mandioquinha-salsa. O pH das quatro hortaliças aumentou com o armazenamento. Os teores de sólidos solúveis da cenoura e da mandioquinha-salsa aumentaram, não sendo afetados na abóbora e no chuchu. As notas de aparência do "mix" não foram inferiores a 7 (gostei moderadamente, durante o armazenamento. Os coliformes a 35 ºC presentes no "mix" aumentaram e não foi constatada a presença de coliformes a 45 ºC e Salmonella sp. em nenhum tempo avaliado. Conclui-se que a vida útil, entendida sob os aspectos nutricionais, sensoriais e microbiológicos, pode ser estabelecida em 8 dias sob refrigeração para abóbora, cenoura, chuchu e mandioquinha-salsa submetidos ao processamento mínimo.The goal of this study was to evaluate the quality of fresh-cut products made up of four vegetables: pumpkin, carrot, chayote, and arracacha (peruvian carrot stored at 5 ºC for 8 days. It was observed that the contents of humidity, fiber, protein, ash, and glucidic fraction of the four vegetables were not affected by the time of storage; however, the content of ethereal extract increased. During storage, the content of vitamin C and titratable acidity decreased in all the vegetables. The content of β-carotene of chayote did not change, whereas the content in the pumpkin, carrot, and the peruvian carrot increased. The pH of the four vegetables increased during storage

  8. 壳聚糖植酸天然复合涂膜对鲜切莲藕保鲜效果的研究%Study of Natural Film with Chitosan Combining Phytic Acids on Preservation of Fresh-cutting Lotus Root

    Institute of Scientific and Technical Information of China (English)

    于有伟; 李惠; 邸金花; 任引哲

    2012-01-01

    Using chitosan, phytic acid and their combination to film fresh-cutting lotus root, the effect of different film on preservation was studied. Hie result showed that compound film with 1% chitosan and 1% phytic acid could an reduce the weight loss rate and MDA content of fresh-cutting lotus root, postpone browning, restrain the activities of POD, PPO and PAL, and keep the content of vitamin C and polyphenol at relatively high level. At the 8 th day, the weight loss rate of fresh-cutting lotus root with compound film was one half of control, MDA content was lower 18.8% and L value was higher 51.2% than control. Compound film with chitosan and phytic acid is a simple but effective method to preserve fresh-cutting lotus root, which is superior to single chitosan or phytic acid%采用1%壳聚糖、1%植酸和壳聚糖植酸复合涂膜处理鲜切莲藕,研究不同处理对鲜切莲藕贮存效果的影响.研究结果表明,复合涂膜处理能够降低鲜切莲藕的失重率和MDA含量,延缓藕片的褐变,抑制POD、PPO、PAL的活性,同时使维生素C和多酚含量维持在较高水平.贮存至第8天,复合涂膜的鲜切莲藕失重率为对照的1/2,MDA含量比对照低18.8%,L值比对照高51.2%.壳聚糖植酸复合涂膜是一种简便有效的贮存鲜切莲藕的方法,效果优于壳聚糖或植酸单一处理.

  9. Fresh cut yellow melon (CAC submitted to different type cuts and concentrations of calcion chloride stored under modified passive atmosphereMelão amarelo (CAC minimamente processado submetido a diferentes cortes e concentrações de cloreto de cálcio armazenado em atmosfera modificada passiva

    Directory of Open Access Journals (Sweden)

    Rogério Lopes Vieites

    2012-04-01

    Full Text Available The aim of this work was to evaluate the quality of yellow melon inodorus Valenciano Amarelo (CAC fresh cut submitted to two cut types and with application postharvest of calcium chloride. After preparation cubes and slices melon were immersed in solution with different calcium chloride (CaCl2 concentrations for two minutes, afterwards they were conditioned in trays of expanded polystyrene (EPS, covered by plastic film of low density polyethylene (PEBD, stored in cold camera to 5°C ±1 and analyzed for 8 days. They were evaluated pH, firmness, tritable acidity (AT, soluble solids (SS sugar reducer and ratio. The pH values varied from 5.27 to 5.68. The sugars reducers content and the ratio were superior in the slices compared to the cubes. The melon slices maintained larger firmness values compared to the cubes and in general there was reduction in the values of this parameter along the storage period for all treatments. Concentrations of 1.0 and 1.5% of CaCl2, result in larger values of firmness. The storage temperature and modified passive atmosphere they contributed to quality maintenance of MP melon. Concentrations of up to 1.0% of CaCl2 they could be recommended to maintain the melon quality MP melon yellow inodorus (CAC.Objetivou-se neste trabalho avaliar a qualidade de melão amarelo inodorus (cultivar Valenciano Amarelo CAC minimamente processado (MP submetido a dois tipos de corte e com aplicação pós-colheita de cloreto de cálcio. Após preparo cubos e fatias de melão foram imersos em solução com diferentes concentrações de cloreto de cálcio (CaCl2 por dois minutos, sendo em seguida acondicionados em bandejas de poliestireno expandido (EPS, revestidas por filme plástico de polietileno de baixa densidade (PEBD, armazenados em câmara fria a 5°C ±1 e analisadas durante 8 dias. Foram avaliados pH, firmeza, acidez titulável (AT, sólidos solúveis (SS, açúcar redutor e ratio. Os valores de pH variaram de 5,27 a 5,68. O teor

  10. Efeito de revestimentos comestíveis na conservação de mamões minimamente processados Effect of edible coatings on the preservation of fresh cut papayas

    Directory of Open Access Journals (Sweden)

    Juliana Moreno Trigo

    2012-06-01

    Full Text Available Avaliou-se o efeito de revestimentos à base de carboidratos nas características microbiológicas, físicas, físico-químicas e sensoriais de mamão Formosa minimamente processado (MP, armazenado sob refrigeração. Após tratamento com cloreto de cálcio, os frutos descascados e cortados foram imersos em soluções de amido de arroz (AA 3%; alginato de sódio (AS 0,5%; carboximetilcelulose (CMC 0,25%, e armazenados a 5 ºC e 90% de UR. Os produtos foram avaliados nos dias 1, 3, 6, 9, 12 e 15. O uso de revestimentos à base de AA, AS e CMC em mamões MP resultou em menor contagem de coliformes totais que o controle. Mamões revestidos com AA e CMC apresentaram redução e aumento do processo respiratório, respectivamente. Os frutos revestidos apresentaram menores teores de sólidos solúveis e seus valores de pH se tornaram menores após o 9º dia de armazenamento. O uso da CMC como revestimento proporcionou, no 15º dia, maior firmeza da polpa. As variações nos parâmetros de cor (Luminosidade, Hue e Croma não comprometeram a qualidade sensorial do mamão MP. Os atributos sensoriais dos mamões com revestimentos não diferiram do controle durante os 15 dias de estudo. Como a maioria dos efeitos positivos das coberturas ocorreu aos 12º e 15º dias e, considerando-se o custo da tecnologia e o preço dos revestimentos, a melhor opção, até 9 dias de armazenamento, consiste em apenas sanitizar os frutos, como feito no controle. Se o interesse for preservar a vida útil por um período maior, até 15 dias, os revestimentos utilizados podem ter resultados satisfatórios, desde que respeitadas as condições de estocagem utilizadas no estudo.The experiment evaluated the effects of carbohydrate-based coatings on the microbiological, physical, physical-chemical and sensory properties of the fresh cut (FC Formosa papaya stored under refrigeration. After treatment with calcium chloride, peeled and sliced portions of the fruit were immersed in 3

  11. Avaliação de diferentes sanificantes na qualidade microbiológica de mandioquinha-salsa minimamente processada Evaluation of different sanitizers on the microbiological quality of fresh-cut peruvian carrot

    Directory of Open Access Journals (Sweden)

    Elisângela Elena Nunes

    2010-08-01

    were utilized. Detergent and water were used for the surface cleaning of the roots. Afterwards, the roots were divided into two groups: control (not sanitized and sanitized, for immersion into 100mg.L-1 sodium dichloro isocyanurate for 15 minutes. They were then peeled, sliced into rings and immersed into the following sanitizers: sodium hypochlorite (25, 50 and 100 mg.L-1 for 10 minutes, hydrogen peroxide (3 and 6%, for 5 minutes and sodium dichloro isocyanurate (50, 100 and 200 mg.L-1 for 10 minutes; packed and stored in cold chamber ( 5 ± 1ºC and 98% RH for 15 days. The following analyses were performed every 3 days: pH, titrable acidity, soluble solids, coliforms determination and search for Salmonella. The pH, AT and SS variables were not affected by the used treatments. The presence of coliforms at 45ºC and Salmonella was not detected during the storage of either control or sanitized fresh-cut Peruvian carrots and low counts for coliforms at 35ºC were found. The sanitization of the produce before processing with 100mg.L-1 sodium dichloro isocyanurate and hygienic-sanitary conditions during processing allow obtaining a produce with microbiological standard according to the food legislation until the 15th day of storage.

  12. Adição de agentes antiescurecimento, antimicrobiano e utilização de diferentes filmes plásticos, em mamão minimamente processado Adition of antibrowning and antimicrobes agents and utilization of different plastic films in fresh cut processing of papaya

    Directory of Open Access Journals (Sweden)

    Álvaro Silva Lima

    2005-04-01

    Full Text Available O mamão é uma fruta climatérica largamente produzida no Brasil que pode ser submetida à aplicação dos procedimentos de processamento mínimo. Neste trabalho, conduziram-se experimentos nos quais foram avaliadas a ação do tipo de embalagem e a aplicação de produtos químicos na manutenção da qualidade físico-química e sensorial da fruta com o tempo de armazenamento. Observou-se que a melhor condução do processamento foi obtida quando se fazia a embalagem com filme de PVC e aplicação de sorbato de potássio (0,75%, p/v, pois não produziu perda da qualidade sensorial ao mamão processado.Papaya is a climateric fruit widely produced in Brazil and can easily be submitted to fresh cut processing. In this work, experiments were conducted to evaluate the action of the type of packing and the application of chemical products in the increase of the sensorial quality of fresh-cut papaya. It was observed that the best conduction of the processing was obtained using PVC film packing and potassium sorbate (0.75%, w/v, because it didn't produce the lost of the sensorial quality.

  13. Effect of ozone water combined with modified atmosphere packaging on preservation of fresh-cut Hang cabbage%臭氧水清洗结合气调包装对鲜切杭白菜保鲜效果的研究

    Institute of Scientific and Technical Information of China (English)

    雷昊; 谢晶; 乔永祥; 张栓栓

    2017-01-01

    以1.8 mg/L臭氧水清洗的鲜切杭白菜为试验材料,研究不同气体组分的气调包装(CK为空气;A为5% O2+5% CO2+90% N2;B为5% O2+10% CO2+85% N2;C为10% O2+5% CO2+85% N2;D为10% O2+10% CO2+80% N2)对鲜切杭白菜保鲜效果的影响.结果表明:B组低氧高二氧化碳的包装能有效地抑制鲜切杭白菜上微生物的生长,保持其较好的感官品质,同时延缓VC、叶绿素及可溶性固形物含量的降低,防止杭白菜过快失水,有效地保证鲜切杭白菜的货架期在15 d以上.%Fresh-cut hang cabbage cleaned by 1.8 mg/L ozone water was selected as the experimental material, the effect of keeping fresh on fresh-cut Hang cabbage was studied by different gas composition modified atmosphere packages, such as CK for air, A for 5% O2+ 5% CO2 +90% N2, B for 5% O2+10% CO2+85% N2, C for 10% O2+5% CO2+85% N2, D for 10% O2+10% CO2+80% N2.It showed that the 5% O2+10% CO2+85% N2, low oxygen and high carbon dioxide packaging could effectively inhibit the growth of microorganisms, keep good sensory quality, and delayed the decreasing of vitamin C, chlorophyll and soluble solids content, prevented the cabbage excessive water loss, which effectively guaranteed the shelf life of fresh-cut Hang cabbage to more than 15 d.

  14. Effect of Harvest Time and L-Cysteine as an Antioxidant on Flesh Browning of Fresh-Cut Cherimoya (Annona cherimola Mill. Efecto del Momento de Cosecha y L-Cisteína como un Antioxidante en el Pardeamiento de Pulpa de Chirimoya (Annona cherimola Mill. Precortada

    Directory of Open Access Journals (Sweden)

    Reinaldo Campos-Vargas

    2008-09-01

    Full Text Available Browning development is the most important factor limiting the quality of fresh-cut cherimoya (Annona cherimola Mill.. However, there is little information available about its causes and methods of control. The effectiveness of L-cysteine (0.125, 0.25 and 0.5% in fresh-cut cherimoya harvested on two occasions (October and November and stored for 6 and 12 days at 0 °C was studied. In order to understand the biological basis of browning, polyphenol oxidase (PPO enzyme activity and total phenolic content in fresh-cut pieces were measured. Quality measurements and sensory analysis indicated that 0.5% L-cysteine was somewhat effective in reducing browning development, without affecting other quality attributes. In terms of physiological parameters, PPO activity did not show differences between mature (at harvest and ripe fruit (at processing in both harvest times, but cherimoya fruits picked in November presented lower PPO activity than fruit from October. In general, PPO activity and total phenolic content of L-cysteine treated fruits did not show consistent differences with untreated fruit at 6 or 12 days at 0 °C. PPO activity analyses demonstrated that PPO activity was higher in the outer part of cherimoya flesh compared to the middle or inner sector. These results would support the possibility of using L-cysteine as a postharvest treatment to reduce browning development in fresh-cut cherimoya.El desarrollo de pardeamiento es uno de los factores limitantes en la calidad de chirimoya (Annona cherimola Mill. precortada (fresh-cut. No obstante, existe poca información disponible en relación a sus causas y métodos de control en esta fruta. Se estudió la efectividad de L-cisteína (0,125; 0,25 y 0,5% en chirimoya precortada cosechada en dos oportunidades (octubre y noviembre y almacenada por 6 y 12 días a 0 ºC. Con el objetivo de conocer las bases biológicas del pardeamiento, se estudió la actividad de polifenol oxidasa (PPO y contenido de

  15. Effect of methyl jasmonate pre-treatment on quality and antioxidant activity of fresh-cut pitaya fruit%茉莉酸甲酯预处理对鲜切火龙果品质和抗氧化活性的影响

    Institute of Scientific and Technical Information of China (English)

    李晓安; 韩聪; 高梵; 龙清红; 金鹏; 郑永华

    2015-01-01

    目的:研究茉莉酸甲酯(MeJA)预处理对鲜切火龙果在10℃,4 d贮藏期间品质和抗氧化活性的影响。方法完整火龙果先用浓度分别为0、1、10和100μmol/L 的MeJA熏蒸,再进行鲜切处理,测定其贮藏期间的品质和理化指标。结果100μmol/L的MeJA熏蒸处理能最显著地诱导鲜切火龙果贮藏期间总酚、总黄酮等次级代谢产物的积累,提高鲜切火龙果贮藏期间DPPH自由基清除能力。MeJA预处理能有效地促进鲜切火龙果贮藏期间超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽还原酶(GR)等抗氧化酶活性的提高。同时, MeJA预处理抑制了可滴定酸(TA)含量的下降,对可溶性固形物(TSS)、维生素C含量无不良影响。结论100μmol/L的MeJA预处理能较好地保持鲜切火龙果的品质,并有效地提高其抗氧化能力,最终提高鲜切火龙果的营养品质。%Objective To investigate the effects of methyl jasmonate (MeJA) pre-treatment on food quality and antioxidant activity in fresh-cut pitaya (Hylocereus undatus) during storage at 10℃ for up to 4 days. Methods Whole pitaya was pre-treated with 0, 1, 10, and 100μmol/L of MeJA, then was cut into pie-cuts, and its quality and physicochemical indexes during storage were measured.Results MeJA 100μmol/L pre-treatment had the most significant inducement effect on the accumulation of the secondary metabolites such as total phenolics and total flavonoids, and significantly enhanced 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging capacity of fresh-cut pitaya during storage. MeJA pre-treatment could significantly promote the increase of antioxidant enzymes activities such as SOD, CAT and GR. Meanwhile, this pre-treatment inhibited the decrease of titratable acid, and had no bad effect on the total soluble solid and vitamin C. Conclusion The MeJA 100μmol/L pre-treatment has a promising application prospect in food quality maintenance of fresh-cut pitaya and markedly

  16. Inactivation of murine Norovirus-1, coliphage φX174 and Bacteroides fragilis phage B40-8 on surfaces and fresh cut iceberg lettuce by hydrogen peroxide and UV light

    OpenAIRE

    2011-01-01

    In this study, the inactivating properties of liquid hydrogen peroxide (L-H2O2), vaporized hydrogen peroxide (V-H2O2), UV light, and a combination of V-H2O2 and UV light were tested on murine norovirus 1 (MNV-1) and bacteriophages (φX174 and B40-8) as models for human noroviruses. Disinfection of surfaces was examined on stainless steel discs based on European Standard EN 13697 (2001). For fresh-produce decontamination, a mixture of the viruses was inoculated onto shredded iceberg lettuce and...

  17. Cutting assembly

    Science.gov (United States)

    Racki, Daniel J.; Swenson, Clark E.; Bencloski, William A.; Wineman, Arthur L.

    1984-01-01

    A cutting apparatus includes a support table mounted for movement toward and away from a workpiece and carrying a mirror which directs a cutting laser beam onto the workpiece. A carrier is rotatably and pivotally mounted on the support table between the mirror and workpiece and supports a conduit discharging gas toward the point of impingement of the laser beam on the workpiece. Means are provided for rotating the carrier relative to the support table to place the gas discharging conduit in the proper positions for cuts made in different directions on the workpiece.

  18. Bone cutting.

    Science.gov (United States)

    Giraud, J Y; Villemin, S; Darmana, R; Cahuzac, J P; Autefage, A; Morucci, J P

    1991-02-01

    Bone cutting has always been a problem for surgeons because bone is a hard living material, and many osteotomes are still very crude tools. Technical improvement of these surgical tools has first been their motorization. Studies of the bone cutting process have indicated better features for conventional tools. Several non-conventional osteotomes, particularly ultrasonic osteotomes are described. Some studies on the possible use of lasers for bone cutting are also reported. Use of a pressurised water jet is also briefly examined. Despite their advantages, non-conventional tools still require improvement if they are to be used by surgeons.

  19. Research progress in mechanical wounding stimulation signal molecules transduction and defensive reaction for fresh-cut fruits and vegetables%鲜切果蔬机械伤害刺激信号分子转导及防御反应的研究进展

    Institute of Scientific and Technical Information of China (English)

    闫媛媛; 胡文忠; 姜爱丽; 陈晨

    2015-01-01

    鲜切果蔬在加工过程中会使果蔬受到机械损伤,组织结构遭到破坏,极易发生褐变与受到微生物侵染,从而加速果蔬组织的衰老和腐败。机械伤害刺激信号分子的产生、运转、感知、接受和转导,以激活受伤害诱导的防卫基因表达,进而诱发鲜切果蔬整体协调产生防御反应。茉莉酸类、水杨酸、乙烯、脱落酸和系统素信号分子诱导果蔬防御反应可减轻机械损伤对鲜切果蔬品质的影响,能够有效抑制微生物对受伤部位的侵染以及果蔬组织内部的酶促褐变,改善果蔬贮藏品质。本文从机械伤害刺激信号分子茉莉酸类、水杨酸、乙烯、脱落酸和系统素的产生及转导方面综述了鲜切果蔬对机械伤害防御反应机制,并从伤害防御方面介绍了外源施用茉莉酸类、水杨酸和乙烯的作用机制与保鲜效果。%Fresh-cut fruit and vegetables during processing will be subjected to mechanical damage, in which the organization structure is destroyed, and it is easy to become browning and be infected by microbial, as well as the aging and corruption of the organization of fruits and vegetables are accelerated. Mechanical noxious stimulate the production, operation, perception, acceptance and transduction of signaling molecules, to activate the injury-induced defense gene expression, and then induced fresh-cut fruits and vegetables to produce the overall coordination of defense response. Jasmine acid, salicylic acid, ethylene, abscisic acid and system elements signaling molecules to induce defense reactions of fruits and vegetables can reduce the effect of mechanical damage on the quality of fresh-cut fruits and vegetables, and can effectively inhibit microbial infection of injured area and the organization enzymatic browning of fruit and vegetable,whichimprove storage quality of fruits and vegetables. This paper summarized the defensive responds of mechanical wounding and

  20. 纤维素膜降解性能及其在切分蔬菜保鲜中的应用研究%Application of Biodegradable Plastic Packaging Film on Preservation of Fresh-cut Vegetables

    Institute of Scientific and Technical Information of China (English)

    胡云峰; 杨秋月; 宋慧颖; 郭红莲

    2012-01-01

    The degradation of cellulose membrane, and the application of cellulose membrane in fresh vegetables are mainly investigated through studying its permeability, moisture permeability, and preservation. The results show that: 1 ) Different microbial has different degradation rate to cellulose membranes; 2 ) Cellulose packaging film's degradation performance is the best that it can be depredated fully after three days by inoculating Penicillium; 3 ) Cellulose packaging film's permeability is better than plastic film, resulting in the poor effects of green color and anti- browning when preserving fresh vegetables; 4 ) Cellulose membrane has so strong water vapor permeability that it's water retention is worse than the plastic packaging film.%主要研究了纤维素膜的降解性能,并通过其透气性、透湿性和保鲜效果三方面的实验来研究纤维素膜在蔬菜保鲜中的应用.结果表明:1)不同微生物对纤维素膜的降解速度有很大差异;2)纤维素保鲜包装膜降解性能好,采用接种青霉的方法,3天后膜达到全部降解;3)纤维素保鲜包装膜的透气性能优于塑料膜,导致保鲜蔬菜时护绿和防褐变效果差;4)纤维素保鲜包装膜的透湿性能较强,对包装的蔬菜保水性较塑料包装膜差.

  1. Inactivation of murine norovirus 1, coliphage phiX174, and Bacteroides [corrected] fragilis phage B40-8 on surfaces and fresh-cut iceberg lettuce by hydrogen peroxide and UV light.

    Science.gov (United States)

    Li, Dan; Baert, Leen; De Jonghe, Maarten; Van Coillie, Els; Ryckeboer, Jaak; Devlieghere, Frank; Uyttendaele, Mieke

    2011-02-01

    In this study, the inactivating properties of liquid hydrogen peroxide (L-H(2)O(2)), vaporized hydrogen peroxide (V-H(2)O(2)), UV light, and a combination of V-H(2)O(2) and UV light were tested on murine norovirus 1 (MNV-1) and bacteriophages (φX174 and B40-8) as models for human noroviruses. Disinfection of surfaces was examined on stainless steel discs based on European Standard EN 13697 (2001). For fresh-produce decontamination, a mixture of the viruses was inoculated onto shredded iceberg lettuce and treated after overnight incubation at 2°C. According to our results, L-H(2)O(2) (2.1%) was able to inactivate MNV-1 and φX174 on stainless steel discs by approximately 4 log(10) units within 10 min of exposure, whereas for B40-8, 15% of L-H(2)O(2) was needed to obtain a similar reduction in 10 min. Only a marginal reduction (≤1 log(10) unit after 5 min of exposure) by V-H(2)O(2) (2.52%) was achieved for the tested model viruses, although in combination with UV light, a 4-log(10)-unit decrease within 5 min of treatment was observed on stainless steel discs. Similar trends were observed for the decontamination of shredded iceberg lettuce, but the viral decline was reduced. These results demonstrated that both L-H(2)O(2) and a combination of V-H(2)O(2) and UV light can be used for norovirus inactivation on surfaces; V-H(2)O(2) (2.52%) in combination with UV light is promising for decontamination of fresh produce with much less consumption of water and disinfectant.

  2. Inactivation of Murine Norovirus 1, Coliphage φX174, and Bacillus fragilis Phage B40-8 on Surfaces and Fresh-Cut Iceberg Lettuce by Hydrogen Peroxide and UV Light▿

    Science.gov (United States)

    Li, Dan; Baert, Leen; De Jonghe, Maarten; Van Coillie, Els; Ryckeboer, Jaak; Devlieghere, Frank; Uyttendaele, Mieke

    2011-01-01

    In this study, the inactivating properties of liquid hydrogen peroxide (L-H2O2), vaporized hydrogen peroxide (V-H2O2), UV light, and a combination of V-H2O2 and UV light were tested on murine norovirus 1 (MNV-1) and bacteriophages (φX174 and B40-8) as models for human noroviruses. Disinfection of surfaces was examined on stainless steel discs based on European Standard EN 13697 (2001). For fresh-produce decontamination, a mixture of the viruses was inoculated onto shredded iceberg lettuce and treated after overnight incubation at 2°C. According to our results, L-H2O2 (2.1%) was able to inactivate MNV-1 and φX174 on stainless steel discs by approximately 4 log10 units within 10 min of exposure, whereas for B40-8, 15% of L-H2O2 was needed to obtain a similar reduction in 10 min. Only a marginal reduction (≤1 log10 unit after 5 min of exposure) by V-H2O2 (2.52%) was achieved for the tested model viruses, although in combination with UV light, a 4-log10-unit decrease within 5 min of treatment was observed on stainless steel discs. Similar trends were observed for the decontamination of shredded iceberg lettuce, but the viral decline was reduced. These results demonstrated that both L-H2O2 and a combination of V-H2O2 and UV light can be used for norovirus inactivation on surfaces; V-H2O2 (2.52%) in combination with UV light is promising for decontamination of fresh produce with much less consumption of water and disinfectant. PMID:21183630

  3. Fresh fruit: microstructure, texture, and quality

    Science.gov (United States)

    Wood, Delilah F.; Imam, Syed H.; Orts, William J.; Glenn, Gregory M.

    2009-05-01

    Fresh-cut produce has a huge following in today's supermarkets. The trend follows the need to decrease preparation time as well as the desire to follow the current health guidelines for consumption of more whole "heart-healthy" foods. Additionally, consumers are able to enjoy a variety of fresh produce regardless of the local season because produce is now shipped world-wide. However, most fruits decompose rapidly once their natural packaging has been disrupted by cutting. In addition, some intact fruits have limited shelf-life which, in turn, limits shipping and storage. Therefore, a basic understanding of how produce microstructure relates to texture and how microstructure changes as quality deteriorates is needed to ensure the best quality in the both the fresh-cut and the fresh produce markets. Similarities between different types of produce include desiccation intolerance which produces wrinkling of the outer layers, cracking of the cuticle and increased susceptibility to pathogen invasion. Specific examples of fresh produce and their corresponding ripening and storage issues, and degradation are shown in scanning electron micrographs.

  4. Avaliação de índices de firmeza para abacaxi minimamente processado em fatias tratadas com soluções de sais de cálcio Firmness indexes evaluation for fresh-cut sliced pineapple treated with calcium salts solutions

    Directory of Open Access Journals (Sweden)

    Marisa de P. Eduardo

    2008-03-01

    Full Text Available Produtos minimamente processados estão prontos para o consumo imediato e devem apresentar qualidade sensorial semelhante à do produto fresco. Embora a maioria dos estudos seja com hortaliças, constata-se o grande potencial de comercialização de frutas minimamente processadas, principalmente aquelas que oferecem alguma dificuldade para a comercialização ou até mesmo para o preparo, sendo o abacaxi um ótimo exemplo disso. O objetivo deste trabalho foi avaliar o efeito de diferentes sais de cálcio (cloreto, sulfato e lactato, nas concentrações de 1% e 3%, utilizando-se de medidas de pH , sólidos solúveis totais e da firmeza, em fatias de abacaxi minimamente processadas. Dois tipos de ponteiras de penetração (cilíndrica e anel vazador e três índices de firmeza foram utilizados para mensurar a textura, visando a identificar o melhor índice. Os resultados mostraram que os tratamentos com sulfato de cálcio 3% mantiveram o índice de firmeza das fatias em até 44,45% superior ao da testemunha. Os índices da ponteira cilíndrica, apesar de apresentarem variabilidade semelhante aos da ponteira de anel vazador, apontaram número maior de diferenças entre a testemunha e os tratamentos.Fresh-cut sliced fruits and vegetables are ready to eat immediately and their sensorial characteristics should be similar to fresh product. Although most of the studies in this area are focused on vegetables, there is a great market potential for fresh-cut sliced fruits, mainly for those which exhibit some commercialization or preparation difficulties such as pineapple. The objective of this work was to evaluate the effect of 1% and 3% concentrations of calcium salts (chloride, sulphate and lactate on pH, total soluble solids and firmness values of minimally processed pineapple slices. Two types of indenters and three firmness indexes were investigated aiming to identify the best index. Results showed that calcium sulphate 3% kept average firmness index

  5. Avaliação da qualidade do caldo extraído de toletes de cana-de-açúcar minimamente processada, armazenados sob diferentes temperaturas Evaluation of the quality of the juice extracted of pieces of fresh cut sugar cane stored under different temperatures

    Directory of Open Access Journals (Sweden)

    Silvana Rodrigues Rabelo de Andrade

    2008-12-01

    Full Text Available O presente trabalho visou avaliar a qualidade físico-química e microbiológica do caldo extraído de toletes de cana-de-açúcar minimamente processada, armazenados sob três temperaturas. Colmos de cana-de-açúcar foram minimamente processados na forma de toletes com 60 cm de comprimento, higienizados e acondicionados em embalagens de polietileno de baixa densidade. Cada embalagem acondicionou 12 toletes de cana-de-açúcar devidamente higienizados. Em seguida, procedeu-se o armazenamento das embalagens sob três temperaturas: ambiente (22 a 25 °C, utilizada como controle, refrigeração (4 °C e congelamento (-20 °C. Foram avaliadas a qualidade físico-química do caldo e a sua composição microbiológica, em intervalos de 6 dias, durante 24 dias de armazenamento. O caldo extraído dos toletes armazenados sob congelamento apresentou boa qualidade físico-química e microbiológica durante todo o período avaliado. Por outro lado, o caldo extraído dos toletes armazenados sob refrigeração e o controle apresentaram elevadas alterações microbiológicas, limitando o período de conservação dos toletes até 12 e 6 dias, respectivamente, o que permitiu concluir que o tratamento mais eficiente para a preservação da qualidade do caldo foi o congelamento da cana-de-açúcar minimamente processada.The present work aimed at evaluating the microbiological and physicochemical quality of fresh cut sugar cane juice. Sugar cane stalks were cut in pieces of 60 cm of length, sanitized, and conditioned in polyethylene packaging of low density. Each package conditioned 12 pieces of sanitized sugar can. After that, they were stored at three different temperatures: room temperature (22-25 °C, used as control, refrigeration (4 °C, and freezing (-20 °C. The microbiological and physicochemical quality of the juice was evaluated every 6 days of storage for 24 days. The sugar cane juice stored under freezing temperatures presented good quality for all

  6. Comparative Study of Cold Storage Effects and Organic Acid Component Contents in Fresh Cut Seeds of Different Pomegranate Varieties%鲜切石榴籽粒冷藏效果及有机酸组分含量比较研究

    Institute of Scientific and Technical Information of China (English)

    杨雪梅; 尹燕雷; 冯立娟; 武冲; 王菲

    2016-01-01

    The fresh cut seeds of pomegranate varieties Taishansanbaitian,Mudan and Sanbaisuan were used as materials.The seeds were sterilized under the UV -lamp for 15 minutes,and then stored at (4 ± 0.5)℃ for 18 days.The freshness -keeping effect,organic acid component contents and antioxidant activity were compared among the 3 varieties.The results showed that the fresh cut seeds of pomegranate varieties Mu-dan and Sanbaisuan owned lower weight loss,rotting rate and relative electrolytic leakage,significantly lower oxalic acid content,significantly higher DPPH free radical scavenging rate and citric acid content,and more stable titratable acid and total soluble solid contents compared with Taishansanbaitian during the cold storage. The main organic acids of the 3 pomegranate varieties all were citric acid,malic acid,oxalic acid and tartaric acid.The malic acid content in pomegranate variety Mudan was significantly lower than that in Sanbaisuan and Taishansanbaitian,while the tartaric acid contents of 3 pomegranate varieties were not significantly different during the storage process.The freshness -keeping effect of the 2 sour pomegranate varieties Mudan and San-baisuan were superior to sweet pomegranate variety Taishansanbaitian.The pomegranate variety Mudan had the most stable organic acid component contents and the best freshness -keeping effect.%以‘泰山三白甜’、‘三白酸’和‘牡丹’石榴成熟期的果实为试材,籽粒经紫外杀菌15 min 后装入保鲜袋于(4±0.5)℃冷藏保鲜18 d,期间比较3个品种籽粒的保鲜品质、有机酸组分含量变化及抗氧化活性。结果表明:2个酸石榴品种籽粒冷藏过程中的失重率、腐烂率、相对电导率均低于甜石榴品种‘泰山三白甜’;而 DPPH 自由基清除率均显著高于‘泰山三白甜’;2个酸石榴品种中可滴定酸和总可溶性固形物含量在整个冷藏期内较稳定,均比‘泰山三白甜’变化幅度小;3个

  7. Cutting Cosmos

    DEFF Research Database (Denmark)

    Mikkelsen, Henrik Hvenegaard

    The foundation for this book is an ethnographic study of masculinity in a Bugkalot village in northern Philippines. While offering new research on the Bugkalot, widely known as the Ilongot, more than 30 years after the last important works were written on this famous hill-people, Cutting Cosmos...... into egalitarian relations. Cutting Cosmos shows how these seemingly opposed characteristics of male life - the egalitarianism and the assertive ideals - are interwoven. Acts of dominance are presented as acts of transgression that are persistently ritualized, contained and isolated as spectacular events within...

  8. Evaluation of different oxygen, carbon dioxide and nitrogen combinations employed to extend the shelf life of fresh-cut collard greens Avaliação de diferentes combinações de oxigênio, gás carbônico e nitrogênio utilizadas no aumento de vida de prateleira de couve minimamente processada

    Directory of Open Access Journals (Sweden)

    Celso L. Moretti

    2003-12-01

    Full Text Available Collard greens (Brassica oleracea var. acephala "Manteiga" were harvested in commercial fields in Brasilia, Brazil, aiming to evaluate different oxygen, carbon dioxide and nitrogen combinations to extend the shelf life of the fresh-cut product. After harvest, leaves were taken to the postharvest laboratory, selected for external blemishes and minimally processed (3 mm thick inside a cold room (13±2°C. After processing, fresh-cut collard greens were stored under two controlled atmosphere (CA conditions (3% O2, 4% CO2; 5% O2, 5% CO2/balance N2, and normal air (control, at 5°C (95±2% RH, for six days. Daily, minimally processed collard greens were evaluated for total vitamin C, total chlorophyll, total soluble solids content, and titratable acidity. Total vitamin C content decreased for all treatments during the storage period. Storage under CA conditions delayed total vitamin C degradation for both atmospheres studied. At the end of the storage period, fresh-cut collard greens stored under 3% O2, 4% CO2 showed around 25% and 56% more vitamin C than the material stored under 5% O2, 5% CO2 and control, respectively. Total chlorophyll content decreased during the storage period. At the end of the experiment, fresh-cut collard greens stored under 3% O2, 4% CO2 showed 24% and 45% more total chlorophyll than the product stored under 5% O2, 5% CO2 and control, respectively. CA storage delayed organic acid degradation. On the sixth day, fresh-cut collard greens stored under 3% O2, 4% CO2 presented around 44% more organic acids than control. Total soluble solids content were not significantly affected.Folhas de couve (Brassica oleracea var. acephala "Manteiga" foram obtidas em campos de produção comercial em Brasília, DF, com o objetivo de avaliar diferentes combinações de oxigênio, dióxido de carbono e nitrogênio para estender a vida de prateleira do produto minimamente processado. Após colhidas, as folhas foram levadas ao laboratório de p

  9. 鲜切雪莲果护色保脆效果的研究%Study on Crisp-protection and Browning Preventing Technology of Fresh-cut Yacon

    Institute of Scientific and Technical Information of China (English)

    刘帅; 邓洁红; 敬小波; 刘永红

    2014-01-01

    Taking fresh yacon as material ,the optimized temperature and time on blanching ,most effective color fixative and hardner were studied .The results showed that ascorbic acid,cysteine and NaCl were all browning inhibitors ,while the ascorbic acid had the best effect on inhibiting the PPO activity .The optimal technology parameters were as follows:The temperature and time on blanching sliced yacon were 70℃and 1min.After washed and drained off,the sliced yacon was soaked in 1% ascorbic acid solution and 0.1%calcium chloride solution successively for 10 min respectively,with the ratio of solid to solution 1∶1.5g/mL.After dried in air,the sliced yacon was packed and stored in 4℃to have ideal color,hardness and fructo-oligose content.%以雪莲果为试材,研究鲜切雪莲片护色保脆工艺,筛选出鲜切雪莲果的最佳热烫温度及时间、最佳护色剂以及硬化剂。结果表明:抗坏血酸、半胱氨酸和氯化钠都有抑制褐变的效果,但抗坏血酸的护色效果最好。最优工艺参数为:雪莲果片经热烫处理(70℃,1min)后,用冷水冲洗沥干,依次浸泡于1%抗坏血酸溶液,0.1%氯化钙溶液各10min,料液比为1∶1.5 g/mL,晾干后将雪莲果片放入保鲜袋中密封,4℃低温贮藏,获得颜色、硬度、低聚果糖含量等指标均理想的雪莲果片。

  10. 响应曲面法优化酸性电解水对鲜切苹果杀菌效果的影响%Response Surface Methodology for Optimization of Sterilization Effect on Fresh-Cut Apple Treated with Acidic Electrolyzed Water

    Institute of Scientific and Technical Information of China (English)

    于晓霞; 李燕; 王婷婷; 宋星

    2015-01-01

    以微生物减菌率为评价指标,在单因素试验的基础上,采用中心组合设计法,研究NaCl质量浓度、处理温度、处理时间,以及料液比对接种金黄色葡萄球菌、大肠杆菌、沙门氏菌和单增细胞李斯特菌的鲜切苹果杀菌效果的影响。响应面分析结果表明,鲜切苹果减菌工艺最优条件为:NaCl质量浓度4.5 g/L,处理温度25℃,处理时间6.45 min,液料比6∶1(mL/g),在此条件下经处理后细菌总数由1.14×105 CFU/g降为9.3×103 CFU/g,减菌率可达91.84%。同时,该处理对鲜切苹果的pH值和可溶性固形物影响不大,且能较好地抑制维生素C的降解及其表面的褐变。%The sterilization effect of acidic electrolyzed water on fresh- cut apple against Staphylococcus aureus, Escherichia coli, salmonella and Listeria monocytogenes cells was studied by response surface methodology and a central composite design with one-factor-at-a-time. Studied variables of NaCl concentration, time, temperature and solid-liquid ratio were selected for the determination of optimal conditions with bactericidal ability evaluated. The optimal conditions were found to be as follows: 6:1 liquid-solid ratio (mL/g) and 4.5 g/L NaCl treated under 25℃for 6.45 min. Under these conditions, the total bacteria count was reduced from 1.14 × 105 CFU/g to 9.3 × 103 CFU/g and the reduction rate of bacteria was up to 91.84%. Moreover, this treatment slightly affected the pH value and the soluble solid contents of fresh-cut apples, while effectively inhibited the degradation of vitamin c and provided surface browning control.

  11. Redução do amaciamento de banana 'Maçã' minimamente processada pelo uso de tratamentos químicos Softening reduction of fresh-cut 'apple' banana by using of chemical treatments

    Directory of Open Access Journals (Sweden)

    Anderson Adriano Martins Melo

    2007-06-01

    Full Text Available O uso de banana em saladas de frutas minimamente processadas possui restrições devido à sua elevada perda da firmeza após o fatiamento. Objetivou-se neste trabalho, avaliar o efeito de ácido ascórbico (AA, cloreto de cálcio (CC, cloridrato de L-cisteína (Cis e Na2EDTA, empregados em associação com a atmosfera modificada, na prevenção do amaciamento de banana 'Maçã' minimamente processada. Foram utilizadas as seguintes combinações: 1 (AA 1% + CC 1% + Cis 0,5%; 2 (AA 1% + CC 1% + Cis 1%; 3 (AA 1% + CC 1% + Cis 1,5%; 4 (Na2EDTA 1%, constituindo os 4 tratamentos de um delineamento inteiramente casualizado. As bananas, no estádio de maturação 6, foram tratadas com uma solução de hipoclorito de sódio 500 ppm, descascadas e fatiadas manualmente, submetidas aos tratamentos químicos por imersão e embaladas com filme de PVC de 30µm. Posteriormente, foram armazenadas durante 5 dias à temperatura de 5 ± 1ºC e 85 ± 3% UR. A perda de massa foi linear durante o período de armazenamento, e maior nas fatias tratadas com Na2EDTA 1%. A perda da firmeza foi menor nas fatias sob o tratamento 3, o qual apresentou menores valores de atividade da poligalacturonase até o 3º dia de armazenamento. Após o 2º dia de armazenamento, as fatias sob o tratamento 4 exibiram a maior atividade de pectinametilesterase, e aquelas sob os tratamentos 2 e 3, as menores. Foi observado um maior teor de pectina solúvel e de sólidos solúveis totais nas fatias tratadas com EDTA, sobretudo a partir do 3º dia de armazenamento. O aumento no teor de açúcares solúveis totais foi maior nos tratamentos 1 e 2 até o 3º dia de armazenamento. A mistura química 3 (AA 1% + CC 1% + Cis 1,5% foi a mais efetiva em evitar o amaciamento de banana 'Maçã' minimamente processada.The use of banana in minimally processed fruit salads have restrictions due to their high lost of firmness after cutting. The goal of this work was to evaluate the effects of ascorbic acid

  12. Caracterização química e física de batatas 'Ágata' minimamente processadas, embaladas sob diferentes atmosferas modificadas ativas Chemical and physical characterization of fresh-cut 'Ágata' potatoes packed under different active modified atmospheres

    Directory of Open Access Journals (Sweden)

    Lívia Lacerda Oliveira Pineli

    2005-10-01

    Full Text Available O objetivo deste trabalho foi avaliar as alterações químicas e físicas em batatas 'Ágata' minimamente processadas, embaladas sob diferentes atmosferas, durante o armazenamento refrigerado. Batatas 'Ágata' foram minimamente processadas como minibatatas e embaladas em filmes de náilon multicamadas. Os tratamentos aplicados no momento da embalagem foram o vácuo parcial e as misturas 10%CO2, 2%O2, 88%N2 ou 5%CO2, 5%O2, 90%N2. Em seguida, foram armazenadas a 5ºC. A cada três dias, amostras foram avaliadas quanto ao índice de escurecimento, atividade da polifenoloxidase e peroxidase, firmeza, sólidos solúveis totais e acidez titulável. O armazenamento sob vácuo parcial foi o mais eficaz no controle do escurecimento, da minimização da atividade da polifenoloxidase e da peroxidase, prevenindo alterações nos teores de sólidos solúveis totais, redução da firmeza, encharcamento da embalagem e maior acidez titulável. Os demais tratamentos apresentaram rápido desenvolvimento do escurecimento, aumento de firmeza em decorrência de ressecamento dos tubérculos, elevação nos sólidos solúveis totais e menor desenvolvimento da acidez em comparação ao tratamento sob vácuo parcial. A utilização de vácuo parcial foi a mais recomendada para a manutenção da qualidade das minibatatas. Todavia, outros tratamentos que busquem a manutenção da firmeza e frescor, sem o desenvolvimento de off-flavors e sem escurecimento, devem ser avaliados.The objective of this work was to evaluate chemical and physical characteristics of fresh-cut 'Ágata' potatoes packed under different active modified atmospheres, during refrigerated storage. 'Ágata' potatoes were minimally processed as baby potatoes and packed in nylon multilayer films. The treatments applied were partial vacuum, and atmospheres with 10%CO2, 2%O2, 88%N2 and 5%CO2, 5%O2, 90%N2. After that, they were stored at 5ºC. Every three days, tubers were evaluated for browning index

  13. Baryogensis in fresh inflation

    CERN Document Server

    Bellini, M

    2002-01-01

    I study the possibility of baryogenesis can take place in fresh inflation. I find that it is possible that violation of baryon number conservation can occur during the period out-of-equilibrium in this scenario. Indeed, baryogenesis could be possible before the thermal equilibrium is restored at the end of fresh inflation.

  14. Bioremediation of soil contaminated with spent and fresh cutting ...

    African Journals Online (AJOL)

    As such contaminants constitute risk to human health; they can enter the food ... White rot fungus, Pleurotus pulmonarius was investigated in this pilot study for its ... Copper, manganese and nickel decreased significantly by 35.3, 25.0 and ...

  15. Importance of Seed Quality for the Fresh-cut Chain

    DEFF Research Database (Denmark)

    Deleuran, Lise Christina; Olesen, Merete Halkjær; Shetty, Nisha

    2011-01-01

    Seed is the most fundamental input in vegetable production on, which the effectiveness of other inputs and outputs depends. If the seed is of poor quality, the use of other inputs is less successful and will occasionally be irrelevant. A definition of seed quality will depend upon the use for, wh...

  16. Qualidade de produtos minimamente processados e comercializados em gôndolas de supermercados nas cidades de Lavras - MG, Brasília - DF e São Paulo - SP Quality of fresh-cut produce commercialized on supermarket shelves in the cities of Lavras-MG, Brasília-DF, and São Paulo-SP

    Directory of Open Access Journals (Sweden)

    Nélio Ranieli Ferreira de Paula

    2009-02-01

    Full Text Available A produção de frutos e hortaliças minimamente processados mostrou crescimento relevante nos últimos anos, em razão de acentuadas mudanças no estilo de vida do consumidor, como redução das famílias, busca de conveniência e conscientização da necessidade de uma dieta alimentar saudável e que atenda às exigências de segurança alimentar. Objetivou-se, neste trabalho, caracterizar a qualidade química, físico-química e microbiológica dos produtos minimamente processados, coletados em gôndolas de supermercados em Lavras - MG, Brasília - DF e São Paulo - SP para orientar seus fornecedores e consumidores quanto à necessidade de maior controle de qualidade, devido aos riscos de contaminação de matérias-primas por microrganismos patogênicos e deteriorantes. 144 amostras foram coletadas e submetidas às determinações de pH, acidez titulável e sólidos solúveis e avaliações microbiológicas (coliformes a 45ºC, Escherichia coli e Salmonella sp.. Os resultados mostraram variações significativas nos valores de pH e foi observada diminuição de acidez e sólidos solúveis, durante o armazenamento. Foi detectada contaminação por coliformes a 45ºC sendo que, em 50% dessa presença, houve isolamentos de Escherichia coli, evidenciando contaminação oriunda de matéria-prima inadequadamente higienizada ou por sua presença nos manipuladores. Contudo, não foi detectada contaminação por Salmonella sp.. Os resultados obtidos indicaram a necessidade de implementação de Boas Práticas de Fabricação (BPF, no controle de qualidade desses produtos.The production of fresh-cut fruits and vegetables has shown an outstanding growth in the latest years, due to the remarkable changes in the consumers' life style, such as family reduction, search for convenience and increased awareness of a wholesome food diet which meets the requirements of food safety. The aim of this work was to characterize the physicochemical and microbiological

  17. Volatile profile and physical, chemical, and biochemical changes in fresh cut watermelon during storage Perfil volátil e alterações físicas, químicas e bioquímicas na melancia minimamente processada durante o armazenamento

    Directory of Open Access Journals (Sweden)

    Andréa Luiza Ramos Pereira Xisto

    2012-03-01

    Full Text Available Existing data about the aroma of fresh-cut watermelon and the metabolic changes that occur with minimal processing are scarce. Given the close relationship that exists between aroma, texture, and quality characteristics, it is necessary to investigate the changes in the volatile profile and texture of watermelon, a fruit extensively sold in supermarket chains throughout Brazil. The objective of this work was to analyze the volatile profile using solid phase microextraction (SPME as well as texture changes in fresh-cut watermelon stored at 5 °C for ten days. Chromatography associated with sensory analysis (sniffing led us to conclude that 9-carbon (C9 alcohols and aldehydes are the major responsible for the flavor and aroma of minimally processed watermelon stored at 5 ± 1 °C/90 ± 5% RH for ten days, and also that the aroma diminishes in intensity with storage, but it does not affect the final quality of the product. It was noted that the amount of drained liquid, soluble pectin, and weight loss increased during storage concurrently with a reduction in firmness and a structural breakdown of the cells. Pectin methyl esterase activity remained constant and polygalacturonase activity was not detected.Existe pouca informação a respeito do aroma de melancia minimamente processada e das alterações metabólicas que ocorrem com o processamento mínimo. Sabendo-se que há estreita relação entre aroma característico, textura e qualidade torna-se necessário o conhecimento a respeito das alterações do perfil volátil e textura deste produto, que é intensamente comercializado nas redes de supermercados do Brasil. Diante disso, o objetivo deste trabalho foi analisar o perfil volátil utilizando a técnica de microextração em fase sólida (SPME e as modificações relacionadas à textura de melancia minimamente processada armazenada a 5 °C, por dez dias. A cromatografia associada com análise sensorial ('sniffing' permitiu concluir que os

  18. Influência de sanificantes nas características microbiológicas, físicas e físico-químicas de cebola (Allium cepa L. minimamente processada Effect of sanitizers on the microbial, physical and physical-chemical characteristics of fresh-cut onions (Allium cepa L

    Directory of Open Access Journals (Sweden)

    Karla Michalsky Carvalho Beerli

    2004-02-01

    âmetros analisados, a qualidade da cebola se manteve adequada para o consumo em todos os tratamentos até o sétimo dia após o processamento, incluindo o tratamento-controle (sem sanificante.The goal of this work was to evaluate the effect of hydrogen peroxide (H2O2 and sodium dichloroisocianurate (NaDCC sanitizers on the shelf-life of fresh-cut onion, based on the microbial development and physical and physical-chemical characteristics. The onions were washed, peeled and sliced. The following treatments were tested using three randomized blocks: H2O2 (2%, H2O2 (4%, H2O2 (6%, NaDCC (50ppm and NaDCC (100ppm. The slices were packed and stored at 4ºC for 7 days, after sanitation. One package for treatment was used daily and the following variables were evaluated: standard counting of mesophile aerobic microorganisms, total counting of psychrotrophs aerobic microorganisms, moulds and yeasts, total coliforms at 35ºC and 45ºC, total soluble solids (TSS, pH, titratable acidity (TA, firmness and mass loss. Lower counting of mesophile aerobic were found in slices treated with H2O2; all treatments, but control, were effective in decreasing psychrotroph aerobic and total coliforms at 35ºC; coliforms 45ºC were not found in slices of any treatment; only H2O2 (4% and H2O2 (6% treatments decreased the values of moulds and yeasts; the treatments did not affect the TSS and mass loss; NaDCC treatments promoted higher pH; lower TA were found in slices treated with H2O2 (4%, H2O2 (6% and NaDCC (50ppm and higher firmness were obtained in slices treated with H2O2 (4% and H2O2 (6%. From the results it is concluded that H2O2 (4 and 6% was more effective sanitizer for fresh-cut onions than NaDCC; according the analyzed parameters, the fresh-cut onion was held in proper edible conditions for 7 days after processing, including the control (without sanitizer.

  19. Foodborne outbreaks and potential routes of contamination in fresh and fresh-cut fruits and vegetables

    Science.gov (United States)

    Outbreaks of Salmonella spp., Listeria monocytogenes, and Escherichia coli O157:H7 have been associated with mangoes, cantaloupes, and leafy green commodities, respectively. The 2011 outbreak of L. monocytogenes associated with the consumption of contaminated Rocky Ford cantaloupes was one of the m...

  20. The center-cut solution.

    Science.gov (United States)

    Firnstahl, T W

    1993-01-01

    Timothy Firnstahl owns five successful restaurants in Seattle, but he recently came very close to owning none. In the early 1990s, he found himself, like so many restauranteurs, facing rising costs, inefficient management, and a recession. Confronting financial annihilation, Firnstahl had to act quickly: since he had no peripherals to trim, he cut off the head of his company. Remarkably, it worked. Firnstahl's problem was his new and innovative restaurant, Sharps Fresh Roasting. The heart of the Sharps concept was a unique long-roasting technique that made lean, inexpensive meats taste as juicy and delicious as fattier, expensive cuts. The process also lent itself to faster service and lower labor costs. But it wasn't working. Sharps wasn't breaking even, and his other restaurants couldn't make up the difference. He needed a solution fast. Firnstahl got his answer from Mikhail Gorbachev: slash the centralized command and liberate the company. In doing so, he would also transfer virtually all power and responsibility to his line managers. And after five months of intensive study and planning, he accomplished what he set out to do. He fired most of his corporate staff, empowered his restaurant managers with "100% Power and Responsibility," and, finally, undertook a massive promotion campaign. A year later, Sharps Fresh Roasting is the gold mine Firnstahl always believed it could be. He's done away with bureaucracy and turned business around in a down market. All this because his managers are managing themselves.

  1. Intelligent Fish Freshness Assessment

    Directory of Open Access Journals (Sweden)

    Hamid Gholam Hosseini

    2008-01-01

    Full Text Available Fish species identification and automated fish freshness assessment play important roles in fishery industry applications. This paper describes a method based on support vector machines (SVMs to improve the performance of fish identification systems. The result is used for the assessment of fish freshness using artificial neural network (ANN. Identification of the fish species involves processing of the images of fish. The most efficient features were extracted and combined with the down-sampled version of the images to create a 1D input vector. Max-Win algorithm applied to the SVM-based classifiers has enhanced the reliability of sorting to 96.46%. The realisation of Cyranose 320 Electronic nose (E-nose, in order to evaluate the fish freshness in real-time, is experimented. Intelligent processing of the sensor patterns involves the use of a dedicated ANN for each species under study. The best estimation of freshness was provided by the most sensitive sensors. Data was collected from four selected species of fishes over a period of ten days. It was concluded that the performance can be increased using individual trained ANN for each specie. The proposed system has been successful in identifying the number of days after catching the fish with an accuracy of up to 91%.

  2. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber-laser...... cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  3. Multibeam Fibre Laser Cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre-laser...... cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

  4. Flexible Laser Metal Cutting

    DEFF Research Database (Denmark)

    Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

    2014-01-01

    This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

  5. Cutting state identification

    Energy Technology Data Exchange (ETDEWEB)

    Berger, B.S.; Minis, I.; Rokni, M. [Univ. of Maryland, College Park, MD (United States)] [and others

    1997-12-31

    Cutting states associated with the orthogonal cutting of stiff cylinders are identified through an analysis of the singular values of a Toeplitz matrix of third order cumulants of acceleration measurements. The ratio of the two pairs of largest singular values is shown to differentiate between light cutting, medium cutting, pre-chatter and chatter states. Sequences of cutting experiments were performed in which either depth of cut or turning frequency was varied. Two sequences of experiments with variable turning frequency and five with variable depth of cut, 42 cutting experiments in all, provided a database for the calculation of third order cumulants. Ratios of singular values of cumulant matrices find application in the analysis of control of orthogonal cutting.

  6. Simulation of Laser Cutting

    Science.gov (United States)

    Schulz, Wolfgang; Nießen, Markus; Eppelt, Urs; Kowalick, Kerstin

    Laser cutting is a thermal separation process widely used in shaping and contour cutting applications. There are, however, gaps in understanding the dynamics of the process, especially issues related to cut quality. This work describes the advances in fundamental physical modelling and process monitoring of laser cutting, as well as time varying processes such as contour cutting. Diagnosis of ripple and dross formation is advanced to observe the melt flow and its separation simultaneously as well as the spatial shape of the cut kerf.

  7. Global Shortage of Fresh Water

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>阅读下表。以Global Shortage of Fresh Water为题写一篇短文。词数:100—120学生习作:Global Shortage of Fresh Water Fresh water seems ineverywhere,in rivers,lakes,wells as well as rain,which make some people think that we can’t use up water.

  8. Processamento mínimo do melão Cantaloupe com uso de doses de cloreto de cálcio e quelato aminocálcico Fresh-cut of Cantaloupe melon using doses of calcium chloride and calcium amino acid chelate

    Directory of Open Access Journals (Sweden)

    Francisca Ligia de C Machado

    2008-03-01

    Full Text Available A qualidade de melão Cantaloupe 'Hy-Mark' minimamente processado em cubos, tratado com cloreto de cálcio ou quelato aminocálcico e armazenado sob refrigeração foi avaliada. Os frutos foram colhidos em estádio de maturação comercial, caracterizado por camada de abscisão do pedúnculo com até 75% de desprendimento, teor de sólidos solúveis mínimo de 9.0ºBrix, coloração externa verde-escuro e firmeza da polpa máxima de 18 N, no Agropolo Mossoró-Assu (RN, e transportados para o laboratório da Embrapa Agroindústria Tropical, onde foram selecionados, sanitizados, processados e tratados a 10ºC. Posteriormente os cubos foram imersos em cálcio a 0,5% e 1,0%, na forma de cloreto de cálcio e cálcio 0,5% e 1% na forma de quelato aminocálcico por três minutos, drenados, acondicionados em embalagens PET e armazenados a 5±1ºC e 90±5% UR por 18 dias. As análises de aparência, coloração, firmeza da polpa, teores de cálcio total e livre, sólidos solúveis totais, acidez total titulável e pH foram realizadas logo após o processamento e em intervalos de três dias até o décimo oitavo dia. A aplicação de cálcio na forma de cloreto de cálcio e quelato aminocálcico reteve a firmeza da polpa e conservou a aparência das amostras por todo o período experimental, destacando-se principalmente a aplicação de 1,0% de cálcio na forma de cloreto de cálcio que não só resultou em maior retenção da firmeza, como também proporcionou os maiores teores de cálcio total.The quality of fresh-cut Cantaloupe 'Hy-Mark' melon treated with calcium chloride or calcium amino acid chelate and stored under refrigeration was studied. Fruits were harvested at commercial maturity, taking into consideration slip stage when only 25% of the stem remained intact upon removal from the vine, soluble solids no lower than 9.0ºBrix, firmness no higher than 18N, and dark green color of the rind. Fruits were transported to the postharvest laboratory

  9. Estimate of respiration rate and physicochemical changes of fresh-cut apples stored under different temperatures Estimativa da taxa de respiração e das mudanças físico-químicas de maçãs minimamente processadas e estocadas sob diferentes temperaturas

    Directory of Open Access Journals (Sweden)

    Cristiane Fagundes

    2013-03-01

    Full Text Available In this study, the influence of storage temperature and passive modified packaging (PMP on the respiration rate and physicochemical properties of fresh-cut Gala apples (Malus domestica B. was investigated. The samples were packed in flexible multilayer bags and stored at 2 °C, 5 °C, and 7 °C for eleven days. Respiration rate as a function of CO2 and O2 concentrations was determined using gas chromatography. The inhibition parameters were estimated using a mathematical model based on Michaelis-Menten equation. The following physicochemical properties were evaluated: total soluble solids, pH, titratable acidity, and reducing sugars. At 2 °C, the maximum respiration rate was observed after 150 hours. At 5 °C and 7 °C the maximum respiration rates were observed after 100 and 50 hours of storage, respectively. The inhibition model results obtained showed a clear effect of CO2 on O2 consumption. The soluble solids decreased, although not significantly, during storage at the three temperatures studied. Reducing sugars and titratable acidity decreased during storage and the pH increased. These results indicate that the respiration rate influenced the physicochemical properties.Neste estudo, a influência da temperatura de armazenamento e da embalagem com atmosfera modificada passiva (AMP na taxa respiratória e nas propriedades físico-químicas de maçãs da variedade Gala (Malus domestica, B. minimamente processadas foi investigada. As amostras foram acondicionadas em embalagens flexíveis e armazenados a 2 °C, 5 °C e 7 °C, durante 11 dias. A taxa de respiração foi gerada para diferentes concentrações de O2 e CO2, obtidas por cromatografia gasosa. Os parâmetros de inibição foram estimados por um modelo matemático baseado na equação de Michaelis-Menten. Foram avaliadas as seguintes propriedades físico-químicas: sólidos solúveis totais, pH, acidez titulável e açúcares redutores. A 2 °C, a taxa de respiração máxima foi

  10. Advances in Study of the Effect of High Pressure on Quality and Microbes of Fresh-Cut Fruits and Vegetables%高压处理对鲜切果蔬品质与微生物影响的研究进展

    Institute of Scientific and Technical Information of China (English)

    张学杰; 叶志华

    2014-01-01

    提,也是保障鲜切果蔬高压产品品质与安全的有效措施。未来鲜切果蔬高压研究将面向数字化模拟高压对果蔬细胞结构的影响、高压下鲜切果蔬风味的控制、联合高压技术开发及适宜高压加工的鲜切果蔬原料品种的选择等。%This article reviewed the research proceeding on fresh cut fruits and vegetables processed by high pressure technology, which involved in the effect of high pressure on sensory quality, nutritional quality, antioxidant capability, enzymes, microorganisms and cell structure of fresh cut fruits and vegetables. The future research direction was also discussed. High pressure processing (HPP) is a non-thermal food processing method that subjects foods (liquid or solid) to pressures between 50 and 1 000 MPa. The suitable HPP can improve the taste of FCFV products, while higher pressure (>200 MPa) has an adverse effect on the sensory quality. The nutritional quality of FCFV products by HPP is affected by raw material and treatments, lower pressure can increase the antioxidant capability, compared to the adverse effect by the higher pressure. Most enzymes related to quality of FCFV products are steady at lower pressure and even some enzymes were activated at some pressures, enzyme activities are decreased significantly when pressure increased over 400 MPa and some enzymes are inactivated especially by>600 MPa. The degree of inactivation of micro-organisms depends on different factors: micro-organism type, amount of pressure, treatment temperature and time, etc., the inactivation of micro-organisms are observed at HPP, while there will exist a high risk if the micro-organisms are not inactivate completely by HPP, even FCFV products are stored at 4℃. The pressure<300 MPa can not inactivate micro-organisms in FCFV products completely, although it also depends on raw materials and the original populations of micro-organisms. HPP faced challenges against the control of safety of FCFV

  11. Reduction of radiation injury of fresh agricultural products by saccharide

    Energy Technology Data Exchange (ETDEWEB)

    Hayashi, Toru; Todoroki, Setsuko [National Food Research Inst., Tsukuba, Ibaraki (Japan)

    1998-02-01

    To establish irradiation technologies as one of alternative technology of methyl bromide fumigation, radiation sensitivities for each kind of fresh agricultural products and reduction of radiation injury were investigated. Fresh vegetables and flowers such as cabbage, sprouts, asparagus, lettuce, chrysanthemum, carnation, rose, etc. were used and irradiated with 750 Gy {gamma}-ray. Flowers received radiation injury were soaked into various kinds of solutions for one night, then they were irradiated with 500 Gy {gamma}-ray. They showed different radiation sensitivities. Cruciferae plant showed radioresistance and Compositae plant radiosensitivity. A keeping quality agent for cut flowers indicated protection effect on radiation injury. (S.Y.)

  12. Device for cutting protrusions

    Science.gov (United States)

    Bzorgi, Fariborz M.

    2011-07-05

    An apparatus for clipping a protrusion of material is provided. The protrusion may, for example, be a bolt head, a nut, a rivet, a weld bead, or a temporary assembly alignment tab protruding from a substrate surface of assembled components. The apparatus typically includes a cleaver having a cleaving edge and a cutting blade having a cutting edge. Generally, a mounting structure configured to confine the cleaver and the cutting blade and permit a range of relative movement between the cleaving edge and the cutting edge is provided. Also typically included is a power device coupled to the cutting blade. The power device is configured to move the cutting edge toward the cleaving edge. In some embodiments the power device is activated by a momentary switch. A retraction device is also generally provided, where the retraction device is configured to move the cutting edge away from the cleaving edge.

  13. Irradiation of fresh fish

    Science.gov (United States)

    Yueh-jen, Yen; Jin-lai, Zhou; Shao-chun, Lai

    Occasionally, in China, marine products can not be provided for the markets in good quality, for during the time when they are being transported from the sea port to inland towns or even at the time when they are unloaded from the ship, they are beginning to spoil. Obviously, it is very important that appropiate measures should be taken to prevent them from decay. Our study has proved that the shelf life of fresh Flatfish (Cynoglossue robustus) and Silvery pomfret (stromateoides argenteus), which, packed in sealed containers, are irradiated by 1.5 kGy, 2.2 kGy and 3.0 kGy, can be stored for about 13-26 days at 3° - 5° C.

  14. Recent Developments in Film and Gas Research in Modified Atmosphere Packaging of Fresh Foods.

    Science.gov (United States)

    Zhang, Min; Meng, Xiangyong; Bhandari, Bhesh; Fang, Zhongxiang

    2016-10-01

    Due to the rise of consumer's awareness of fresh foods to health, in the past few years, the consumption of fresh and fresh-cut produces has increased sturdily. Modified atmosphere packaging (MAP) possesses a potential to become one of the most appropriate technologies for packaging fresh and fresh-cut produces. The MAP has advantages of extending the shelf-life, preserving or stabilizing the desired properties of fresh produces, and convenience in handing and distribution. The success of MAP-fresh foods depends on many factors including types of fresh foods, storage temperature and humidity, gas composition, and the characteristics of package materials. This paper reviews the recent developments highlighting the most critical factors of film and gas on the quality of MAP fresh foods. Although the innovations and development of food packaging technology will continue to promote the development of novel MAP, concentrated research and endeavors from scientists and engineers are still important to the development of MAP that focuses on consumers' requirements, enhancing product quality, environmental friendly design, and cost-effective application.

  15. Graphs of Plural Cuts

    CERN Document Server

    Dosen, K

    2011-01-01

    Plural (or multiple-conclusion) cuts are inferences made by applying a structural rule introduced by Gentzen for his sequent formulation of classical logic. As singular (single-conclusion) cuts yield trees, which underlie ordinary natural deduction derivations, so plural cuts yield graphs of a more complicated kind, related to trees, which this paper defines. Besides the inductive definition of these oriented graphs, which is based on sequent systems, a non-inductive, graph-theoretical, combinatorial, definition is given, and to reach that other definition is the main goal of the paper. As trees underlie multicategories, so the graphs of plural cuts underlie polycategories. The graphs of plural cuts are interesting in particular when the plural cuts are appropriate for sequent systems without the structural rule of permutation, and the main body of the paper deals with that matter. It gives a combinatorial characterization of the planarity of the graphs involved.

  16. Laser Cutting, Development Trends

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    1999-01-01

    In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting o...... of 3-dimensional shapes.The CO2-laser will also in the near future be the dominating laser source in the market, although the new developments in ND-YAG-lasers opens for new possibilities for this laser type.......In this paper a short review of the development trends in laser cutting will be given.The technology, which is the fastest expanding industrial production technology will develop in both its core market segment: Flat bed cutting of sheet metal, as it will expand in heavy industry and in cutting...

  17. Respiration rate of gamma irradiation carnation cut flowers

    Energy Technology Data Exchange (ETDEWEB)

    Kikuchi, Olivia Kimiko; Wiendl, Frederico Maximiliano [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil); Todoriki, Setsuko; Nakahara, Kazuhiko; Haysahi, Toru [National Food Research Inst., Ibaraki (Japan)

    1996-07-01

    The present paper presents the CO{sub 2} production of the carnation cut flowers gamma-irradiated with a single dose of 750 Gy. The cut flowers were soaked in preservative solutions, containing germicides or germicides plus 2% sucrose. The irradiation did not change the CO{sub 2} production and did not cause any visible flower damage. The sucrose exogenous supply extended the vase-life of both irradiated and non-irradiated carnations. These results indicated that Nora carnation cut flower can be irradiated with 750 Gy without commercial viability loss and that it is possible to use the radiation to disinfect this fresh product. (author)

  18. Laser cutting plastic materials

    Energy Technology Data Exchange (ETDEWEB)

    Van Cleave, R.A.

    1980-08-01

    A 1000-watt CO/sub 2/ laser has been demonstrated as a reliable production machine tool for cutting of plastics, high strength reinforced composites, and other nonmetals. More than 40 different plastics have been laser cut, and the results are tabulated. Applications for laser cutting described include fiberglass-reinforced laminates, Kevlar/epoxy composites, fiberglass-reinforced phenolics, nylon/epoxy laminates, ceramics, and disposable tooling made from acrylic.

  19. Ultrasonic Cutting of Foods

    Science.gov (United States)

    Schneider, Yvonne; Zahn, Susann; Rohm, Harald

    In the field of food engineering, cutting is usually classified as a mechanical unit operation dealing with size reduction by applying external forces on a bulk product. Ultrasonic cutting is realized by superpositioning the macroscopic feed motion of the cutting device or of the product with a microscopic vibration of the cutting tool. The excited tool interacts with the product and generates a number of effects. Primary energy concentration in the separation zone and the modification of contact friction along the tool flanks arise from the cyclic loading and are responsible for benefits such as reduced cutting force, smooth cut surface, and reduced product deformation. Secondary effects such as absorption and cavitation originate from the propagation of the sound field in the product and are closely related to chemical and physical properties of the material to be cut. This chapter analyzes interactions between food products and ultrasonic cutting tools and relates these interactions with physical and chemical product properties as well as with processing parameters like cutting velocity, ultrasonic amplitude and frequency, and tool design.

  20. Saving Seal Cutting

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    On April 20, the graduation ceremony of China’s seal-cutting art postgraduates and visiting experts from the Institute of Seal Cutting Art under the China Art Academy was held in Beijing. On the same day, the exhibition of the works of the teachers and graduates of the institute was also held.

  1. Cutting Class Harms Grades

    Science.gov (United States)

    Taylor, Lewis A., III

    2012-01-01

    An accessible business school population of undergraduate students was investigated in three independent, but related studies to determine effects on grades due to cutting class and failing to take advantage of optional reviews and study quizzes. It was hypothesized that cutting classes harms exam scores, attending preexam reviews helps exam…

  2. Fundamentals of cutting.

    Science.gov (United States)

    Williams, J G; Patel, Y

    2016-06-06

    The process of cutting is analysed in fracture mechanics terms with a view to quantifying the various parameters involved. The model used is that of orthogonal cutting with a wedge removing a layer of material or chip. The behaviour of the chip is governed by its thickness and for large radii of curvature the chip is elastic and smooth cutting occurs. For smaller thicknesses, there is a transition, first to plastic bending and then to plastic shear for small thicknesses and smooth chips are formed. The governing parameters are tool geometry, which is principally the wedge angle, and the material properties of elastic modulus, yield stress and fracture toughness. Friction can also be important. It is demonstrated that the cutting process may be quantified via these parameters, which could be useful in the study of cutting in biology.

  3. Online Cake Cutting

    CERN Document Server

    Walsh, Toby

    2010-01-01

    We propose an online form of the cake cutting problem. This models situations where players arrive and depart during the process of dividing a resource. We show that well known fair division procedures like cut-and-choose and the Dubins-Spanier moving knife procedure can be adapted to apply to such online problems. We propose some desirable properties that online cake cutting procedures might possess like online forms of proportionality and envy-freeness, and identify which properties are in fact possessed by the different online cake procedures.

  4. Experimental testing of exchangeable cutting inserts cutting ability

    OpenAIRE

    Čep, Robert; Janásek, Adam; Čepová Lenka; Petrů, Jana; Ivo HLAVATÝ; Car, Zlatan; Hatala, Michal

    2013-01-01

    The article deals with experimental testing of the cutting ability of exchangeable cutting inserts. Eleven types of exchangeable cutting inserts from five different manufacturers were tested. The tested cutting inserts were of the same shape and were different especially in material and coating types. The main aim was both to select a suitable test for determination of the cutting ability of exchangeable cutting inserts and to design such testing procedure that could make it possible...

  5. Testing Of Choiced Ceramics Cutting Tools At Irregular Interrupted Cut

    Science.gov (United States)

    Kyncl, Ladislav; Malotová, Šárka; Nováček, Pavel; Nicielnik, Henryk; Šoková, Dagmar; Hemžský, Pavel; Pitela, David; Holubjak, Jozef

    2015-12-01

    This article discusses the test of removable ceramic cutting inserts during machining irregular interrupted cut. Tests were performed on a lathe, with the preparation which simulated us the interrupted cut. By changing the number of plates mounted in a preparation it simulate us a regular or irregular interrupted cut. When with four plates it was regular interrupted cut, the remaining three variants were already irregular cut. It was examined whether it will have the irregular interrupted cutting effect on the insert and possibly how it will change life of inserts during irregular interrupted cut (variable delay between shocks).

  6. Short-cut math

    CERN Document Server

    Kelly, Gerard W

    1984-01-01

    Clear, concise compendium of about 150 time-saving math short-cuts features faster, easier ways to add, subtract, multiply, and divide. Each problem includes an explanation of the method. No special math ability needed.

  7. Cutting Cakes Correctly

    CERN Document Server

    Hill, Theodore P

    2008-01-01

    Without additional hypotheses, Proposition 7.1 in Brams and Taylor's book "Fair Division" (Cambridge University Press, 1996) is false, as are several related Pareto-optimality theorems of Brams, Jones and Klamler in their 2006 cake-cutting paper.

  8. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  9. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Evren Ozbayoglu; Lei Zhou

    2002-07-30

    This is the fourth quarterly progress report for Year-3 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between April 1, 2002 and June 30, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 3: Addition of a Cuttings Injection/Separation System), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)''; (c) Research project (Task 9b): ''Study of Foam Flow Behavior Under EPET Conditions''; (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''; (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b); (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S); (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  10. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-01-30

    This is the second quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between October 1, 2002 and December 30, 2002. This report presents a review of progress on the following specific tasks. (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System. (b) New research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions''. (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''. (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b). (f) New Research project (Task 13): ''Study of Cuttings Transport with Foam under Elevated Pressure and Temperature Conditions''. (g) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (h) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  11. Chrysanthemum Cutting Productivity and Rooting Ability Are Improved by Grafting

    Directory of Open Access Journals (Sweden)

    Jing Zhang

    2013-01-01

    Full Text Available Chrysanthemum has been commercially propagated by rooting of cuttings, whereas the quality will decline over multiple collections from a single plant. Therefore, we compared the vigour, rooting ability, and some physiological parameters between cuttings harvested from nongrafted “Jinba” (non-grafted cuttings with those collected from grafted “Jinba” plants onto Artemisia scoparia as a rootstock (grafted cuttings. The yield, length, node number, stem diameter, fresh weight, and dry weight of the grafted cuttings were superior to the non-grafted cuttings. Also grafted cuttings “Jinba” rooted 1 day earlier, but showing enhanced rooting quality including number, length, diameter, and dry weight of roots, where compared to the non-grafted. The physiological parameters that indicated contents of soluble protein, peroxidase activity, soluble sugar, and starch, ratios of soluble sugar/nitrogen ratio, and carbohydrate/nitrogen (C/N, as well as contents of indole-3-acetic acid (IAA and abscisic acid (ABA, and IAA/ABA ratio were significantly increased in the grafted cuttings. This suggested their important parts in mediating rooting ability. Results from this study showed that grafting improved productivity and rooting ability related to an altered physiology, which provide a means to meet the increasing demand.

  12. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

    2003-09-30

    The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

  13. Improved cutting performance in high power laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    2003-01-01

    Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

  14. Improved cutting performance in high power laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    2003-01-01

    Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described.......Recent results in high power laser cutting especially with focus on cutting of mild grade steel types for shipbuilding are described....

  15. Determination of cut front position in laser cutting

    Science.gov (United States)

    Pereira, M.; Thombansen, U.

    2016-07-01

    Laser cutting has a huge importance to manufacturing industry. Laser cutting machines operate with fixed technological parameters and this does not guarantee the best productivity. The adjustment of the cutting parameters during operation can improve the machine performance. Based on a coaxial measuring device it is possible to identify the cut front position during the cutting process. This paper describes the data analysis approach used to determine the cut front position for different feed rates. The cut front position was determined with good resolution, but improvements are needed to make the whole process more stable.

  16. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk, Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2002-10-30

    This is the first quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between July 1, 2002 and Sept. 30, 2002. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System, (b) New Research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions'', (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings (Task 12), Viscosity of Foam under EPET (Task 9b). (f) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (g) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  17. Efeito do momento de sanitização sobre atributos fisico-químicos e microbiológicos de beterrabas minimamente processadas Effect of the sanitization moment on physicochemical and microbiological attributes of fresh-cut beet roots

    Directory of Open Access Journals (Sweden)

    Maria Carolina D. Vitti

    2004-12-01

    Full Text Available Raízes de beterrabas, cv. Early Wonder, foram minimamente processadas e submetidas a tratamentos de sanitização: controle (sem sanitização; sanitização após o corte (padrão; sanitização antes do descascamento e após o corte; sanitização apenas após o descascamento; sanitização antes e após o descascamento; sanitização antes e após o descascamento, e após o corte. Após os tratamentos, o produto foi colocado em bandejas envoltas com filme de PVC e armazenado a 5±1°C e 85±5% UR durante 10 dias. Realizou-se análises físico-químicas e microbiológicas durante o armazenamento refrigerado. Não foi detectada a presença de coliformes fecais e Salmonella nos tratamentos com etapa de sanitização. As contagens de coliformes totais e bactérias psicrotróficas e os teores de betacianina e betaxantina foram maiores para beterrabas não sanitizadas. Houve decréscimo nos teores dos pigmentos durante conservação. A sanitização após o descascamento é a mais apropriada para manutenção da qualidade por reduzir a perda de pigmentos e garantir a segurança alimentar do produto, além de evitar o desperdício de cloro.Early Wonder beet roots were minimally processed and submitted to sanitization treatments: control (no sanitization; sanitization after cutting (standard; sanitization before peeling and after cutting; sanitization only after peeling; sanitization before and after peeling; sanitization before and after peeling and after cut. After the treatments, the product was placed on trays wrapped in PVC film and stored at 5±1°C and 85±5% RH for 10 days. Physicochemical and microbiological analyses were conducted during refrigerated storage. Fecal coliforms and Salmonella were not detected in beet roots that underwent sanitization. Total coliforms and psychotropic bacteria counts, as well as betacyanin and betaxanthin amounts were higher in non-sanitized beet roots. There was a decrease in pigment amounts during storage

  18. Dealing with Cuts (For Parents)

    Science.gov (United States)

    ... For Kids For Parents MORE ON THIS TOPIC Cellulitis First Aid: Cuts Staph Infections Bites and Scratches First Aid: Falls First Aid: ... Out Cuts, Scratches, and Abrasions What's a Scab? Cellulitis Cuts, Scratches, and Scrapes Staph Infections Dealing With Cuts and Wounds Contact Us Print ...

  19. Theoretical Models for Orthogonal Cutting

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”......This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”...

  20. Theoretical Models for Orthogonal Cutting

    DEFF Research Database (Denmark)

    De Chiffre, Leonardo

    This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”......This review of simple models for orthogonal cutting was extracted from: “L. De Chiffre: Metal Cutting Mechanics and Applications, D.Sc. Thesis, Technical University of Denmark, 1990.”...

  1. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Lei Zhou

    2000-01-30

    This is the second quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between Oct 1, 2000 and December 31, 2000. This report presents a review of progress on the following specific tasks: (a) Design and development of an Advanced Cuttings Transport Facility (Task 2: Addition of a foam generation and breaker system), (b) Research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (c) Research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (d) Research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (e) Research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Research on instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), and Foam properties while transporting cuttings. (Task 12), (h) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members. The tasks Completed During This Quarter are Task 7 and Task 8.

  2. The perfect cut

    DEFF Research Database (Denmark)

    Scozzafava, G.; Mueller Loose, Simone; Corsi, A.

    (organic, standard, GMO free). The cross-price elasticity provides insights to which degree different cuts compete against each other from a consumer perspective and how price premiums can be achieved by producers and marketers with certification and labeling strategies. The paper will also provide...... other from the consumer perspective dependent on price, intrinsic and extrinsic product characteristics as well as intended usage. So far, there is limited knowledge about optimal marketing and pricing of meat cuts simultaneously offered at the retail shelf. Results from an online choice experiment...

  3. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30

    The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a

  4. 21 CFR 101.95 - “Fresh,” “freshly frozen,” “fresh frozen,” “frozen fresh.”

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false âFresh,â âfreshly frozen,â âfresh frozen,â âfrozen... fresh,” when used on the label or in labeling of a food, mean that the food was quickly frozen while still fresh (i.e., the food had been recently harvested when frozen). Blanching of the food...

  5. CFD modeling to improve safe and efficient distribution of chlorine dioxide gas for packaging fresh produce

    Science.gov (United States)

    The efficiency of the packaging system in inactivating food borne pathogens and prolonging the shelf life of fresh-cut produce is influenced by the design of the package apart from material and atmospheric conditions. Three different designs were considered to determine a specific package design ens...

  6. "Kid Cuts" by Broderbund.

    Science.gov (United States)

    Martin, Ron

    1994-01-01

    Describes "Kid Cuts," an arts and crafts computer software program for students in prekindergarten through sixth grade that provides 22 activities in 6 curriculum areas. An example is given of an activity for kindergarten and first graders related to counting that includes library media skills objectives and mathematics objectives. (LRW)

  7. Cutting Cakes Carefully

    Science.gov (United States)

    Hill, Theodore P.; Morrison, Kent E.

    2010-01-01

    This paper surveys the fascinating mathematics of fair division, and provides a suite of examples using basic ideas from algebra, calculus, and probability which can be used to examine and test new and sometimes complex mathematical theories and claims involving fair division. Conversely, the classical cut-and-choose and moving-knife algorithms…

  8. Simultaneous Cake Cutting

    DEFF Research Database (Denmark)

    Balkanski, Eric; Branzei, Simina; Kurokawa, David;

    2014-01-01

    We introduce the simultaneous model for cake cutting (the fair allocation of a divisible good), in which agents simultaneously send messages containing a sketch of their preferences over the cake. We show that this model enables the computation of divisions that satisfy proportionality — a popular...

  9. Cutting Cakes Carefully

    Science.gov (United States)

    Hill, Theodore P.; Morrison, Kent E.

    2010-01-01

    This paper surveys the fascinating mathematics of fair division, and provides a suite of examples using basic ideas from algebra, calculus, and probability which can be used to examine and test new and sometimes complex mathematical theories and claims involving fair division. Conversely, the classical cut-and-choose and moving-knife algorithms…

  10. Kids Who Cut.

    Science.gov (United States)

    Coy, Doris Rhea; Simpson, Chris

    2002-01-01

    Regardless of whether it is cutting, burning or some other form of self-harm, self-injury is a serious problem requiring serious solutions. This article reviews the various types of self-harm, descriptions of self-mutilators, common myths about self-mutilation, and effective treatment methods. (GCP)

  11. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira

    2000-10-30

    This is the first quarterly progress report for Year 2 of the ACTS project. It includes a review of progress made in Flow Loop development and research during the period of time between July 14, 2000 and September 30, 2000. This report presents information on the following specific tasks: (a) Progress in Advanced Cuttings Transport Facility design and development (Task 2), (b) Progress on research project (Task 8): ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress on research project (Task 6): ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress on research project (Task 7): ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress on research project (Task 9): ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Initiate research on project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions'', (g) Progress on instrumentation tasks to measure: Cuttings concentration and distribution (Tasks 11), and Foam properties (Task 12), (h) Initiate a comprehensive safety review of all flow-loop components and operational procedures. Since the previous Task 1 has been completed, we will now designate this new task as: (Task 1S). (i) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  12. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-04-30

    Experiments on the flow loop are continuing. Improvements to the software for data acquisition are being made as additional experience with three-phase flow is gained. Modifications are being made to the Cuttings Injection System in order to improve control and the precision of cuttings injection. The design details for a drill-pipe Rotation System have been completed. A US Patent was filed on October 28, 2002 for a new design for an instrument that can generate a variety of foams under elevated pressures and temperatures and then transfer the test foam to a viscometer for measurements of viscosity. Theoretical analyses of cuttings transport phenomena based on a layered model is under development. Calibrations of two nuclear densitometers have been completed. Baseline tests have been run to determine wall roughness in the 4 different tests sections (i.e. 2-in, 3-in, 4-in pipes and 5.76-in by 3.5-in annulus) of the flow loop. Tests have also been conducted with aerated fluids at EPET conditions. Preliminary experiments on the two candidate aqueous foam formulations were conducted which included rheological tests of the base fluid and foam stability reports. These were conducted after acceptance of the proposal on the Study of Cuttings Transport with Foam Under Elevated Pressure and Elevated Temperature Conditions. Preparation of a test matrix for cuttings-transport experiments with foam in the ACTF is also under way. A controller for instrumentation to measure cuttings concentration and distribution has been designed that can control four transceivers at a time. A prototype of the control circuit board was built and tested. Tests showed that there was a problem with radiated noise. AN improved circuit board was designed and sent to an external expert to verify the new design. The new board is being fabricated and will first be tested with static water and gravel in an annulus at elevated temperatures. A series of viscometer tests to measure foam properties have

  13. A rapid and simple DNA extraction procedure to detect Salmonella spp. and Listeria monocytogenes from fresh produce using real-time PCR

    Science.gov (United States)

    DNA isolation procedures significantly influence the outcome of PCR-based detection of human pathogens. Unlike clinical samples, DNA isolation from food samples such as fresh and fresh-cut produce has remained a formidable task and has hampered the sensitivity and accuracy of molecular methods. We...

  14. Cutting forces during turning with variable depth of cut

    Directory of Open Access Journals (Sweden)

    M. Sadílek

    2016-03-01

    The proposed research for the paper is an experimental work – measuring cutting forces and monitoring of the tool wear on the cutting edge. It compares the turning where standard roughing cycle is used and the turning where the proposed roughing cycle with variable depth of cut is applied.

  15. Cutting Out Continuations

    DEFF Research Database (Denmark)

    Bahr, Patrick; Hutton, Graham

    2016-01-01

    In the field of program transformation, one often transforms programs into continuation-passing style to make their flow of control explicit, and then immediately removes the resulting continuations using defunctionalisation to make the programs first-order. In this article, we show how these two...... transformations can be fused together into a single transformation step that cuts out the need to first introduce and then eliminate continuations. Our approach is calculational, uses standard equational reasoning techniques, and is widely applicable....

  16. Manual bamboo cutting tool.

    Science.gov (United States)

    Bezerra, Mariana Pereira; Correia, Walter Franklin Marques; da Costa Campos, Fabio Ferreira

    2012-01-01

    The paper presents the development of a cutting tool guide, specifically for the harvest of bamboo. The development was made based on precepts of eco-design and ergonomics, for prioritizing the physical health of the operator and the maintenance of the environment, as well as meet specific requirements of bamboo. The main goal is to spread the use of bamboo as construction material, handicrafts, among others, from a handy, easy assembly and material available tool.

  17. Making the cut

    OpenAIRE

    Millard, Chris

    2013-01-01

    ‘Deliberate self-harm’, ‘self-mutilation’ and ‘self-injury’ are just some of the terms used to describe one of the most prominent issues in British mental health policy in recent years. This article demonstrates that contemporary literature on ‘self-harm’ produces this phenomenon (to varying extents) around two key characteristics. First, this behaviour is predominantly performed by those identified as female. Second, this behaviour primarily involves cutting the skin. These constitutive char...

  18. Soluble oil cutting fluid

    Energy Technology Data Exchange (ETDEWEB)

    Rawlinson, A.P.; White, J.

    1987-06-23

    A soluble oil, suitable when diluted with water, for use as a cutting fluid comprises an alkali or alkaline-earth metal alkyl benzene sulphonate, a fatty acid diethanolamide, a mixed alkanolamine borate, a polyisobutenesuccinimide and a major proportion of mineral oil. The soluble oil is relatively stable without the need for a conventional coupling agent and some soluble oil emulsions are bio-static even though conventional biocides are not included.

  19. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Mark Pickell; Len Volk; Mike Volk; Barkim Demirdal; Affonso Lourenco; Evren Ozbayoglu; Paco Vieira; Neelima Godugu

    2000-07-30

    ACTS flow loop is now operational under elevated pressure and temperature. Currently, experiments with synthetic based drilling fluids under pressure and temperature are being conducted. Based on the analysis of Fann 70 data, empirical correlations defining the shear stress as a function of temperature, pressure and the shear rate have been developed for Petrobras synthetic drilling fluids. PVT equipment has been modified for testing Synthetic oil base drilling fluids. PVT tests with Petrobras Synthetic base mud have been conducted and results are being analyzed Foam flow experiments have been conducted and the analysis of the data has been carried out to characterize the rheology of the foam. Comparison of pressure loss prediction from the available foam hydraulic models and the test results has been made. Cuttings transport experiments in horizontal annulus section have been conducted using air, water and cuttings. Currently, cuttings transport tests in inclined test section are being conducted. Foam PVT analysis tests have been conducted. Foam stability experiments have also been conducted. Effects of salt and oil concentration on the foam stability have been investigated. Design of ACTS flow loop modification for foam and aerated mud flow has been completed. A flow loop operation procedure for conducting foam flow experiments under EPET conditions has been prepared Design of the lab-scale flow loop for dynamic foam characterization and cuttings monitoring instrumentation tests has been completed. The construction of the test loop is underway. As part of the technology transport efforts, Advisory Board Meeting with ACTS-JIP industry members has been organized on May 13, 2000.

  20. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Ergun Kuru; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Gerald Kane; Len Volk; Mark Pickell; Evren Ozbayoglu; Barkim Demirdal; Paco Vieira; Affonso Lourenco

    1999-10-15

    This report includes a review of the progress made in ACTF Flow Loop development and research during 90 days pre-award period (May 15-July 14, 1999) and the following three months after the project approval date (July15-October 15, 1999) The report presents information on the following specific subjects; (a) Progress in Advanced Cuttings Transport Facility design and development, (b) Progress report on the research project ''Study of Flow of Synthetic Drilling Fluids Under Elevated Pressure and Temperature Conditions'', (c) Progress report on the research project ''Study of Cuttings Transport with Foam Under LPAT Conditions (Joint Project with TUDRP)'', (d) Progress report on the research project ''Study of Cuttings Transport with Aerated Muds Under LPAT Conditions (Joint Project with TUDRP)'', (e) Progress report on the research project ''Study of Foam Flow Behavior Under EPET Conditions'', (f) Progress report on the instrumentation tasks (Tasks 11 and 12) (g) Activities towards technology transfer and developing contacts with oil and service company members.

  1. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-07-30

    This Quarter has been divided between running experiments and the installation of the drill-pipe rotation system. In addition, valves and piping were relocated, and three viewports were installed. Detailed design work is proceeding on a system to elevate the drill-string section. Design of the first prototype version of a Foam Generator has been finalized, and fabrication is underway. This will be used to determine the relationship between surface roughness and ''slip'' of foams at solid boundaries. Additional cups and rotors are being machined with different surface roughness. Some experiments on cuttings transport with aerated fluids have been conducted at EPET. Theoretical modeling of cuttings transport with aerated fluids is proceeding. The development of theoretical models to predict frictional pressure losses of flowing foam is in progress. The new board design for instrumentation to measure cuttings concentration is now functioning with an acceptable noise level. The ultrasonic sensors are stable up to 190 F. Static tests with sand in an annulus indicate that the system is able to distinguish between different sand concentrations. Viscometer tests with foam, generated by the Dynamic Test Facility (DTF), are continuing.

  2. Performance Testing of Cutting Fluids

    DEFF Research Database (Denmark)

    Belluco, Walter

    within the whole range of operations, materials, cutting fluids, operating conditions, etc. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping, and with respect to tool life, cutting forces, chip formation and product quality (dimensional accuracy and surface integrity......). A number of different work materials were considered, with emphasis on austenitic stainless steel. Cutting fluids from two main groups were investigated, water miscible (reviewed from previous work) and straight oils. Results show that correlation of cutting fluid performance in different operations exists...... within the same group of cutting fluids, for stainless steel. A possible rationalisation of cutting fluid performance tests is suggested. In order to select a set of basic tests and optimise them for use as general and standardised testing methods, an original approach to the evaluation of cutting force...

  3. Performance Testing of Cutting Fluids

    DEFF Research Database (Denmark)

    Belluco, Walter

    The importance of cutting fluid performance testing has increased with documentation requirements of new cutting fluid formulations based on more sustainable products, as well as cutting with minimum quantity of lubrication and dry cutting. Two sub-problems have to be solved: i) which machining...... tests feature repeatability, reproducibility and sensitivity to cutting fluids, and ii) to what extent results of one test ensure relevance to a wider set of machining situations. The present work is aimed at assessing the range of validity of the different testing methods, investigating correlation...... within the whole range of operations, materials, cutting fluids, operating conditions, etc. Cutting fluid performance was evaluated in turning, drilling, reaming and tapping, and with respect to tool life, cutting forces, chip formation and product quality (dimensional accuracy and surface integrity...

  4. Analysis of forces in conventional and ultrasonically assisted plane cutting of cortical bone.

    Science.gov (United States)

    Alam, Khurshid; Khan, Mushtaq; Silberschmidt, Vadim V

    2013-06-01

    Bone cutting is a well accepted but technically demanding surgical procedure in orthopaedics. A level of tool penetration force during cutting of bones has been the prime concern to surgeons, since it can produce unnecessary mechanical damage to surrounding tissues. Research in this area has been undertaken for many decades to find ways to minimise the cutting force. Cutting of bone with ultrasonic tools is a relatively new technique replacing conventional procedures in neuro-, dental and orthopaedic surgeries, due to its precision and safety. In this article, the level of forces produced during a chisel-like tool penetration in a fresh cortical bone is studied. The obtained force data are analysed for both conventional cutting and ultrasonically assisted cutting. Through a series of experiments, it was demonstrated that the depth of cut and parameters of ultrasonic oscillations affected the level of cutting force, the former being the main factor in both types of cutting. It was found that the tool penetration force was decreased with an increase in the ultrasonic frequency or amplitude and was not affected by the cutting speed. The rise in bone temperature was measured and was found to be insensitive to the level of cutting speed within the range used in this study.

  5. Cutting the Cord-2

    Science.gov (United States)

    2004-01-01

    This animation shows the view from the rear hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting from the front lander petal. Before this crucial turn took place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

  6. Cutting the Cord

    Science.gov (United States)

    2004-01-01

    This animation shows the view from the front hazard avoidance cameras on the Mars Exploration Rover Spirit as the rover turns 45 degrees clockwise. This maneuver is the first step in a 3-point turn that will rotate the rover 115 degrees to face west. The rover must make this turn before rolling off the lander because airbags are blocking it from exiting off the front lander petal. Before this crucial turn could take place, engineers instructed the rover to cut the final cord linking it to the lander. The turn took around 30 minutes to complete.

  7. Drilling cost-cutting

    Energy Technology Data Exchange (ETDEWEB)

    Capuano, L.E. Jr.

    1996-12-31

    This presentation by Louis E. Capuano, Jr., President, ThermaSource, Inc., discusses cost-cutting in the drilling phase of geothermal energy exploration and production. All aspects of a geothermal project including the drilling must be streamlined to make it viable and commercial. If production could be maximized from each well, there would be a reduction in drilling costs. This could be achieved in several ways, including big hole and multi-hole completion, directional drilling, better knowledge of the resource and where to penetrate, etc.

  8. Improved performance of linear coal cutting compared with rotary cutting

    Energy Technology Data Exchange (ETDEWEB)

    Roepke, W.W.; Hanson, B.D.; Olson, R.C.; Wingquist, C.F.; Myren, T.A.

    1995-09-01

    The linear cutting system, developed by the US Bureau of Mines uses geometric principles developed by Cardan to produce a nearly constant cut depth. The new system has been extensively tested in a synthetic material under laboratory conditions to verify mechanical capability and to identify operational characteristics. Comparison between 15-rpm linear cutting and 50-rpm rotary cutting systems show significant improvement in respirable dust entrainment, product size distribution, and energy usage. Respirable dust is reduced by as much as 90%. Recovered product showed a 67% reduction in {minus}0.32-cm ({minus}1/8-in) material and a 200% increase in +5.08 cm (+ 2 in) materials. Average power was reduced by 66% for the linear cutting. Because the bit cutting paths differ between linear and rotary cutting, it was necessary to compare the two at the same cut depths and bit types. These comparisons show that low revolution per minute rotary cutting entrains about the same amount of respirable dust as the linear cutting system, but the average shaft torque may be 55 to 130% greater for the rotary system.

  9. Fresh inflation with increasing cosmological parameter

    CERN Document Server

    Bellini, M

    2003-01-01

    I study a fresh inflationary model with an increasing F-cosmological parameter. The model provides sufficiently e-folds to solve the flatness/horizon problem and the density fluctuations agree with experimental values. The temperature increases during fresh inflation and reach its maximum value when inflation ends. I find that entropy perturbations always remain below $10^{-4}$ during fresh inflation and become negligible when fresh inflation ends. Hence, the adiabatic fluctuations dominate the primordial spectrum at the end of fresh inflation.

  10. CO2 laser cutting

    CERN Document Server

    Powell, John

    1998-01-01

    The laser has given manufacturing industry a new tool. When the laser beam is focused it can generate one of the world's most intense energy sources, more intense than flames and arcs, though similar to an electron beam. In fact the intensity is such that it can vaporise most known materials. The laser material processing industry has been growing swiftly as the quality, speed and new manufacturing possibilities become better understood. In the fore of these new technologies is the process of laser cutting. Laser cutting leads because it is a direct process substitu­ tion and the laser can usually do the job with greater flexibility, speed and quality than its competitors. However, to achieve these high speeds with high quality con­ siderable know how and experience is required. This information is usually carefully guarded by the businesses concerned and has to be gained by hard experience and technical understanding. Yet in this book John Powell explains in lucid and almost non­ technical language many o...

  11. ADVANCED CUTTINGS TRANSPORT STUDY

    Energy Technology Data Exchange (ETDEWEB)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi

    2004-01-31

    Final design of the mast was completed (Task 5). The mast is consisting of two welded plate girders, set next to each other, and spaced 14-inches apart. Fabrication of the boom will be completed in two parts solely for ease of transportation. The end pivot connection will be made through a single 2-inch diameter x 4 feet-8 inch long 316 SS bar. During installation, hard piping make-ups using Chiksan joints will connect the annular section and 4-inch return line to allow full movement of the mast from horizontal to vertical. Additionally, flexible hoses and piping will be installed to isolate both towers from piping loads and allow recycling operations respectively. Calibration of the prototype Foam Generator Cell has been completed and experiments are now being conducted. We were able to generate up to 95% quality foam. Work is currently underway to attach the Thermo-Haake RS300 viscometer and install a view port with a microscope to measure foam bubble size and bubble size distribution. Foam rheology tests (Task 13) were carried out to evaluate the rheological properties of the proposed foam formulation. After successful completion of the first foam test, two sets of rheological tests were conducted at different foam flow rates while keeping other parameters constant (100 psig, 70F, 80% quality). The results from these tests are generally in agreement with the previous foam tests done previously during Task 9. However, an unanticipated observation during these tests was that in both cases, the frictional pressure drop in 2 inch pipe was lower than that in the 3 inch and 4 inch pipes. We also conducted the first foam cuttings transport test during this quarter. Experiments on aerated fluids without cuttings have been completed in ACTF (Task 10). Gas and liquid were injected at different flow rates. Two different sets of experiments were carried out, where the only difference was the temperature. Another set of tests was performed, which covered a wide range of

  12. Vortex cutting in superconductors

    Science.gov (United States)

    Glatz, A.; Vlasko-Vlasov, V. K.; Kwok, W. K.; Crabtree, G. W.

    2016-08-01

    Vortex cutting and reconnection is an intriguing and still-unsolved problem central to many areas of classical and quantum physics, including hydrodynamics, astrophysics, and superconductivity. Here, we describe a comprehensive investigation of the crossing of magnetic vortices in superconductors using time dependent Ginsburg-Landau modeling. Within a macroscopic volume, we simulate initial magnetization of an anisotropic high temperature superconductor followed by subsequent remagnetization with perpendicular magnetic fields, creating the crossing of the initial and newly generated vortices. The time resolved evolution of vortex lines as they approach each other, contort, locally conjoin, and detach, elucidates the fine details of the vortex-crossing scenario under practical situations with many interacting vortices in the presence of weak pinning. Our simulations also reveal left-handed helical vortex instabilities that accompany the remagnetization process and participate in the vortex crossing events.

  13. Quality characteristics of fried lamb nuggets from low-value meat cuts

    DEFF Research Database (Denmark)

    Medina, Milagros; Antequera, Teresa; Ruiz Carrascal, Jorge;

    2015-01-01

    This study revealed the possibility of manufacturing prefried lamb nuggets from low-value cuts (flank) and evaluated the effect of formulation (50:50 vs. 20:80 of leg/flank cuts) and freezing (−20 ℃ for two months) on different quality parameters. Frying process produced a decrease of water content...... not to a level high enough to influence the sensory perception by consumers. So that, frozen nuggets from both formulations showed similar consumer acceptance to freshly produced ones with quite good scores (3.46–3.86 out of 5). Thus, low-value lamb cuts are suitable for being processed into highly acceptable...

  14. Laser Cutting of Different Materials

    Directory of Open Access Journals (Sweden)

    Kadir ÇAVDAR

    2013-08-01

    Full Text Available In this paper; in general potential developments and trends of a particular machining field by extensively evaluating present studies of laser beam machining have been discussed. As it is indicated below, technical literatures have been subsumed under five major headlines: Experimental studies, reviews, optimization researches of the cutting parameters, theoretical modelling studies of laser beam cutting and academic studies relating to laser cutting

  15. CALCULATION OF LASER CUTTING COSTS

    Directory of Open Access Journals (Sweden)

    Bogdan Nedic

    2016-09-01

    Full Text Available The paper presents description methods of metal cutting and calculation of treatment costs based on model that is developed on Faculty of mechanical engineering in Kragujevac. Based on systematization and analysis of large number of calculation models of cutting with unconventional methods, mathematical model is derived, which is used for creating a software for calculation costs of metal cutting. Software solution enables resolving the problem of calculating the cost of laser cutting, comparison' of costs made by other unconventional methods and provides documentation that consists of reports on estimated costs.

  16. Effects of planting date and plant density on crop growth of cut chrysanthemum

    NARCIS (Netherlands)

    Lee, J.H.; Heuvelink, E.; Challa, H.

    2002-01-01

    The effects of planting date (season) and plant density (32, 48 or 64 plants m-2) on growth of cut chrysanthemum (Chrysanthemum (Indicum group)) were investigated in six greenhouse experiments, applying the expolinear growth equation. Final plant fresh and dry mass and number of flowers per plant de

  17. Dominus for cut flower production

    Science.gov (United States)

    Fumigation with methyl bromide was the principal method of soilborne pest control in cut flower production. Many cut flower growers in Florida have ceased production, but those that remain are restricted in the fumigants that they are able to utilize due to proximity to potable water sources and oc...

  18. Will Intel Grow Through Cuts?

    Institute of Scientific and Technical Information of China (English)

    DAN; STEINBOCK

    2006-01-01

    Short-term cuts, perhaps, but long-term growth in China may be inevitable T he world's largest chipmaker, Intel, is sending a ripple effect through its pool of labor globally, including in China, with the announcement of deep workforce cuts.

  19. Rimbaud Cut-Up Burroughs

    Directory of Open Access Journals (Sweden)

    Mauricio Vasconcelos

    1996-10-01

    Full Text Available O objetivo deste ensaio é o de explorar a relação entre a poesia de Rimbaud e as experiências de William Burroughs com os cut-ups. A influência de Rimbaud sobre o trabalho de Burroughs se estende, contudo, para além dos cut-ups, envolvendo sua escrita ficcional.

  20. OPTIMAL CONTROL OF CNC CUTTING PROCESS

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    The intelligent optimizing method of cutting parameters and the cutting stable districts searching method are set up. The cutting parameters of each cutting pass could be optimized automatically, the cutting chatter is predicted through setting up the dynamic cutting force AR(2) model on-line, the spindle rotation speed is adjusted according to the predicting results so as to ensure the cutting system work in stable district.

  1. Online Cake Cutting (published version)

    CERN Document Server

    Walsh, Toby

    2011-01-01

    We propose an online form of the cake cutting problem. This models situations where agents arrive and depart during the process of dividing a resource. We show that well known fair division procedures like cut-and-choose and the Dubins-Spanier moving knife procedure can be adapted to apply to such online problems. We propose some fairness properties that online cake cutting procedures can possess like online forms of proportionality and envy-freeness. We also consider the impact of collusion between agents. Finally, we study theoretically and empirically the competitive ratio of these online cake cutting procedures. Based on its resistance to collusion, and its good performance in practice, our results favour the online version of the cut-and-choose procedure over the online version of the moving knife procedure.

  2. Cutting forces in orthogonal cutting of unidirectional GFRP composites

    Energy Technology Data Exchange (ETDEWEB)

    Caprino, G.; Nele, L. [Univ. of Naples Federico II (Italy). Dept. of Materials and Production Engineering

    1996-07-01

    The results of orthogonal cutting tests carried out on unidirectional glass fiber reinforced plastic composites, using HSS tools, are presented and discussed. During the tests, performed on a milling machine at very low cutting speed to avoid thermal effects, the cutting speed was held constant and parallel to the fiber direction. Three parameters, namely the tool rake angle {alpha}, the tool relief angle {gamma}, and the depth of cut t, were varied. According to the experimental results, the horizontal force per unit width, F{sub hu}, undergoes a dramatic decrease, never verified for metals, with increasing {alpha}. Besides, F{sub hu} is only negligibly affected by the relief angle, and linearly increases with t. Similarly to metals, an effect of the depth of cut on the specific energy (size effect) is found also for composites. However, the presented results indicate that the size effect can be analytically modeled in a simple way in the case of composites. The vertical force per unit width, F{sub vu}, exhibits a marked reduction when the relief angle is increased. F{sub vu} is also very sensitive to the rake angle: the lower {alpha}, the higher is F{sub vu}. It is shown that this behavior probably reflects a strong influence of the rake angle on the forces developing at the flank. A linear dependence of the vertical force on the depth of cut is also demonstrated. Finally, the experimental data are utilized to obtain empirical formulae, allowing an approximate evaluation of cutting forces.

  3. Detection of fresh-cut produce processing residues on food contact surface materials using hyperspectral imaging

    Science.gov (United States)

    To reduce the risk of foodborne-illness, produce processors currently clean and sanitize food contact surfaces daily before production starts. Current methods to verify the efficacy of cleaning procedures include visual inspection and direct surface sampling using ATP bioluminescence assays and cul...

  4. EFFECT OF COLD PLASMA TREATMENT ON THE FUNCTIONAL PROPERTIES OF FRESH-CUT APPLES.

    Science.gov (United States)

    Ramazzina, Ileana; Tappi, Silvia; Rocculi, Pietro; Sacchetti, Giampiero; Berardinelli, Annachiara; Marseglia, Angela; Rizzi, Federica

    2016-10-06

    The atmospheric double barrier discharge (DBD) plasma technology is a promising tool in food industry as an alternative to traditional food preservation methods. However, the effect of the reactive chemical species generated during the treatment on the qualitative and quantitative content of bioactive compounds in food is still little studied, as well as there are no data concerning potential deleterious effects of DBD treated foods on human cells. We measured antioxidants content and antioxidant capacity of DBD-treated minimally processed Pink Lady® apples in comparison with untreated matched samples. Moreover, we compared the effects of polyphenols extracts obtained from DBD-treated apples on cell viability, reactive oxygen species production and phase II enzyme activation. The results show that the plasma treatment causes a slight reduction of antioxidant content and antioxidant capacity. Noteworthy, apple treated polyphenols extracts do not reduce cell viability and do not suppress the beneficial physiological cell response to oxidative stress.

  5. Effects of storage temperature and fruit ripening on firmness of fresh cut tomatoes

    NARCIS (Netherlands)

    Moreira Lana, M.; Tijskens, L.M.M.; Kooten, van O.

    2005-01-01

    Tomato fruit (cultivar Belissimo) were harvested at three different stages of ripening, sliced and stored at at 2, 5, 8, 12 and 16 °C. Firmness was measured as the force necessary to cause a deformation of 3 mm, in the outer and the radial pericarp, daily or every two days, depending on the combinat

  6. Mechanical Stress Results in Immediate Accumulation of Glucosinolates in Fresh-Cut Cabbage

    National Research Council Canada - National Science Library

    Požrl, Tomaž; Cigić, Blaž; Demšar, Lea; Hribar, Janez; Polak, Tomaž

    2015-01-01

    The intensity of mechanical stress and the temperature significantly affect the levels of individual and total glucosinolates in shredded white cabbage (cv. Galaxy). Mild processing (shredding to 2 mm thickness) at 8...

  7. Assessment of changes in optical properties of fresh-cut tomato using video image analysis

    NARCIS (Netherlands)

    Moreira Lana, M.; Tijskens, L.M.M.; Theije, A.; Hogenkamp, M.; Kooten, van O.

    2006-01-01

    Tomato fruit (Lycopersicon esculentum cv. Belissimo) at different stages of maturity were sliced in 7-mm thick transverse slices and stored at 5 °C. In a second experiment, slices obtained from fruit at the light-red stage were stored at temperatures from 5 to 13 °C. Intact control fruit were stored

  8. The pink eye syndrome does not impair tuber fresh cut wound-related responses

    Science.gov (United States)

    The potato tuber pink eye (PE) syndrome is a costly physiological disorder that results in corruption of the native periderm, susceptibility to infection, water vapor loss and associated shrinkage, roughened and cracked tuber surfaces, and various related blemishes and defects. PE results in aberra...

  9. Mechanical Stress Results in Immediate Accumulation of Glucosinolates in Fresh-Cut Cabbage

    Directory of Open Access Journals (Sweden)

    Tomaž Požrl

    2015-01-01

    Full Text Available The intensity of mechanical stress and the temperature significantly affect the levels of individual and total glucosinolates in shredded white cabbage (cv. Galaxy. Mild processing (shredding to 2 mm thickness at 8°C resulted in the accumulation of glucosinolates (40% increase in comparison with unshredded cabbage, which was already seen 5 min after the mechanical stress. Severe processing (shredding to 0.5 mm thickness at 20°C, however, resulted in an initial 50% decrease in glucosinolates. The glucosinolates accumulated in all of the cabbage samples 30 min from processing, resulting in higher levels than in unshredded cabbage, except for the severe processing at 20°C where the increase was not sufficient to compensate for the initial loss. Glucobrassicin and neoglucobrassicin were the major glucosinolates identified in the cabbage samples. Mechanical stress resulted in an increase in the relative proportion of glucobrassicin and in a decrease in neoglucobrassicin.

  10. The Multi - vitamin Nutrient Fresh Vegetable Juice

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ In the Tenth Five- Year Plan period, an important strategy for food industry is to develop fruit vegetable freshening and processing industry. Now,the consumable demand for vegetables turns to fresh,convenient, nutritious, safe and dean ones, while semi-processed vegetables and mixed fresh vegetable juices will meet this market demand exactly.

  11. A model for discrimination freshness of shrimp

    Directory of Open Access Journals (Sweden)

    Linong Du

    2015-12-01

    Full Text Available The shrimp is popular for its nutrition and dainty, however, it is easy to decay, and its freshness degrades, so, it is important to assess its freshness. The shrimp gives off unpleasant odor with its freshness change, detecting its odor difference can evaluate its freshness. The feasibility of using electronic nose for evaluating the freshness of shrimp (Penaeus vanmamei is explored in this paper. The odor of shrimp, stored at 5 °C, was detected by the electronic nose. Combined with the sensory evaluation and TVBN, a model based on the electronic nose was constructed to evaluate the shrimp freshness. In principal components analysis, the first three principal components accounted for 86.97% of total variation, and they are used to establish a model to estimate the shrimp freshness with Fisher Liner Discriminant. The discriminant rates were 98.3% for 120 modeling sample data, and 91.7% for 36 testing sample data. The model could be easily used to evaluate the freshness of shrimp with better accuracy.

  12. Consumers' store choice behavior for fresh food

    NARCIS (Netherlands)

    Meulenberg, M.T.G.; Trijp, van J.C.M.

    1991-01-01

    Consumers' preference for fresh food stores is analyzed. In particular the choice between supermarkets and specialized shops for purchasing fresh food is analyzed. Attention is given to the factors influencing this choice. For this purpose a number of research questions with respect to store choice

  13. "Paper Cut Lady" Ku Shulan

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    WHEN the people in Xunyi County of Shaanxi Province talk about the traditional paper cut, they always speak of a "paper cut lady" Ku Shulan. Her works have been shown at the Xi’an Artists’ Gallery, Beijing China Art Gallery and Exhibition Hall of Central Academy of Fine Arts. Almost seventy years old, Ku Shulan is an ordinary country lady, and her artistic achievements were closely linked with her mother countryside. The traditional paper cut created and developed in Xunyi County, has a simple and bold style of Northern Shaanxi, and an exquisitely

  14. AHM cutting expenses, adding technology.

    Science.gov (United States)

    Lutz, S

    1990-04-30

    American Healthcare Management, emerging from bankruptcy protection is cutting corporate costs and expanding into new technology to attract more private-paying patients and lessen dependence on Medicare business.

  15. Refrigerated cutting tools improve machining of superalloys

    Science.gov (United States)

    Dudley, G. M.

    1971-01-01

    Freon-12 applied to tool cutting edge evaporates quickly, leaves no residue, and permits higher cutting rate than with conventional coolants. This technique increases cutting rate on Rene-41 threefold and improves finish of machined surface.

  16. 9 CFR 319.141 - Fresh pork sausage.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Fresh pork sausage. 319.141 Section... INSPECTION AND CERTIFICATION DEFINITIONS AND STANDARDS OF IDENTITY OR COMPOSITION Sausage Generally: Fresh Sausage § 319.141 Fresh pork sausage. “Fresh Pork Sausage” is sausage prepared with fresh pork or...

  17. Optimization of Cutting Variables in Machining

    Institute of Scientific and Technical Information of China (English)

    Zhang Xueyan; Wu Zhenye; Zhou Guohua

    1996-01-01

    With the three criteria for cutting variables proposed by W. W. Gilbert and K.Hitomi, th is paper analyzes the reasonable selection of cutting variables, and further states the relations among maximum profit-oriented cutting speed,minimum cost-oriented cutting speed and maximum productivity-oriented cutting speed. It puts forward a mathematical model for the optimization of cutting variables in machining.

  18. Evaluation of the hemostatic and coagulation effects of AUTO CUT and DRY CUT using a computer-controlled cutting system.

    Science.gov (United States)

    Szyrach, Mara N I; Tolba, Rene H; Voigtländer, Matthias; Neugebauer, Alexander; Enderle, Markus D

    2010-05-01

    To evaluate a newly developed computer-controlled cutting system for the generation of standardized resections and to systematically compare the hemostatic properties and tissue effect of 2 cutting modes, namely, AUTO CUT and DRY CUT used in urologic procedures. An isolated perfused kidney model was used to assess blood loss and coagulation depth after resection of tissue specimens of standardized geometry, size, and cutting velocity with a resection loop. Three different effect settings (E1, E3, and E6; 200 W) of the electrosurgical modes AUTO CUT and DRY CUT were compared. Blood loss was determined semiquantitatively by weighing a swab before and after placing it onto the resection area. The coagulation depth was estimated microscopically on cross sections. The computer-controlled cutting system creates resections of standardized geometry and size with a high reproducibility. An effect level-dependent increase in hemostasis and coagulation depth could be demonstrated with the cutting modes DRY CUT and AUTO CUT using this computer-controlled cutting system. The hemostatic effect with DRY CUT is significantly more pronounced than with AUTO CUT (E1, E3: P computer-controlled cutting system creating reproducible resections in combination with the isolated perfused kidney model offers the possibility to systematically investigate bleeding rate and coagulation depth. The stronger hemostatic properties of the DRY CUT mode are more favorable for urologic interventions requiring a higher hemostatic effect than the AUTO CUT mode. Copyright 2010 Elsevier Inc. All rights reserved.

  19. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment

  20. Modelling global fresh surface water temperature

    NARCIS (Netherlands)

    Beek, L.P.H. van; Eikelboom, T.; Vliet, M.T.H. van; Bierkens, M.F.P.

    2011-01-01

    Temperature directly determines a range of water physical properties including vapour pressure, surface tension, density and viscosity, and the solubility of oxygen and other gases. Indirectly water temperature acts as a strong control on fresh water biogeochemistry, influencing sediment concentrati

  1. Nitrogen uptake kinetics of freshly isolated zooxanthellae

    Digital Repository Service at National Institute of Oceanography (India)

    Wafar, M.V.M.; Wafar, S.; Rajkumar, R.

    Zooxanthellae freshly isolated from the coral host Pocillopora damicornis exhibited substrate-saturable uptake kinetics for ammonium, nitrate and urea. Maximum uptake velocity for ammonium [10.1 nmol. ( mu chl-a)./1h/1] was greater than...

  2. Cut Front Geometry Characterization in Cutting Applications of Brass with Abrasive Water Jet

    Science.gov (United States)

    Akkurt, Adnan

    2010-06-01

    Abrasive water jet (AWJ) cutting is an advanced manufacturing process for machining hard to cut materials. In this study, brass-353 samples of different thicknesses were cut by AWJ using different feed rates to identify the relationships between depth of cut (material thickness), feed rate, and deflection of cutting edge geometry. The effects of material thickness on the AWJ cut surface roughness were investigated and discussed. Deflection of cutting edge geometry in AWJ cutting process was assessed. Cutting edge geometry was characterized by analyzing the surface properties of cut samples.

  3. Urban Fresh Water Resources Consumption of China

    Institute of Scientific and Technical Information of China (English)

    ZHU Peng; LU Chunxia; ZHANG Lei; CHENG Xiaoling

    2009-01-01

    From the point of view of urban consumption behavior, urban fresh water consumption could be classified as three types, namely, direct, indirect and induced water consumption. A calculation approach of urban fresh water consumption was presented based on the theory of urban basic material consumption and the input-output method, which was utilized to calculate urban fresh water consumption of China, and to analyze its structural change and causes. The results show that the total urban fresh water consumption increased 561.7×109m3, and the proportion to the total national fresh water resources increased by 20 percentage points from 1952 to 2005. The proportion of direct and induced water consumption had been continuously rising, and it increased by 15 and 35 percentage points separately from 1952 to 2005, while the proportion of indirect water consumption decreased by 50 percentage points. Urban indi-rect water consumption was mainly related to urban grain, beef and mutton consumption, and urban induced water consumption had a close relationship with the amount of carbon emission per capita. Finally, some countermeasures were put forward to realize sustainable utilization of urban fresh water resources in China.

  4. Extensions of cutting problems: setups

    Directory of Open Access Journals (Sweden)

    Sebastian Henn

    2013-08-01

    Full Text Available Even though the body of literature in the area of cutting and packing is growing rapidly, research seems to focus on standard problems in the first place, while practical aspects are less frequently dealt with. This is particularly true for setup processes which arise in industrial cutting processes whenever a new cutting pattern is started (i.e. a pattern is different from its predecessor and the cutting equipment has to be prepared in order to meet the technological requirements of the new pattern. Setups involve the consumption of resources and the loss of production time capacity. Therefore, consequences of this kind must explicitly be taken into account for the planning and control of industrial cutting processes. This results in extensions to traditional models which will be reviewed here. We show how setups can be represented in such models, and we report on the algorithms which have been suggested for the determination of solutions of the respective models. We discuss the value of these approaches and finally point out potential directions of future research.

  5. Cutting inlays with a laser

    Science.gov (United States)

    Swaczyna, Irena; Grabczewski, Zbigniew

    1995-03-01

    To cut inlay from a stack of glued veneer a CO2 HEBAR-1A laser was used. For setting optimal working parameters of the set used in industrial production of inlay the following elements were defined: the shape and dimensions of the cutting fissure, the dependence between the width of the cutting fissure and the speed with which the laser beam moves and the total thickness of the stack of veneer sheets, the application of the laser for cutting various patterns. Computer aided designing and computer steering of the laser beam enables fast and precise production of large numbers of inlay elements not only from wood but also from other materials like glass, stone, metal, etc. Taking into consideration the high running cost of such a laser set and its very big production only few factories or even one factory in the given area could produce inlay ready for gluing. Further investigation should be carried out on this field particularly considering the lowering of costs not only in inlay production but generally where cutting of wood is concerned.

  6. Equilibrium Analysis in Cake Cutting

    DEFF Research Database (Denmark)

    Branzei, Simina; Miltersen, Peter Bro

    2013-01-01

    Cake cutting is a fundamental model in fair division; it represents the problem of fairly allocating a heterogeneous divisible good among agents with different preferences. The central criteria of fairness are proportionality and envy-freeness, and many of the existing protocols are designed...... to guarantee proportional or envy-free allocations, when the participating agents follow the protocol. However, typically, all agents following the protocol is not guaranteed to result in a Nash equilibrium. In this paper, we initiate the study of equilibria of classical cake cutting protocols. We consider one...... of the simplest and most elegant continuous algorithms -- the Dubins-Spanier procedure, which guarantees a proportional allocation of the cake -- and study its equilibria when the agents use simple threshold strategies. We show that given a cake cutting instance with strictly positive value density functions...

  7. Potentials for export of fresh raspberries from Serbia to EU fresh markets

    Directory of Open Access Journals (Sweden)

    Nikolić Ivan

    2012-12-01

    Full Text Available The aim of this paper is to present potentials of the most significant EU national markets for imports of fresh raspberries from Serbia. We carried out analysis of three markets with highest trade deficit of fresh raspberries expressed in quantities: Germany, Netherlands and Austria. The paper further analyses production and foreign trade trends in selected countries. According to results of this analysis, we identified monthly periods with highest potential for exports of fresh raspberries from Serbia to target markets. The paper also analyses wholesale prices of fresh raspberries and EU policy of direct support to raspberry producers.

  8. Developing and optimizing bacteriophage treatment to control enterohemorrhagic Escherichia coli on fresh produce.

    Science.gov (United States)

    Snyder, Abigail B; Perry, Jennifer J; Yousef, Ahmed E

    2016-11-07

    Bacteriophages are potentially useful in controlling foodborne pathogens on minimally processed products since phage application is a non-destructive treatment. The purpose of this study was to evaluate the efficacy of a newly isolated environmental bacteriophage against enterohemorrhagic Escherichia coli on fresh produce, and optimize the treatment with consideration for potential application. Seven anti E. coli O157:H7 EDL933 bacteriophages were isolated from various sources; the most promising was isolated from municipal wastewater. This isolate (designated as E. coli phage OSY-SP) was propagated with the host, in a growth medium, to a titer of 10(8) PFU/ml. Before inoculation into fresh produce, E. coli phage OSY-SP was incubated with the host bacterium, spent medium was filter-sterilized, and the resulting crude lysate was used as a source of phage inocula for preliminary experiments. For optimized testing, phage in the crude lysate was purified by ultra-centrifugation and resuspension in phosphate-buffered saline. Efficacy of phage treatments was determined as a function of fresh produce type (cut green pepper or spinach leaves), treatment time (2 or 5min rinsing), and temperature of holding treated produce (4°C, 25°, or a combination of both temperatures). Cut green pepper was treated with UV light, to eliminate background microbiota, then spot-inoculated with E. coli O157:H7 EDL933 on cut edges, and the inoculum was allowed to dry. Because of its susceptibility to damage, baby spinach leaves were not subjected to a decontamination treatment. These leaves were inoculated with the green fluorescent protein-labeled E. coli O157:H7 B6-914 to facilitate inoculum enumeration in the presence of background microbiota. Phage suspension was applied to the inoculated fresh produce that was subsequently held for three days under variable storage conditions. The optimized phage treatment decreased the populations of pathogenic E. coli by 2.4-3.0logCFU/g on cut green

  9. Application of water jetfor cutting polymer materials

    Directory of Open Access Journals (Sweden)

    A. Stoić

    2013-04-01

    Full Text Available Due to the nature of polymeric materials, during thermal cutting processes it leads to their melting, and therefore appear errors in the final product. This paper presents a “cold” process of cutting polyamide 6 ie. SIPAS 60, where there are given the characteristics of materials and guidelines for satisfactory quality of process. The authors made the cut experiment 32 were they changed the cutting parameters (cutting pressure, cutting feed and abrasive mass flow; the surface roughness was measured by the depth of material, because the roughness changes with the thickness of the material to be cut.

  10. Cutting temperature measurement and material machinability

    Directory of Open Access Journals (Sweden)

    Nedić Bogdan P.

    2014-01-01

    Full Text Available Cutting temperature is very important parameter of cutting process. Around 90% of heat generated during cutting process is then away by sawdust, and the rest is transferred to the tool and workpiece. In this research cutting temperature was measured with artificial thermocouples and question of investigation of metal machinability from aspect of cutting temperature was analyzed. For investigation of material machinability during turning artificial thermocouple was placed just below the cutting top of insert, and for drilling thermocouples were placed through screw holes on the face surface. In this way was obtained simple, reliable, economic and accurate method for investigation of cutting machinability.

  11. Cutting Characteristics of Force Controllable Milling Head

    Institute of Scientific and Technical Information of China (English)

    Shirakashi; Takahiro; Shibuya; Wataru

    2002-01-01

    In order to control cutting force and its direction i n milling operation, a new milling head was developed. The head has two milling cutters, which are connected by a pair of gears and rotate in opposite direction respectively. Both up-cut and down-cut can be carried out simultaneously by t hese milling cutters. The each depth of cut, the ratio of up/down cutting depth , by these cutters can be also selected. The cutting force characteristics were experimentally discussed by changing the ratio. The cut...

  12. The Cutting Process, Chips and Cutting Forces in Machining CFRP

    DEFF Research Database (Denmark)

    Koplev, A.; Lystrup, Aage; Vorm, T.

    1983-01-01

    The cutting of unidirectional CFRP, perpendicular as well as parallel to the fibre orientation, is examined. Shaping experiments, ‘quick-stop’ experiments, and a new chip preparation technique are used for the investigation. The formation of the chips, and the quality of the machined surface...

  13. Correlation methods in cutting arcs

    Energy Technology Data Exchange (ETDEWEB)

    Prevosto, L; Kelly, H, E-mail: prevosto@waycom.com.ar [Grupo de Descargas Electricas, Departamento Ing. Electromecanica, Universidad Tecnologica Nacional, Regional Venado Tuerto, Laprida 651, Venado Tuerto (2600), Santa Fe (Argentina)

    2011-05-01

    The present work applies similarity theory to the plasma emanating from transferred arc, gas-vortex stabilized plasma cutting torches, to analyze the existing correlation between the arc temperature and the physical parameters of such torches. It has been found that the enthalpy number significantly influence the temperature of the electric arc. The obtained correlation shows an average deviation of 3% from the temperature data points. Such correlation can be used, for instance, to predict changes in the peak value of the arc temperature at the nozzle exit of a geometrically similar cutting torch due to changes in its operation parameters.

  14. Microbiopsy/precision cutting devices

    Science.gov (United States)

    Krulevitch, Peter A.; Lee, Abraham P.; Northrup, M. Allen; Benett, William J.

    1999-01-01

    Devices for performing tissue biopsy on a small scale (microbiopsy). By reducing the size of the biopsy tool and removing only a small amount of tissue or other material in a minimally invasive manner, the risks, costs, injury and patient discomfort associated with traditional biopsy procedures can be reduced. By using micromachining and precision machining capabilities, it is possible to fabricate small biopsy/cutting devices from silicon. These devices can be used in one of four ways 1) intravascularly, 2) extravascularly, 3) by vessel puncture, and 4) externally. Additionally, the devices may be used in precision surgical cutting.

  15. Establishing the Global Fresh Water Sensor Web

    Science.gov (United States)

    Hildebrand, Peter H.

    2005-01-01

    This paper presents an approach to measuring the major components of the water cycle from space using the concept of a sensor-web of satellites that are linked to a data assimilation system. This topic is of increasing importance, due to the need for fresh water to support the growing human population, coupled with climate variability and change. The net effect is that water is an increasingly valuable commodity. The distribution of fresh water is highly uneven over the Earth, with both strong latitudinal distributions due to the atmospheric general circulation, and even larger variability due to landforms and the interaction of land with global weather systems. The annual global fresh water budget is largely a balance between evaporation, atmospheric transport, precipitation and runoff. Although the available volume of fresh water on land is small, the short residence time of water in these fresh water reservoirs causes the flux of fresh water - through evaporation, atmospheric transport, precipitation and runoff - to be large. With a total atmospheric water store of approx. 13 x 10(exp 12)cu m, and an annual flux of approx. 460 x 10(exp 12)cu m/y, the mean atmospheric residence time of water is approx. 10 days. River residence times are similar, biological are approx. 1 week, soil moisture is approx. 2 months, and lakes and aquifers are highly variable, extending from weeks to years. The hypothesized potential for redistribution and acceleration of the global hydrological cycle is therefore of concern. This hypothesized speed-up - thought to be associated with global warming - adds to the pressure placed upon water resources by the burgeoning human population, the variability of weather and climate, and concerns about anthropogenic impacts on global fresh water availability.

  16. Wedge cutting of mild steel by CO 2 laser and cut-quality assessment in relation to normal cutting

    Science.gov (United States)

    Yilbas, B. S.; Karatas, C.; Uslan, I.; Keles, O.; Usta, Y.; Yilbas, Z.; Ahsan, M.

    2008-10-01

    In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.

  17. Preservation technologies for fresh meat - a review.

    Science.gov (United States)

    Zhou, G H; Xu, X L; Liu, Y

    2010-09-01

    Fresh meat is a highly perishable product due to its biological composition. Many interrelated factors influence the shelf life and freshness of meat such as holding temperature, atmospheric oxygen (O(2)), endogenous enzymes, moisture, light and most importantly, micro-organisms. With the increased demand for high quality, convenience, safety, fresh appearance and an extended shelf life in fresh meat products, alternative non-thermal preservation technologies such as high hydrostatic pressure, superchilling, natural biopreservatives and active packaging have been proposed and investigated. Whilst some of these technologies are efficient at inactivating the micro-organisms most commonly related to food-borne diseases, they are not effective against spores. To increase their efficacy against vegetative cells, a combination of several preservation technologies under the so-called hurdle concept has also been investigated. The objective of this review is to describe current methods and developing technologies for preserving fresh meat. The benefits of some new technologies and their industrial limitations is presented and discussed.

  18. Analysis of changes in paper cutting forces during the cutting cycle in single-knife guillotine

    OpenAIRE

    Rusin, Agnieszka; Petriaszwili, Georgij

    2013-01-01

    Paper presents the results of changes in the three components of cutting forces of paper stacks cutting during the cutting cycle in single-knife guillotine. The changes of the three components of cutting force at different stages of cutting cycle were analyzed.

  19. How Can I Stop Cutting?

    Science.gov (United States)

    ... have razors near the tub) listen to soothing music that will shift your mood try a breathing exercise try some relaxing yoga exercises previous continue Things to Help You Express the Pain and Deep Emotion Some people cut because the emotions that they ...

  20. How Can I Stop Cutting?

    Science.gov (United States)

    ... previous continue Things to Help You Express the Pain and Deep Emotion Some people cut because the emotions that they ... may be hard for them to recognize these emotions for what they are — like anger, ... out your hurt, anger, or pain using a pen and paper draw the pain ...

  1. Why I like power cuts...

    CERN Multimedia

    Computer Security Team

    2012-01-01

    Accidental power cuts - a permanent nuisance when running accelerators or computing services, since it takes a lot of time to recover from them. While I feel very sorry for those who are under pressure to get their service running again and deeply regret the loss of down-time and availability, I must admit that I like power cuts: power cuts make computers reboot! And rebooting computers at CERN means all the pending software patches are automatically applied.   But don’t think I am egotistic enough to endorse power cuts. Not necessarily! I am already happy if you regularly patch your computer(s) yourself, where regularly means at least once a month: · If you run a centrally or locally managed Windows computer, give that small orange blinking “CMF” icon in the taskbar a chance in the evening to apply all the pending patches. Also, let it initiate a reboot at the end! · If you have a personal computer with your own Windows operating system, ...

  2. Experimental investigations and finite element simulation of cutting heat in vibrational and conventional drilling of cortical bone.

    Science.gov (United States)

    Wang, Yu; Cao, Meng; Zhao, Xiangrui; Zhu, Gang; McClean, Colin; Zhao, Yuanyuan; Fan, Yubo

    2014-11-01

    Heat generated during bone drilling could cause irreversible thermal damage, which can lead to bone necrosis or even osteomyelitis. In this study, vibrational drilling was applied to fresh bovine bones to investigate the cutting heat in comparison with conventional drilling through experimental investigation and finite element analysis (FEA). The influence of vibrational frequency and amplitude on cutting heat generation and conduction were studied. The experimental results showed that, compared with the conventional drilling, vibrational drilling could significantly reduce the cutting temperature in drilling of cortical bone (P<0.05): the cutting temperature tended to decrease with increasing vibrational frequency and amplitude. The FEA results also showed that the vibrational amplitude holds a significant effect on the cutting heat conduction.

  3. Consumer's Fresh Produce Food Safety Practices: Outcomes of a Fresh Produce Safety Education Program

    Science.gov (United States)

    Scott, Amanda R.; Pope, Paul E.; Thompson, Britta M.

    2009-01-01

    The Centers for Disease Control and Prevention estimate that there are 76 million cases of foodborne disease annually. Foodborne disease is usually associated with beef, poultry, and seafood. However, there is an increasing number of foodborne disease cases related to fresh produce. Consumers may not associate fresh produce with foodborne disease…

  4. Consumer's Fresh Produce Food Safety Practices: Outcomes of a Fresh Produce Safety Education Program

    Science.gov (United States)

    Scott, Amanda R.; Pope, Paul E.; Thompson, Britta M.

    2009-01-01

    The Centers for Disease Control and Prevention estimate that there are 76 million cases of foodborne disease annually. Foodborne disease is usually associated with beef, poultry, and seafood. However, there is an increasing number of foodborne disease cases related to fresh produce. Consumers may not associate fresh produce with foodborne disease…

  5. Microbiological Quality of Fresh Nopal Juice.

    Science.gov (United States)

    Hernández-Anguiano, Ana María; Landa-Salgado, Patricia; Eslava-Campos, Carlos Alberto; Vargas-Hernández, Mateo; Patel, Jitendra

    2016-12-10

    The consumption of fresh nopal cactus juice is widely popular among health-conscious consumers in Mexico. The juice is prepared from fresh cladodes that have only been rinsed with tap water and are not subjected to a pasteurization or terminal bacterial reduction process. The aim of this study was to evaluate the microbial quality of commercially available fresh juices (n = 162) made with nopal in Texcoco, State of Mexico, during the summer and spring season. Standard microbiological methods, the PCR technique and the serological method were used for isolation and identification of bacteria. All samples contained total coliforms and 91% were positive for Escherichia coli. Although total coliforms and E. coli were detected throughout the study, their populations were significantly lower (p nopal juices is unacceptable due to its health significance. The information generated in this study is relevant for human health risk assessment associated with the consumption of unpasteurized nopal juices and potential interventions to minimize pathogen contamination.

  6. Particular applications of food irradiation fresh produce

    Science.gov (United States)

    Prakash, Anuradha

    2016-12-01

    On fresh fruits and vegetables, irradiation at low and medium dose levels can effectively reduce microbial counts which can enhance safety, inhibit sprouting to extend shelf-life, and eliminate or sterilize insect pests which can serve to facilitate trade between countries. At the dose levels used for these purposes, the impact on quality is negligible. Despite the fact that regulations in many countries allow the use of irradiation for fresh produce, the technology remains under-utilized, even in the light of an increase in produce related disease outbreaks and the economic benefits of extended shelf life and reduced food waste. Putative concerns about consumer acceptance particularly for produce that is labeled as irradiated have deterred many companies from using irradiation and retailers to carry irradiated produce. This section highlights the commercial use of irradiation for fresh produce, other than phytosanitary irradiation which is covered in supplementary sections.

  7. SAGD processes with fresh water contact

    Energy Technology Data Exchange (ETDEWEB)

    Thimm, H.F. [Thimm Petroleum Technologies Inc. (Canada)

    2011-07-01

    In the Athabasca region, several bitumen reservoirs are shallow, located less than 400 meters below grade. These deposits are suitable for SAGD exploitation but the steam could come into contact with fresh water, which carries the risk of contaminating this resource. Operators are thus required by regulators to address this issue at the project application stage. The aim of this paper is to examine the potential effect of contact between fresh water and a bitumen bearing zone in a field in Northern Alberta. Investigations were conducted with a steam zone temperature of 200 degree Celsius and measurements were conducted at a plant close to the proposed project. Results showed that the accumulation of hydrogen sulphide would protect the water column and PAH, benzene and toluene were found to be potential concerns but they were not detected during implementation of a similar project. This paper demonstrated that the proposed project does not constitute a threat to fresh water.

  8. 9 CFR 319.142 - Fresh beef sausage.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Fresh beef sausage. 319.142 Section... Sausage § 319.142 Fresh beef sausage. “Fresh Beef Sausage” is sausage prepared with fresh beef or frozen beef, or both, but not including beef byproducts, and may contain Mechanically Separated (Species)...

  9. Leucoagaricus gongylophorus uses leaf-cutting ants to vector proteolytic enzymes towards new plant substrate

    DEFF Research Database (Denmark)

    Kooij, Pepijn Wilhelmus; Rogowska-Wrzesinska, Adelina; Hoffmann, Daniel;

    2014-01-01

    The mutualism between leaf-cutting ants and their fungal symbionts revolves around processing and inoculation of fresh leaf pulp in underground fungus gardens, mediated by ant fecal fluid deposited on the newly added plant substrate. As herbivorous feeding often implies that growth is nitrogen li...... fungi, consistent with previous indications of convergent evolution of decomposition enzymes in attine ant fungal symbionts and phytopathogenic fungi.The ISME Journal advance online publication, 9 January 2014; doi:10.1038/ismej.2013.231....

  10. Quality Analysis of Cutting Steel Using Laser

    Directory of Open Access Journals (Sweden)

    Vladislav Markovič

    2013-02-01

    Full Text Available The article explores the quality dependence of the edge surface of steel C45 LST EN 10083-1 obtained cutting the material using laser on different cutting regimes and variations in the thickness of trial steel. The paper presents the influence of the main modes of laser cutting equipment Trulaser 3030, including cutting speed, pressure, angle and the thickness of the surface on the quality characteristics of the sample. The quality of the edge after laser cutting is the most important indicator influencing such technological spread in industry worldwide. Laser cutting is the most popular method of material cutting. Therefore, the article focuses on cutting equipment, cutting defects and methods of analysis. Research on microstructure, roughness and micro-toughness has been performed with reference to edge samples. At the end of the publication, conclusions are drawn.Article in Lithuanian

  11. Quality Analysis of Cutting Steel Using Laser

    Directory of Open Access Journals (Sweden)

    Vladislav Markovič

    2012-12-01

    Full Text Available The article explores the quality dependence of the edge surface of steel C45 LST EN 10083-1 obtained cutting the material using laser on different cutting regimes and variations in the thickness of trial steel. The paper presents the influence of the main modes of laser cutting equipment Trulaser 3030, including cutting speed, pressure, angle and the thickness of the surface on the quality characteristics of the sample. The quality of the edge after laser cutting is the most important indicator influencing such technological spread in industry worldwide. Laser cutting is the most popular method of material cutting. Therefore, the article focuses on cutting equipment, cutting defects and methods of analysis. Research on microstructure, roughness and micro-toughness has been performed with reference to edge samples. At the end of the publication, conclusions are drawn.Article in Lithuanian

  12. Fibre laser cutting stainless steel: Fluid dynamics and cut front morphology

    Science.gov (United States)

    Pocorni, Jetro; Powell, John; Deichsel, Eckard; Frostevarg, Jan; Kaplan, Alexander F. H.

    2017-01-01

    In this paper the morphology of the laser cut front generated by fibre lasers was investigated by observation of the 'frozen' cut front, additionally high speed imaging (HSI) was employed to study the fluid dynamics on the cut front while cutting. During laser cutting the morphology and flow properties of the melt film on the cut front affect cut quality parameters such as cut edge roughness and dross (residual melt attached to the bottom of the cut edge). HSI observation of melt flow down a laser cutting front using standard cutting parameters is experimentally problematic because the cut front is narrow and surrounded by the kerf walls. To compensate for this, artificial parameters are usually chosen to obtain wide cut fronts which are unrepresentative of the actual industrial process. This paper presents a new experimental cutting geometry which permits HSI of the laser cut front using standard, commercial parameters. These results suggest that the cut front produced when cutting medium section (10 mm thick) stainless steel with a fibre laser and a nitrogen assist gas is covered in humps which themselves are covered by a thin layer of liquid. HSI observation and theoretical analysis reveal that under these conditions the humps move down the cut front at an average speed of approximately 0.4 m/s while the covering liquid flows at an average speed of approximately 1.1 m/s, with an average melt depth at the bottom of the cut zone of approximately 0.17 mm.

  13. Waste Reduction in Fresh Food Supply Chains

    DEFF Research Database (Denmark)

    Kaipia, Riikka; Loikkanen, Lauri; Dukovska-Popovska, Iskra

    2011-01-01

    The paper studies a well-known phenomenon, information sharing in supply chains, in a new context, fresh foods, with a specific goal, supporting sustainable performance in the supply chain. Fresh foods are important for retail stores, representing around half of retail sales, but form a challenging...... and heterogeneous group of products to manage. The value of the paper lies in its pointing out detailed solutions to how in real-life supply chains data can be used efficiently to improve the performance of the supply chain....

  14. Cultivable microbiome of fresh white button mushrooms.

    Science.gov (United States)

    Rossouw, W; Korsten, L

    2017-02-01

    Microbial dynamics on commercially grown white button mushrooms is of importance in terms of food safety assurance and quality control. The purpose of this study was to establish the microbial profile of fresh white button mushrooms. The total microbial load was determined through standard viable counts. Presence and isolation of Gram-negative bacteria including coagulase-positive Staphylococci were performed using a selective enrichment approach. Dominant and presumptive organisms were confirmed using molecular methods. Total mushroom microbial counts ranged from 5·2 to 12·4 log CFU per g, with the genus Pseudomonas being most frequently isolated (45·37% of all isolations). In total, 91 different microbial species were isolated and identified using Matrix-assisted laser desorption ionization-time of flight mass spectrophotometry, PCR and sequencing. Considering current food safety guidelines in South Africa for ready-to-eat fresh produce, coliform counts exceeded the guidance specifications for fresh fruit and vegetables. Based on our research and similar studies, it is proposed that specifications for microbial loads on fresh, healthy mushrooms reflect a more natural microbiome at the point-of-harvest and point-of-sale. Presence and persistence of micro-organisms within the microbiome of fresh produce is important when identifying a potential niche for foodborne pathogens. Most foodborne outbreaks can be attributed to microbial imbalances or lack of diversity within the associated host surface and residing microbial population. Agaricus bisporus samples analysed during this study showed a higher microbial load (5·2 up to 12·4 log CFU per g) compared to known values for other fresh produce. These mushrooms were considered to carry microbial loads representing a healthy and safe product, fit for consumption, despite showing a high indicator incidence. Although foodborne pathogens may be associated on occasion with fresh mushrooms, it remains a low

  15. Characterization of a processed cheese spread produced from fresh cheese (quesito antioqueño

    Directory of Open Access Journals (Sweden)

    Edinson Eliecer Bejarano Toro

    2016-07-01

    Full Text Available Processed products are made from mixes of fresh and ripened cheeses; the use of cheeses with a short shelf-life in the development of processed cheeses is an alternative for the dairy industry. A processed cheese spread was made using only a soft and fatty fresh cheese that had been stored for 25 days. The primary materials were the fresh cheese, water, and emulsifying salts (sodium citrate (E-331 and sodium phosphate (E-450, using a STEPHAN® Universal Machine (UMSK 24E with indirect vapor injection and equipped with rasping and cutting blades. The resulting cheese (A was compared with a commercial cheese (B for compositional, physicochemical, and sensorial characteristics. The cheeses were similar except for the fat in dry matter (FDM, with values of 54.50% and 47.21%, respectively. Sensorially, there were significant differences (P0.05. Cheese A provided, in mg per 100 g of product, 935.823 for phenylalanine, 1003.070 for isoleucine, 2041.420 for leucine, 475.337 for methionine, 119.300 for tryptophan, and 758.347 for valine. Producing processed cheeses with only fresh cheese is possible, resulting in a product that is similar to others that are currently on the market with typical characteristics that are accepted by consumers.

  16. Visible spectroscopy as a tool for the assessment of storage conditions of fresh pork packaged in modified atmosphere

    DEFF Research Database (Denmark)

    Spanos, Dimitrios; Christensen, Mette; Ann Tørngren, Mari

    2016-01-01

    The storage conditions of fresh meat are known to impact its colour and microbial shelf life. In the present study, visible spectroscopy was evaluated as a method to assess meat storage conditions and its optimisation. Fresh pork steaks (longissimus thoracis et lumborum and semimembranosus) were...... placed in modified atmosphere packaging using gas mixtures containing 0, 40, 50, and 80% oxygen, and stored with or without light for up to 9days. Principal component analysis of visible reflectance spectra (400-700nm) showed that the colour of the different meat cuts was affected by presence of oxygen....... The study demonstrates the applicability of visible spectroscopy as a tool to assess the storage conditions of meat cuts packaged in modified atmosphere....

  17. Laser Cutting of Thin Nickel Bellows

    Science.gov (United States)

    Butler, C. L.

    1986-01-01

    Laser cutting technique produces narrow, precise, fast, and repeatable cuts in thin nickel-allow bellows material. Laser cutting operation uses intense focused beam to melt material and assisting gas to force melted material through part thickness, creating void. When part rotated or moved longitudinally, melting and material removal continuous and creates narrow, fast, precise, and repeatable cut. Technique used to produce cuts of specified depths less than material thickness. Avoids distortion, dents, and nicks produced in delicate materials during lathe trimming operations, which require high cutting-tool pressure and holding-fixture forces.

  18. Cutting

    Science.gov (United States)

    ... way some people try to cope with the pain of strong emotions, intense pressure , or upsetting relationship problems . They may ... with difficulties, even big problems and terrible emotional pain. The help of ... or overwhelming emotions. For other tough situations or strong emotions, it ...

  19. Research on Logistics Mode of Fresh Agricultural Products in China

    OpenAIRE

    Xiao Hong; Qi Zhihui

    2013-01-01

    This study has a research on logistics mode of fresh agricultural products in china. Logistics costs are an important part of the price of fresh agricultural products. By researching the characteristics of fresh agricultural products, this study get the main reasons for the high price of fresh agricultural products in China, there are the high logistics cost, large loss and poor preservation in logistics process. Then some measures are proposed to reduce fresh agricultural products logistics ...

  20. Effect of cutting parameters on chip formation in orthogonal cutting

    Directory of Open Access Journals (Sweden)

    S. Ben Salem

    2012-01-01

    Full Text Available Purpose: of this paper is to study the chip formation to obtain the optimal cutting conditions and to observe the different chip formation mechanisms. Analysis of machining of a hardened alloy, X160CrMoV12-1 (cold work steel: AISI D2 with a ferritic and cementite matrix and coarse primary carbides, showed that there are relationships between the chip geometry, cutting conditions and the different micrographs under different metallurgical states.Design/methodology/approach: Machining of hardened alloys has some metallurgical and mechanical difficulties even if many successful processes have been increasingly developed. A lot of study has been carried out on this subject, however only with modest progress showing specific results concerning the real efficiency of chip formation. Hence, some crucial questions remain unanswered: the evolution of white layers produced during progressive tool flank wear in dry hard turning and to correlate this with the surface integrity of the machined surface. For the experimental study here, various cutting speeds and feed rates have been applied on the work material.Findings: The “saw-tooth type chips” geometry has been examined and a specific attention was given to the chip samples that were metallographically processed and observed under scanning electronic microscope (SEM to determine if white layers are present.Research limitations/implications: This research will be followed by a detail modelling and need more experimental results for a given a good prediction of the results occurred on the damage related to the microstructure by using the cutting parameters.Practical implications: A special detail was given to the mechanism of chip formation resulting from hard machining process and behaviour of steel at different metallurgical states on the material during the case of annealing and or the case of quench operations.Originality/value: For the sake of simplicity, ANOVA (Analysis of Variance was used to