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1.
Abstract: Edible flowers have great sensory appeal, but their extremely short shelf life limits their commercial usage. Postharvest 1‐methylcyclopropene (1‐MCP) treatment is used to counter ethylene activity and delay senescence in fresh produce; however, its potential application in edible flowers has not been tested. The objective of this study was to investigate the effect of 1‐MCP treatment with modified atmosphere packaging (MAP) on the shelf life of edible flowers. Freshly harvested carnations and snapdragons were packaged in trays with or without 0.5 μL/L of 1‐MCP, sealed with a gas permeable film, and stored at 5 °C. Package atmospheres, tissue electrolyte leakage, and flower quality were evaluated on days 0, 7, and 14. Treatment with 1‐MCP resulted in significantly slower changes in package headspace O2, CO2, and C2H4 partial pressures, maintained higher overall quality of both flower species and reduced electrolyte leakage and abscission in snapdragon. All samples prepared with MAP had significantly reduced dehydration and higher overall quality compared to flowers packaged commercially in plastic clamshell containers. Treatments with controlled release of 1‐MCP and MAP significantly extended storage life of edible carnation and snapdragon flowers. Practical Application: Edible flowers are currently shipped via air cargo due to their extremely short shelf life. The technology developed in our research significantly extended the storage life of edible flowers, making it possible to ship the edible flowers via ground transportation with significant cost savings. 相似文献
2.
Stephanie R.B. Brown Emily C. Forauer Dennis J. DAmico 《Journal of dairy science》2018,101(9):7768-7779
Queso Fresco has a limited shelf life and has been shown to support the rapid growth of Listeria monocytogenes during refrigerated storage. In addition to improving quality and extending shelf life, modified atmosphere packaging (MAP) has been used to control the growth of pathogenic microorganisms in foods. The objectives of this study were to determine the effects of MAP conditions on the survival and growth of spoilage microorganisms and L. monocytogenes during storage of Queso Fresco manufactured without starter cultures. For L. monocytogenes experiments, cheeses were surface inoculated at ~4 log10 cfu/g before packaging. Inoculated and uninoculated (shelf life experiments) cheeses were placed in 75-µm high-barrier pouches, packaged under 1 of 7 conditions including air, vacuum, or combinations of N2 and CO2 [100% N2 (MAP1), 30% CO2:70% N2 (MAP2), 50% CO2:50% N2 (MAP3), or 70% CO2:30% N2 (MAP4), 100% CO2 (MAP5)], and stored at 7°C. Samples were removed weekly through 35 d of storage. Listeria monocytogenes counts were determined for inoculated samples. Uninoculated samples were assayed for mesophilic and psychrotolerant counts, lactic acid bacteria, coliforms, and yeast and mold. In general, cheeses packaged under conditions consisting of higher contents of CO2 had lower pH levels during storage compared with those stored in conditions with lower levels or no CO2 at all. Similarly, the antimicrobial efficacy of MAP in controlling spoilage microorganisms increased with increasing CO2 content, whereas conditions consisting of 100% N2, vacuum, or air were less effective. Mean L. monocytogenes counts remained near inoculation levels for all treatments at d 1 but increased ~2 log10 cfu/g on cheeses packaged in air, vacuum, and 100% N2 (MAP1) conditions at d 7 and an additional ~1.5 log10 cfu/g at d 14 where they remained through 35 d. In contrast, treatments consisting of 70% CO2 (MAP4) and 100% CO2 (MAP5) limited increases in mean L. monocytogenes counts to <1 log10 cfu/g through 14 d and ~1.5 log10 cfu/g by d 21. Mean L. monocytogenes counts increased to levels significantly higher than inoculation (d 0) on cheeses stored in MAP2 and MAP3 on d 21, on d 28 for MAP4, and on d 35 for cheeses stored under MAP5 conditions. Overall, significant treatment × time interactions were observed between air, vacuum, and MAP1 when each was compared with MAP2, MAP3, MAP4, and MAP5. These data demonstrate that packaging fresh cheese under modified atmospheres containing CO2 may be a promising approach to extend shelf life while limiting L. monocytogenes growth during cold storage. 相似文献
3.
Shelf Life Determination of Sliced Portuguese Traditional Blood Sausage—Morcela de Arroz de Monchique through Microbiological Challenge and Consumer Test
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Jorge A. Pereira Pedro Silva Teresa J. S. Matos Luís Patarata 《Journal of food science》2015,80(3):M642-M648
Morcela de Arroz (MA) is a ready‐to‐eat blood and rice cooked sausage produced with pork, blood, rice, and seasonings, stuffed in natural casing and cooked above 90 °C/30 min. It is commercialized whole, not packed, with a restricted shelf life (1 wk/0 to 5 °C). The objective of this work was to establish sliced MA shelf life considering both the behavior of L. monocytogenes through a microbiological challenge test (MCT) and the consumer acceptability of MA stored: vacuum packed (VP), modified atmosphere packed (MAP: 80% CO2/20% N2), and aerobic packed (AP). The MCT was conducted inoculating ±3 log CFU/g of L. monocytogenes cell suspension on the MA slices. Packaged samples were stored at 3 ± 1 °C and 7 ± 1 °C until 20 d. At 3 ± 1 °C, L. monocytogenes behavior was not affected by packaging or storage time. At 7 ± 1 °C, the pathogen increased nearly 1 log CFU/g in the first 4 d. L. monocytogenes populations in AP were higher (P < 0.05) than in MAP. The pathogen may grow to hazardous levels in the 1st days if a temperature abuse occurs. Considering the acceptability by the consumers, the shelf life of MA stored at 3 ± 1 °C was 4.4 d for AP, 8.1 d for VP, and 10.4 d for MAP. The sensory shelf life established based on sensory spoilage is shorter than the shelf life to maintain the population of L. monocytogenes in safe levels. 相似文献
4.
Abstract: Meatballs were prepared by mixing ground beef and spices and inoculated with E. coli O157:H7, L. monocytogenes, and S. enteritidis before packaged in modified atmosphere (3% O2+ 50% CO2+ 47% N2) or aerobic conditions. The packaged samples were irradiated at 0.75, 1.5, and 3 kGy doses and stored at 4 °C for 21 d. Survival of the pathogens, total plate count, lipid oxidation, color change, and sensory quality were analyzed during storage. Irradiation at 3 kGy inactivated all the inoculated (approximately 106 CFU/g) S. enteritidis and L. monocytogenes cells in the samples. The inoculated (approximately 106 CFU/g) E. coli O157:H7 cells were totally inactivated by 1.5 kGy irradiation. D10‐values for E. coli O157:H7, S. enteritidis, and L. monocytogenes were 0.24, 0.43, and 0.41 kGy in MAP and 0.22, 0.39, and 0.39 kGy in aerobic packages, respectively. Irradiation at 1.5 and 3 kGy resulted in 0.13 and 0.36 mg MDA/kg increase in 2‐thiobarbituric acid‐reactive substances (TBARS) reaching 1.02 and 1.49 MDA/kg, respectively, on day 1. Irradiation also caused significant loss of color and sensory quality in aerobic packages. However, MAP effectively inhibited the irradiation‐induced quality degradations during 21‐d storage. Thus, combining irradiation (3 kGy) and MAP (3% O2+ 50% CO2+ 47% N2) controlled the safety risk due to the potential pathogens and maintained qualities of meatballs during 21‐d refrigerated storage. Practical Application: Combined use of gamma irradiation and modified atmosphere packaging (MAP) can maintain quality and safety of seasoned ground beef (meatball). Seasoned ground beef can be irradiated at 3 kGy and packaged in MAP with 3% O2+ 50% CO2+ 47% N2 gas mixture in a high barrier packaging materials. These treatments can significantly decrease risk due to potential pathogens including E. coli O157:H7, L. monocytogenes, and S. enteritidis in the product. The MAP would reduce the undesirable effects of irradiation on quality, and extend the shelf life of the product for up to 21 d at 3 °C. 相似文献
5.
Mahshad Maghoumi Younes Mostofi Zabihollah Zamani Alireza Talaie Masoud Boojar Perla A. Gómez 《International Journal of Food Science & Technology》2014,49(1):153-159
The impact of heat treatment using hot air (HT 45 °C and 55 °C for 1 h) and two active modified atmosphere packaging (MAP) conditions of high oxygen atmosphere (HOA: 80 kPa O2, 20 kPa N2) and high CO2 atmosphere (HCA: 20 kPa CO2, 80 kPa N2), individually or combined, on the antioxidant capacity, polyphenols, vitamin C content, total anthocyanins, polyphenoloxydase (PPO) activity and shelf life of fresh‐cut (FC) pomegranate arils stored for 14 days at 4 °C was studied. The results indicate that HT 45 °C along with HOA inhibited PPO activity and prevented loss of antioxidant capacity, vitamin C and phenolic compounds in arils, in comparison with control and HT 55 °C. All treatments reduced the accumulation of anthocyanins, but HCA‐treated arils lost more anthocyanins besides having worse a* colour parameter values. No significant differences in titrable acidity (TA) and total soluble solids (TSS) were observed between treatments. The combination of HOA and HT 45 °C enhanced the benefits of applying each treatment separately and could be useful to improve and extend postharvest life of pomegranate FC arils. 相似文献
6.
Payap Masniyom Soottawat Benjakul Wonnop Visessanguan 《Journal of the science of food and agriculture》2002,82(8):873-880
The effect of CO2‐enriched atmosphere in combination with either oxygen or nitrogen on the keeping quality of seabass slices stored at 4 °C was investigated. The inhibitory effect on bacterial growth increased proportionally to the CO2 concentration in the packaging, maximum inhibition being achieved with 100% CO2 (P < 0.05). Seabass slices stored in CO2‐enriched atmosphere had lower total volatile base, trimethylamine, ammonia and formaldehyde contents than those stored in air (P < 0.05). However, increases in lightness and exudate loss were observed for samples packaged in high‐CO2 atmosphere, suggesting the denaturation of both muscle and pigment proteins by carbonic acid formed. Thiobarbituric acid‐reactive substances (TBARS) increased as the CO2 concentration increased (P < 0.05). However, odour, flavour and overall acceptability of CO2‐enriched packaged samples, particularly with 80 and 100% CO2, were acceptable throughout storage for 21 days. Chemical and microbial changes in all samples were generally in agreement with sensory panel evaluations. The shelf‐life of seabass slices packaged in 80–100% CO2 atmosphere could be extended to more than 20 days at 4 °C, compared with 9 days for those packaged in air. © 2002 Society of Chemical Industry 相似文献
7.
Paula Bourke & David O'Beirne 《International Journal of Food Science & Technology》2004,39(5):509-523
The survival and growth of Listeria populations inoculated on to dry coleslaw mix and its components were investigated, focusing on effects of storage temperatures and gas atmospheres within packaging films or storage chambers. There were few significant effects of packaging film at 3 °C, but at 8 °C the elevated CO2/low O2 atmospheres generated within orientated polypropylene (OPP) packages and used in controlled atmosphere chambers were inhibitory. Although two strains of Listeria monocytogenes had survival characteristics comparable with Listeria innocua, L. monocytogenes ATCC 19114 survived better at 3 °C and also in the elevated CO2/low O2 atmospheres within OPP at 8 °C. The effects of product components on the survival of L. innocua were linked to storage temperature. Shredded carrot reduced initial counts and at 8 °C inhibited survival of L. innocua in comparison with shredded cabbage. 相似文献
8.
Elevated concentrations of oxygen on the stability of live mussel stored refrigerated 总被引:2,自引:0,他引:2
The stability of bivalve molluscs was studied in live mussels (Mytilus galloprovincialis) packaged under modified atmospheres. Studies of physical, chemical, microbiological and sensory parameters have detailed these changes in the live packaged mussels. The highest survival was achieved at high oxygen concentrations, i.e. 75%, in the absence of carbon dioxide. The improved storage conditions promote shelf life in 80% of the packaged mussels, reaching a storage life of 6 days when held at 2–3 °C, whereas control molluscs packaged in air did not exceed 3–4 days when stored under the same conditions. Sensory analysis of cooked products from live mussels packaged under 75% oxygen:25% nitrogen were optimum throughout the period of storage. Secondly, the results for the most effective treatment were compared with those for an approximate 75–80% oxygen mixture achieved by applying partial vacuum to the packaging machine. This option employed only oxygen and decreased packaging time, which reduced mussel packaging stress by avoiding elevated vacuum conditions. It provided operational and economic advantage to commercial mussel packaging. 相似文献
9.
Growth Potential of Listeria Monocytogenes and Staphylococcus Aureus on Fresh‐Cut Tropical Fruits
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Ke Feng Wenzhong Hu Aili Jiang Yongping Xu Sarengaowa Xiaobo Li Xue Bai 《Journal of food science》2015,80(11):M2548-M2554
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. 相似文献
10.
Claudia Ruiz‐Capillas Javier Morales Antonio Moral 《Journal of the science of food and agriculture》2001,81(6):551-558
Whole gutted hake placed in boxes of ice were kept in modified and controlled atmospheres for 12 days with the gas mixture 60%CO2/15%O2/25%N2 (v/v/v) at 2 ± 1 °C. Each lot of hake was then subdivided into two other lots and these were packed on trays, some of them in air and some in the same mixture of gases. The trays were kept at 2 °C until spoilage. The shelf‐life of the hake stored in these conditions was assessed by physical (pH), chemical (TVBN (total volatile basic nitrogen) and TMA‐N (trimethylamine nitrogen)) and sensory (inspection and taste panel) analyses. The results of these analyses indicated that the control lot (stored in air throughout) was rejected before the lots kept in adjusted atmospheres. However, the taste panel accepted all the lots, including the control lot, after 24 days of storage. The sample which was kept at 2 °C in a controlled atmosphere for 12 days and then packed in a modified atmosphere of the same gas mixture did not exceed pH 7 after 31 days of storage, nor the limits of TVBN and TMA‐N of 40 and 12 mg per 100 g respectively. As regards oxidative rancidity, TBA (2‐thiobarbituric acid) levels were very low under all storage conditions and did not exceed 2.5 mg malonaldehyde per 100 g muscle. According to the results of this study, bulk storage of whole gutted hake in boxes in ice under a controlled atmosphere could be combined with later packaging in a modified atmosphere on trays stored at 2 °C to extend the shelf‐life of the hake. © 2001 Society of Chemical Industry 相似文献
11.
Fresh produce can be a vehicle for the transmission of pathogens capable of causing human illnesses and some of them can grow on fresh-cut vegetables. The survival and growth of Escherichia coli O157:H7, Salmonella spp. and Listeria monocytogenes inoculated onto shredded lettuce was determined under modified atmosphere packaging conditions, at various storage temperatures. We also monitored changes in pH and gas atmospheres within the packages and the growth of psychrotrophic and mesophilic microorganisms. After pathogen inoculation, shredded lettuce was packaged in films of different permeability and stored at 5 and 25 °C. After 10 days at 5 °C populations of E. coli O157:H7 and Salmonella decreased approximately 1.00 log unit while L. monocytogenes increased about 1.00 log unit, in all package films. Moreover, the pathogens level increased between 2.44 and 4.19 log units after 3 days at 25 °C. Psychrotrophic and mesophilic bacteria had similar growth at both temperatures with higher populations in air than in the other atmospheres. The composition of the storage atmosphere within the packaging of lettuce had no significant effect on the survival and growth of the pathogens used in this study at refrigeration temperatures. The results obtained can be considered as a warning indicator, which reinforces the necessity for corrective measures to avoid contamination of vegetables. 相似文献
12.
Mexis SF Riganakos KA Kontominas MG 《Journal of the science of food and agriculture》2011,91(4):634-649
BACKGROUND: The present study investigated the effect of irradiation, active and modified atmosphere packaging, and storage conditions on quality retention of raw, whole, unpeeled almonds. Almond kernels were packaged in barrier and high‐barrier pouches, under N2 or with an O2 absorber and stored either under fluorescent lighting or in the dark at 20 °C for 12 months. Quality parameters monitored were peroxide value, hexanal content, colour, fatty acid composition and volatile compounds. Of the sensory attributes colour, texture, odour and taste were evaluated. RESULTS: Peroxide value and hexanal increased with dose of irradiation and storage time. Irradiation resulted in a decrease of polyunsaturated and monounsaturated fatty acids during storage with a parallel increase of saturated fatty acids. Volatile compounds were not affected by irradiation but increased with storage time indicating enhanced lipid oxidation. Colour parameters of samples remained unaffected immediately after irradiation. For samples packaged under a N2, atmosphere L* and b* values decreased during storage with a parallel increase of value a* resulting to gradual product darkening especially in irradiated samples. CONCLUSION: Non‐irradiated almonds retained acceptable quality for ca. 12 months stored at 20 °C with the O2 absorber irrespective of lighting conditions and packaging material oxygen barrier. The respective shelf life for samples irradiated at 1.0 kGy was 12 months packaged in PET‐SiOx//LDPE irrespective of lighting conditions and 12 months for samples irradiated at 3 kGy packaged in PET‐SiOx//LDPE stored in the dark. Copyright © 2010 Society of Chemical Industry 相似文献
13.
Carina Parentelli Gastón Ares Mauricia Corona Claudia Lareo Adriana Gámbaro Matilde Soubes Patricia Lema 《Journal of the science of food and agriculture》2007,87(9):1645-1652
The aim of the present work was to study the influence of modified‐atmosphere packaging on the microbiological and sensory quality of shiitake mushrooms (Lentinula edodes). Mushrooms were packaged under atmospheric air (passive modified atmosphere) and an initial gas mixture of 5% O2 and 2.5% CO2 (active modified atmosphere), in bags of two different films: low‐density polyethylene (PE) and polypropylene (PP). As control, mushrooms were packaged in macroperforated PP films. Bags were stored at 5 °C for 20 days. Package atmosphere composition, mushroom respiration rate, weight loss, microbiological counts and sensory quality were determined during storage. Risk assays were also performed. Under the studied conditions, shiitake mushroom deterioration was not due to microorganism growth, and therefore the shelf‐life of this product might be defined by changes in its sensory characteristics. Sensory analysis showed that mushrooms stored under modified atmosphere (active and passive) had a higher deterioration rate than those stored in PP macroperforated films, and lower sensory quality values during the entire storage time. These results suggest that mushroom deterioration was probably due to shiitake mushrooms' sensitivity to high CO2 concentrations. Copyright © 2007 Society of Chemical Industry 相似文献
14.
Eva Almenar Valeria Del‐Valle Pilar Hernández‐Muñoz José M Lagarón Ramón Catalá Rafael Gavara 《Journal of the science of food and agriculture》2007,87(10):1931-1939
Wild strawberries (Fragaria vesca L.) are high‐added‐value fruits but their marketing is complex owing to their short postharvest life. In this work, equilibrium modified atmosphere packaging (EMAP) technology was used to maintain their quality and consequently to extend their life. Fresh strawberries were packaged with two continuous and three microperforated films (with different gas permeabilities) with the purpose of obtaining equilibrium atmospheres of diverse compositions. Weight loss, pH and acidity, solid content, colour, firmness, fungal decay and development of off‐flavours were selected to monitor fruit quality during 6 days at 10 °C. Among the five packages tested, microperforated films with one and three perforations provided adequate CO2 and O2 equilibrium concentrations in view of the evolution of chemical and physical quality parameters. These results were confirmed by sensory analysis. Copyright © 2007 Society of Chemical Industry 相似文献
15.
Susana Sanz Carmen Olarte J Federico Echávarri Fernando Ayala 《Journal of the science of food and agriculture》2007,87(2):266-273
The impact of minimal processing technology on the sensory quality and the growth of micro‐organisms in eight varieties of cauliflower packaged in four different films (one PVC and three P‐Plus) was measured and quantified during more than 25 days of storage at 4 °C. Other important parameters such as weight loss and gas concentration in the packages were also determined. The composition of the atmosphere in the packages of minimally processed cauliflower depended on both the permeability of the film used for the packaging and the variety of cauliflower. When establishing shelf‐life, loss of sensory quality was the deciding factor rather than loss of microbiological quality. The initial microbial load proved more important than the composition of the atmosphere inside the packages. In sensory evaluation the most important aspect was colour. In instrumental evaluation, coordinate b* was the main means of estimating shelf‐life. The combination of P‐Plus 120 film and varieties of cauliflower of large size and great vigour allowed the atmosphere inside the packages to have an O2 level below 10% and a CO2 level above 10%. That atmosphere composition proved essential for maintaining the sensory quality of minimally processed cauliflower. In these conditions, samples attained a shelf‐life of more than 25 days. However, the different behaviours of the cauliflower varieties make it necessary to establish particular packaging conditions. The use of less permeable films than those used in this study, or the use of actively modified atmospheres, could be an alternative for those varieties that require special packaging conditions when processed using this technology. Copyright © 2006 Society of Chemical Industry 相似文献
16.
Adriana Contreras‐Oliva María B. Pérez‐Gago Lluís Palou Cristina Rojas‐Argudo 《International Journal of Food Science & Technology》2011,46(3):612-619
Citrus fruits are a rich source of vitamins and polyphenolic compounds with antioxidant capacity that need to be maintained during postharvest storage. The aim of this study was to determine the effect of two innovative quarantine treatments, such as insecticidal atmospheres (IA) (95% CO2 and balance air) applied at 20 or 25 °C for 20 h and low doses X‐ray irradiation (0, 30, 54 and 164 Gy), in combination with short periods of cold‐quarantine storage on the nutritional quality of ‘Clemenules’ mandarins. Mandarins were stored at 1.5 °C for 6, 9 or 12 days before the application of IA treatments or for 0, 6 or 12 days after the X‐ray radiation. Nutritional quality of mandarins was determined after the corresponding combination of quarantine treatment (IA or X‐ray) with cold quarantine followed by a shelf life period of 7 days at 20 °C to simulate shelf life conditions. Cold quarantine treatment combined with IA or with X‐ray radiation did not affect negatively total antioxidant capacity and total ascorbic acid content of ‘Clemenules’ mandarins. However, flavanone glycosides (FGs) and total phenolics content were slightly modified. Application of the IA at 20 °C induced a greater inhibition of the FGs than application at 25 °C. When X‐ray irradiation was applied without a previous quarantine period the synthesis of the FGs increased as irradiation dose increased. 相似文献
17.
Survival and Growth of Listeria monocytogenes and Yersinia enterocolitica in Pork Chops Packaged under Modified Gas Atmospheres 总被引:1,自引:0,他引:1
Listeria monocytogenes Scott A, serotype 4b, and Yersinia enterocolitica from vacuum-packaged pork were inoculated onto fresh pork chops. Survival and growth were determined in different atmospheres at 4 °C during 35-days. Atmospheres were gas mixtures [20/0/80, 40/ 0/60, and 40/10/50 (CO2/O2/N2)], vacuum and air. In air L. monocytogenes and Y. enterocolitica grew slower than psychrotrophic spoilage flora. In gas atmospheres, Y. enterocolitica grew at the same rate as psychrotrophic spoilage flora and L. monocytogenes grew more slowly. When 10% O2 was included in the 40% CO2 mixture, growth was reduced. Vacuum packaging was no more effective than gas mixtures in retarding growth. Modified atmospheres provide an environment in the package that would allow growth of Y. enterocolitica and potentially compromise safety of meat products. 相似文献
18.
《Food microbiology》2000,17(4):407-414
This study evaluated the shelf-life quality of Cameros cheeses packaged under modified atmospheres. Five different modified atmosphere conditions were studied (carbon dioxide/nitrogen mixtures and vacuum). Control cheeses were packaged in air. The product stored at 3–4°C was evaluated periodically to investigate its sensory quality, microbiological condition and physicochemical characteristics. Weight loss and pH evolution were similar in vacuum and air packaging. Cheeses packaged in 100% CO2showed the greatest weight losses and lower pH values. CO2reduced proteolysis and lipolysis during storage in all conditions studied. Fat acidity and NPN/TN values were slightly higher in vacuum than in CO2, but lower than in air. Modified atmosphere packaging presented an extended shelf life. Those containing CO2reduced the growth rate of mesophiles, psychrotrophs, Enterobacteriaceae and coliforms, which was lower when the CO2concentration increased. The lowest microbial counts were at 100% CO2while vacuum conditions presented microbial counts only slightly lower than the controls. Salmonella spp.,Staphylococcus aureus and Listeria spp. were not found in any of the samples. Faecal coliforms, moulds and yeasts were not detected under CO2atmospheres or in vacuum. After 7 days of storage, the sensory characteristics of the control cheeses were unacceptable in all the parameters studied. However, the overall score for cheeses stored in 40% and 50% CO2did not change substantially, retaining a reasonable acceptability until the end of the storage period. The 100% CO2atmosphere had a very negative effect on sensory quality. With regard to Cameros cheese, packaging in 50%CO2/50%N2and 40%CO2/60%N2are the most effective for extending shelf life and retaining good sensory characteristics. 相似文献
19.
Ultraviolet‐C Light Sanitization of English Cucumber (Cucumis sativus) Packaged in Polyethylene Film
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Tarek R. Abdussamad Barbara. A. Rasco Shyam S. Sablani 《Journal of food science》2016,81(6):E1419-E1430
Food safety is becoming an increasing concern in the United States. This study investigated the effects of ultraviolet‐C (UV‐C) light as a postpackaging bactericidal treatment on the quality of English cucumber packaged in polyethylene (PE) film. Escherichia coli k‐12 was used as a surrogate microbe. The microbial growth and physical properties of packaged cucumbers were analyzed during a 28‐d storage period at 5 °C. Inoculating packaged cucumbers treated at 23 °C for 6 min with UV‐C (560 mJ/cm2) resulted in a 1.60 log CFU/g reduction. However, this treatment had no significant effect (P > 0.05) on the water vapor transmission rate or oxygen transmission rate of the PE film. Results show that UV‐C light treatment delayed the loss of firmness and yellowing of English cucumber up to 28 d at 5 °C. In addition, UV‐C light treatment extended the shelf life of treated cucumber 1 wk longer compared to untreated cucumbers. Electron microscopy images indicate that UV‐C light treatment influences the morphology of the E. coli k‐12 cells. Findings demonstrate that treating cucumbers with UV‐C light following packaging in PE film can reduce bacterial populations significantly and delay quality loss. This technology may also be effective for other similarly packaged fresh fruits and vegetables. 相似文献
20.
Ioannis S. Arvanitoyannis Ebrahim M. Khah Evangelia C. Christakou & Fotios A Bletsos 《International Journal of Food Science & Technology》2005,40(3):311-322
The physico‐chemical parameters (pH, mechanical firmness and vitamin C) and sensory parameters of grafted and ungrafted eggplant plants were studied in relation to storage time (up to 17 days at 10 °C). Eggplant plants of cultivar ‘Tsakoniki’ were grafted on Solanum torvum and S. sisymbriifolium rootstocks in order to avoid the soil borne disease caused by Verticillium dahliae. The fruits were stored under modified atmosphere packaging (MAP). Vitamin C was negatively affected by grafting it storage, while MAP prolonged the shelf life. Although pH was not affected by grafting but was positively affected by MAP. Flesh firmness was negatively affected by grafting and reduced over storage, but positively affected by MAP. Sensory analysis showed higher ratings of fruits from ungrafted plants for sweetness, acceptance and hardness whereas no difference was detected for overall acceptance. Fruits stored under MAP were better maintained compared with those stored in air. 相似文献