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1.
《Food Control》2014
The effects of severity of slicing and peeling, and of storage atmosphere and temperature on the survival of Escherichia coli O157:H7 at and below the cut surfaces of fresh-cut carrot discs were determined. Slicing with a blunt machine blade enhanced penetration of E. coli O157:H7 and its subsequent survival during storage at 8 °C. Significantly (P < 0.05) higher numbers of cells (0.5 log CFU g−1) penetrated deeper (475–500, 725–750 and 975–1000 μm) into carrot tissue sliced with a blunt machine blade compared to those sliced with a razor blade. Counts on Day 3 and Day 5 of storage remained higher in carrot tissue sliced with a blunt machine blade at all depths sampled. There were no significant effects of peeling method on penetration and survival. Storage of carrot slices in sub-optimal atmospheres (20%CO2/1%O2 resulted in increased survival of cells at the surface and within the tissue compared to storage in more optimal atmospheres (5% CO2/3% O2). Increasing storage temperature from 4 to 10 °C resulted in growth of E. coli O157:H7 at all sample depths. For all experiments, E. coli O157:H7 cells colonising the surface generally survived better than cells that penetrated into the tissue. The data are relevant to improving microbial safety in the fresh-cut sector by demonstrating that cutting with sharp blades (e.g. during harvesting and processing) reduces the depth of potential contamination by E. coli O157:H7. This may also have implications for more efficient anti-microbial dipping and reduced pathogen survival during storage. 相似文献
2.
《Food Control》2016
Modified atmosphere packaging (MAP) based on carbon dioxide (CO2) – nitrogen (N2) gas mixtures has been applied to maintain the safety and quality of ready-to-eat (RTE) meat products. The use of argon (Ar) gas as a supplement to CO2–N2 mixtures or as substitute for N2 is a current approach to enhance the effectiveness of MAP. As there is limited information on the effect of Ar MAP on the growth behaviour or the survival of pathogenic bacteria in RTE foods, the aim of the present study was to assess the influence of Ar in MAP on the growth of Listeria monocytogenes and Escherichia coli strains under different conditions. For this purpose, a CO2–N2 (20:80) atmosphere was compared with a CO2–N2–Ar (30:30:40) and CO2–Ar (30:70) atmosphere based on the assessment of bacterial growth (δ) on a gelatin-agar medium and ham. Additionally, a shelf life monitoring study was performed to evaluate the effect of these treatments on the background microflora of ham. The findings suggest that under the CO2–N2 MAP the product matrices supported the growth (δ > 0.5 log CFU g−1) of L. monocytogenes throughout an observation period of 21 days at 4 ± 2 °C. On the contrary, both MAP containing Ar were equally able to reduce the δ below 0.5 log CFU g−1. In this regard it was irrelevant whether L. monocytogenes was inoculated in depth (per slice) or at the surface (top slice) of the ham. Regarding the influence of the different gas atmospheres on E. coli all gas mixtures applied had the capacity to reduce the δ of E. coli below −0.5 log CFU g−1. Further, shelf-life extension could not be managed with the gas atmospheres considered. 相似文献
3.
《Food Control》2015
The antibacterial activity of modified chitosan-based coatings containing nanoemulsion of essential oils (EOs), gamma irradiation, modified atmosphere packaging (MAP), alone or in combinations, against Escherichia coli O157:H7 and Salmonella Typhimurium was evaluated on inoculated green bean samples. Firstly, four different nanoemulsions, made of carvacrol, mandarin, bergamot and lemon Eos, respectively, were compared in terms of minimum inhibitory concentration (MIC) against the two bacteria evaluated in vitro using the micro-broth dilution method. Carvacrol nanoemulsion resulted to be the most effective antibacterial agent and was therefore selected to be incorporated into modified chitosan (MC) to form a bioactive coating. Secondly, the radiosensitivity of E. coli and S. Typhimurium to gamma irradiation was evaluated on inoculated green beans after coating deposition and MAP. Results showed that, without MAP, MC-based coating containing carvacrol nanoemulsion significantly increased the radiosensitization of E. coli and S. Typhimurium by 1.32-fold and 1.30-fold, respectively. Remarkably, the use of bioactive coating under MAP caused a synergistic effect with an increase in radiosensitivity by 1.80-fold and 1.89-fold for E. coli and S. Typhimurium, respectively. Thirdly, the antibacterial effects of the antimicrobial coating, gamma irradiation, MAP alone and their combinations were evaluated against these two bacteria during a 13-days storage of green beans at 4 °C. Bioactive coating deposition or gamma irradiation treatment resulted effective in controlling the growth of the two bacteria during the entire shelf-life. Moreover, it was also found that the combined treatment of antimicrobial coating, gamma irradiation and MAP caused the reduction of microbial population to undetectable levels during the whole storage period for E. coli and from day 7 to the end of storage for S. Typhimurium. The obtained results can be interested to food companies aiming to ensure the food safety with a prolonged shelf life. 相似文献
4.
《Food Control》2016
As a Portuguese dessert, fios de ovos (literally meaning ‘egg wires’, known in Thai as foi thong (literally meaning ‘golden strands’), is classified as an auspicious Thai dessert and frequently catered in auspicious occasion such as marriage ceremony and ordain ceremony. Due to its great taste, aroma, and appearance, it is popular among Portuguese, Brazilian, Spanish, Indian, Japanese, Malaysian and Cambodian as well as Thai people. Fios de ovos is also recognized as a premium dessert. The objective of the present study was to determine the effect of active packaging (AP) and modified atmosphere packaging (MAP) on the quality of fios de ovos during storage. It was packaged in active oxygen scavenging and modified atmosphere packaging (60% CO2/40% N2) in comparison with conventional air packaging, stored at ambient conditions. During storage, water activity, moisture content, pH, headspace gas composition, total aerobic mesophilic bacteria count, yeasts and molds count and sensory analysis in overall preference score were monitored. Those packaged in air exhibited visible mold growth after 3 days, while those in active and modified atmosphere packaging remained mold-free even after 20 days. With the overall preference criteria and trace amounts of oxygen, the observed shelf life of fios de ovos was found to be 15 days, 6 days and less than 4 days in AP, MAP and air packaging, respectively. Thus, the use of an oxygen scavenger sachet for packed fios de ovos could ensure a 2 week mold-free irrespective of initial contamination and satisfactory according to sensory evaluation and concern of the anaerobic microorganisms. The prolongation in shelf life may allow transportation of this product to a wider area, in turn, increasing market size, and improve consumer confidence, as well as minimize unsatisfied product return. In addition, shelf life extension could be longer than 2 weeks if minimization of initial microbial load has been achieved by good manufacturing practice (GMP). 相似文献
5.
The ordered, mesoporous silica structures MCM-41 and SBA-15 were synthesized as potential vectors for the controlled release of allyl isothiocyanate. The average pore diameter of each silica was 2.45 ± 0.25 nm and 7.28 ± 0.50 nm, however the average pore volume across both samples was 0.817 ± 0.010 mL/g. The maximum loading was 95.3% and 93.9%; the wider pore size of SBA-15 ensured 80% of the available allyl isothiocyanate was released in the first 24 h whereas MCM-41 released approximately 1%/h up to 60 h. Antimicrobial tests were made against 8 microorganisms: Bacillus cereus, Listeria monocytogenes Staphylococcus aureus, Escherichia coli 25922, Salmonella Typhimurium, Vibrio parahaemolyticus, Pichia anomola and Schizosaccharomyce pombe. Controlled release and antibacterial activity from SBA-15 was always superior to those from MCM-41. Overall, allyl isothiocyanate released from the porous vectors was more efficient in controlling yeast and gram-negative bacteria than gram-positive bacteria. In comparison with evaporated liquid allyl isothiocyanate, no apparent loss of activity occurred as a consequence of adsorption and desorption processes in the pore network. 相似文献
6.
《Food Control》2017
The objective of the present study was to determine the shelf-life of minimally-processed fresh-cut apples treated with anti-browning agents under modified atmosphere packaging. Shelf-life is calculated by application of mathematical models with product quality attributes such as: pH; soluble solids content (SSC); CIELab color parameters; sensory evaluation; and microbial spoilage (Salmonella spp., Staphylococcus aureus, Sulfite-Reducing Clostridium, Enterobacteriacae, Escherichia coli, Aerobic mesophilic bacteria (AMB), yeast, mold, Listeria monocytogenes). Golden Delicious and Cripps Pink apple cultivars were individually treated with one of several anti-browning treatments and packaged in a modified atmosphere (N2 = 90.5%; CO2 = 2.5%; O2 = 7%), and stored at 4 °C. The treatments were; 1) non-treated (control); 2) dipping in a mixture of ascorbic and citric acids for 3 min with and without ultrasound (40 kHz, 3 min) treatment; and 3) Ca-ascorbate with/without ultrasound (40 kHz, 3 min) treatment. Results revealed that Cripps Pink was the most suitable variety for minimally-processed fresh-cut product. All the investigated treatments were equally effective in improving the quality of the product compared to the control. Shelf-life predictive models were developed based on the following quality attributes: apple cultivar, anti-browning treatment, color parameters, sensory evaluation, pH, and SSC. Maximum growth rates for Enterobacteriacae and Aerobic mesophilic bacteria were 0.25 ± 0.02 log CFU/g/day and 0.46 ± 0.02 log CFU/g/day, respectively. In order to optimize fresh-cut production, these models can be useful tool for predicting the longest shelf-life time with monitoring microbial activity during production. All models are freely available on-line (“Anti-browning Apple Calculator – C.A.P.P.A.B.L.E.©”; apple.pbf.hr or 31.147.204.87). 相似文献
7.
《Food Control》2015
This study was conducted to investigate the antibacterial effects of various essential oils (EOs) against pathogens using the disc volatilization method. Also, combined effects of EOs in vapor phase and MAP were evaluated for reducing levels of total mesophilic microorganisms on fresh cabbage. The vapor phase activities of EOs (thyme-1, oregano-1, lemongrass-1, and lemongrass-2 oils) observed strong inhibitory effects. The MAP results showed that 100% CO2 gas packaging reduced significantly levels of total mesophilic microorganisms on cabbage and radish sprouts, and their reduction level was 1.55 and 2.26 log10 CFU/g compared to control after 21 days of storage (p ≤ 0.05). Based on previous results, combined effects of EOs in vapor phase and MAP (100% CO2) showed that lemongrass-2 oil with 20 discs showed complete inactivation by <1.0 log10 CFU/g after 14 days of storage. These results could provide useful information for developing alternative preservation method to improve the freshness and shelf-life of fresh produce using natural antimicrobials. 相似文献
8.
《Food Control》2016
The effects of UV-C radiation, modified atmosphere packaging (MAP) and their combination on rainbow trout (Oncorhynchus mykiss) fillets quality were examined during a period of 22 days. The samples were submitted to five packaging conditions: (AP) aerobic packaging; (VP) vacuum packaging; (VP + UV-C) vacuum packaging + UV-C radiation; (MAP) modified atmosphere packaging (80% CO2/20% N2) and (MAP + UV-C) modified atmosphere packaging + UV-C radiation (80% CO2/20% N2; 106.32 mJ/cm2) and storaged at 4 °C. The samples were analyzed daily for microbiological (mesophilic, psychrotrophic and Enterobacteriaceae counts) and chemical (pH, TMA-N, TBV-N, lipid oxidation, ammonia and biogenic amines) parameters. Overall, UV-C radiation promoted lag phase formation in mesophilic and psychrotrophic groups. Mesophilic and psychrotrophic groups presented significant lower (P < 0.05) growth rate and colony forming units in the stationary phase in the samples submitted to MAP. MAP significantly reduced (P < 0.05) total mesophilic count and MAP + UV-C total mesophilic and psychrotrophic counts. Values of pH decreased at all packaging conditions except in the case of aerobic packaging. TBARS value increased faster in samples subject to MAP and MAP + UV-C whereas TMA-N, TVB-N and ammonia values increased slowly. Lower production of putrescine and cadaverine was observed in MAP and VP samples. MAP reduced total production of ammonia, TVB-N and putrescine, whereas MAP + UV-C reduced total production of TVB-N and cadaverine during entire the storage time. Results of the current study suggest that MAP retarded microbial growth and delayed chemical changes enhancing the shelf life of rainbow trout fillets at least twice. 相似文献
9.
《Food Control》2015
The combined effect of weakly acidic electrolyzed water (WAEW) ice-glazing and modified atmosphere packaging (MAP) treatment on the quality of pacific white shrimp (Litopenaeus vannamei) during frozen storage was investigated in terms of microbiological activity, TVBN, TMA and TBARS content, texture, color and volatile flavor analysis. As a result, significantly (p < 0.05) higher inhibitor effects on total aerobes and Staphylococcus aureus were observed in WAEW ice-glazed shrimp packaged in 40% CO2 + 10% O2 + 50% N2 or in 30% CO2 + 20% O2 + 50% N2 than the water- and WAEW ice-glazed batches. Additionally, chemical analysis results showed that WAEW ice-glazing combined with MAP was highly effective in maintaining lower TVBN, TMA and TBARS values in frozen shrimp, perhaps due to the synergistic effect of antibacterial and antioxidant abilities. On the other hand, the texture, L*, and a* results also confirmed that this combined treatment effectively retarded the degradation of the physical structure of shrimp muscle and showed a positive effect on the stability of color during frozen storage. However, the presence of WAEW ice-glaze showed a negative effect on the volatile flavor of thawed shrimp due to the volatile chlorine and chlorine dioxide, but no significant effect in the cooked samples. Overall, the application of WAEW ice-glazing combined with MAP on peeled frozen shrimp is advisable to achieve better quality maintenance and extend the shelf-life of refrigerated products. 相似文献
10.
《Food Control》2017
Minimally processed fresh-cut (MPFC) fruit products are an important source of functional ingredients, and increased consumers’ demand boosted an expansion of this segment of food industry. Apples (Malus sp.) are commonly cultivated fruits and processed to MPFC products. Their low shelf life is the main obstacle for gaining maximum nutritive and economic benefits. Enzymatic, metabolic, and other physiological processes induce changes that render the product spoiled and decrease the storage and marketability life of MPFC fruits. Such spoilage can be controlled by modified atmosphere packaging (MAP), but intrinsic influences of numerous MAP factors are not clearly elucidated. Microbial growth adds another layer of complexity to MAP. Mathematical modeling can successfully predict microbial growth and spoilage, hence saving production cost and provide better control over the production chain. In this sense, this review provides an overview of MAP’s factors that influence the quality of stored MPFC products. Focus was placed on apples and development of mathematical models that can be useful for prediction of their spoilage during storage and subsequently their shelf-life. 相似文献
11.
《Food Control》2014,35(2):414-419
The minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) of mustard allyl isothiocyanate (AITC) against five strains each of Salmonella and Listeria monocytogenes individually, and when combined by genus were studied in Mueller-Hinton broth at 21 or 37 °C as well as the interactive effects of pH (5.0–9.0) at temperatures of 4–21 °C on cell viability when held under these conditions for up to 10 d. The stability of 200 ppm AITC was monitored during these trials. The MIC and MBC values of AITC ranged from 60 to 100 ppm and 120–180 ppm, respectively, at 37 °C and ranged from 10 to 40 ppm and 200–600 ppm, respectively, at 21 °C against both pathogens. AITC had no antimicrobial activity at low temperatures (4 or 10 °C) and alkaline pH over 10 d, but at neutral pH, AITC reduced L. monocytogenes by 4.14 and 8.45 log10 CFU/ml at 4 or 10 °C, respectively. At acidic pH, AITC was more effective against Salmonella which was reduced by 2.56 and 6.48 log10 CFU/ml at 4 and 10 °C, respectively. However, AITC was more effective at combinations of 21 °C and neutral pH against L. monocytogenes (cells were not detected at and beyond 3 d) and at combinations of the higher temperature and acidic pH against Salmonella (cells were not detected at and beyond 6 d). Mustard AITC was more stable at low pH and temperature indicating that it can be an effective antimicrobial at combinations of low or neutral pH values and room or refrigerator temperatures (4–10 °C) against these foodborne pathogens. 相似文献
12.
《Food Control》2016
The wild pink salmon (Oncorhynchus gorbuscha) has a great economic importance having a meat quality higher than that of breeding salmons; however, the consumption of wild pink salmons is a public health concern due to the high risk of infection with the third-stage nematode larvae (L3) of the family Anisakidae. Only L3 of Anisakis and Pseudoterranova genera are the causative agents of anisakidosis and allergies, which can be even fatal. The aims of the present work were to investigate the infection prevalence and species identity of Anisakidae larvae in fillets of North Pacific wild pink salmons. A total of 244 samples of frozen fillets, collected between 2009 and 2013, were examined by the artificial digestion method. L3 were detected in 177 (72.5%) fillets. Out of 708 recovered L3, 705 were identified as Anisakis type I and 3 as Pseudoterranova sp. by morphological examination; of these, one L3 from each infected fish, was identified as Anisakis simplex sensu stricto (#174) or as Pseudoterranova decipiens (#3) by PCR-RFLP. Despite the risk of acquiring human anisakidosis is efficiently prevented by fish fillet freezing, our findings highlight how the high prevalence of Anisakidae larvae in frozen fillets of pink salmon, may be the source of allergic reactions in sensitized persons. The increased interest of consumers in the pink salmon may pose considerable food safety problems that merits to be systematically investigated. 相似文献
13.
以固体氯化物为催化剂合成脂肪酸烯丙醇酯的研究 总被引：5，自引：0，他引：5
报道了用多种固体氯化物为催化剂,以脂肪酸和烯丙醇为原料,合成了一系列脂肪酸烯丙醇酯.结果表明,该催化剂腐蚀污染小,后处理容易,可成十倍地缩短酯化时间,提高酯的收率,其催化效果多数优于硫酸和硫酸盐. 相似文献
14.
用DSC分析聚合物对改性沥青性质的影响 总被引：11，自引：2，他引：11
研究了几种改性剂对沥青进行改性前后的ＤＳＣ图谱，指出改性沥青温度敏感性降低主要原因是改性剂改变了沥青组分的相转变温度，降低了相变热。并对几种改性剂改性效果进行了评价。 相似文献
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烯丙醇聚氧烷基醚的浊点及影响因子 总被引：1，自引：0，他引：1
烯丙醇聚氧烷基醚(AAP)是一种非离子表面活性剂。通过实验测定了AAP的浊点,考察了分别添加非离子表面活性剂聚乙二醇（PEG）、离子表面活性剂十二烷基苯磺酸钠(LAS)、极性溶剂醇以及LAS和醇的混合物后,AAP浊点的变化。结果表明,PEG的加入基本不影响AAP的浊点;LAS或LAS与乙醇混合物的加入可改变AAP的浊点。随着LAS、LAS-乙醇混合物的加入,AAP的浊点大幅度上升;随着它们加入量的增加,AAP的浊点进一步提高。添加醇类溶剂后,AAP的浊点随醇的结构和性质的不同而升高或降低。 相似文献
18.
储罐容器的底板角焊缝受交变载荷影响,容易产生疲劳裂纹.受结构限制,储罐底板角焊缝的无损检测方法一般选择渗透检测.由于储罐底板内外部角焊缝受力情况不同,对渗透检测的结果造成一定影响.因此只有选择正确的检测方案,才能达到准确检验大型储罐底板角焊缝目的,为大型储罐的安全运行提供保障. 相似文献
19.
《Food Control》2017
Since the beginning of the current millennium, innovations in food packaging systems have evolved as response to the continuous changes in market trends and consumer’s preferences for convenient, safe, healthy and quality food products. Active packaging (AP) system provides such functionalities to facilitate these demands and offers role beyond the traditional protection and inert barrier to the external environment. Various AP components such as antimicrobials, antioxidants, O2 scavengers, CO2 emitters/absorbers, moisture regulators, flavor releasers, and absorbers have been deliberately included in the package system for augmenting packaging performance. These constituents delay or stop chemical, microbial, enzymatic and oxidative spoilage, control weight loss, retain color and integrity of meat based products. Currently, the use of edible or biodegradable materials, plant extracts and nanomaterials are expected to substitute synthetic additives due to their packaging and waste management notions. This article reviews the principles and technological advances as well as the global patents and future research trends in AP sector with their applications focused on meat products. 相似文献