Quality Changes and Safety Evaluation of Ready-to-Eat Roasted Antarctic Krill(Euphausia superba)During Storage at Room Temperature(25℃)

The objective of this study was to determine the quality changes and shelf life of ready-to-eat roasted Antarctic krill,either untreated(CT)or treated with sodium diacetate(SD)or sodium diacetate and a deoxidizer(SDD),during storage at room temperature(25℃)by using sensory,physiochemical,and microbial assessment.Additionally,fluoride accumulation in this food product was used to evaluate its safety.Analysis showed that the addition of SD and SDD resulted in better sensory scores compared of that of CT samples(P<0.05).Accordingly,microorganism growth and total basic nitrogen(TVB-N)were maintained at a low level for the duration of storage with SD and SDD treatments.The total viable counts of SD and SDD reached(4.58±0.08)log(CFU g^(−1))and(4.20±0.11)log(CFUg^(−1)),respectively.The mold was found after 6 and 18 days for SD and SDD treatment,and the numbers reached 5.2×10^(6) and 8.5×10^(4) respectively at the end of shelf life.The TVB-N values from CT continuously increased during the whole storage.While TVB-N values from SD and SDD remained significantly less change(P<0.05)during the early 20 days of the storage,and the values reached(12.11±0.07)mg(100 g)^(−1) and(10.88±0.15)mg(100 g)^(−1) on day 33 and day 70,respectively.Importantly,SDD treatment effectively minimized the oxidation values and retained the color of ready-to-eat roasted Antarctic krill.Our results showed that the shelf life of ready-to-eat roasted Antarctic krill treated with SDD was extended by up to 52 days.Additionally,rats fed ready-to-eat roasted Antarctic krill showed accumulation of fluoride exclusively in the thighbone.The accumulation of fluoride residues in the thighbone showed concentration-dependent.The concentrations of fluoride residues in rats were(1760.03±38.21),(2371.52±42.15)mgkg^(−1) and(3615.44±30.53)mgkg^(−1),which were less than sodium fluoride feeding group(4621.01±28.67)mgkg^(−1).The results suggested that the SD and SDD treatments led to better quality and shelf life extension of ready-to-eat roasted Antarctic krill during storage at room temperature(25℃).Therefore,the ready-to-eat roasted Antarctic krill can be of great interest to the seafood industry.

Antimicrobial Resistance,Virulence Profile,and Molecular Characterization of Listeria monocytogenes Isolated from Ready-to-eat Food in China,2013-2014

We aimed to investigate the potential pathogenic profile and antibiotic resistance of Listeria monocytogenes isolated from ready-to-eat food in China.Antimicrobial resistance was determined by broth microdilution following the Clinical and Laboratory Standards Institute protocol Molecular serotyping,virulence,and resistance genes were identified using PCR.Multi-locus

Effect of Pre-Processing Steps, Nitrite and Irradiation Combination Preservation of a Ready-to-Eat Spinach Relish and Sorghum Porridge Meal

The effects of pre-processing steps (washing, blanching and cooking) and combination preservation of irradiation (10 kGy) and nitrite (0, 50, 100, 150 and 200 mg·kg–1) on the survival of Clostridium sporogenes spores in a ready-to-eat (RTE) spinach relish and sorghum porridge meal were investigated. Chlorine wash (250 mg–1) reduced the C. sporogenes counts in spinach by 1.6 log cycles. Blanching following the chlorine wash caused no significant decrease in the spore counts in spinach. On the other hand, cooking significantly reduced the counts in the porridge by about 1.7 log cycles. In both components of the meal, there was a significant decrease in the Clostridia counts with increased sodium nitrite levels. However, the counts increased in the sorghum porridge component after 12 d of storage at 10℃. Cooking alone significantly reduced the final nitrite levels in both components of the meal. In both components of the meal, nitrite in combination with irradiation reduced the C. sporogenes counts to less than 10 cfu/g. A safe RTE spinach relish and sorghum porridge meal could be expected when a pre-processing, followed by a combination treatment of at least 50 mg·kg–1 sodium nitrite and a target dose of 10 kGy is applied.

Clostridium difficile in ready-to-eat foods in Isfahan and Shahrekord,Iran

Objective:To determine the prevalence and antimicrobial resistance of Clostridium difficile(C.difficile) isolated from ready-to-eat foods of Iran.Methods:From January to August 2013,a total of 368 unpacked ieady-to-eat food samples were purchased from randomly selected supermarkets,retail stores and restaurants located in Isfahan and Shahrekord,Iran and were evaluated for the presence of C.difficile.Results:C.difficile spores were detected in 5(1.36%) of the 368 samples.The highest prevalence of C.difficile was found in fasl salad(4.29%).followed by yogurt stew(2%),and olovyeh salad(0.93%).All 140 maccaroni salad and I'alafel sandwich samples were negative for C.difficile.One of the five C.difficile isolates(20%) contained tcdA,tcdB and cdtB toxin genes and four strains(80%) contained tcdA.and tcdB toxin genes.Also,among the five C.difficile isolates,only three strains were found to be toxigenic for toxin A and/or B by ELISA.Isolates were susceptible to vancomycin and metronidazole,but variably resistant to other antimicrobial drugs.Conclusions:This study,combined with studies on other food sources,suggests that widespread contamination of food is common.

Fungal Population Dynamics in Ready-to-eat Salads During a Shelf-life in Italy

The aim of this work was to investigate the fungal population dynamics in ready-to-eat bagged samples of rocket （Diplotaxis spp.）, lettuce baby leaf （Lactuca sativa L.） and ＂songino＂ （Valerianella olitoria L.） during a shelf-life, in order to evaluate the effects of the storage length and season of production on the spoilage processes. The incidence of toxigenic moulds was particularity studied in order to evaluate a potential production of mycotoxins and allergenic conidia. A total of 900 samples collected from 10 Italian trademarks were analyzed at the 2nd, 5th and 8th day after the packaging in the spring and summer. A very high number of fungi was found and a great variability of moulds and yeasts at the 1 st day of sampling was observed. Regarding to season of production, any seasonal effect on the moulds and yeasts has been observed, but the moulds detected belonged to different species in relation to season. Regarding to storage length, the yeasts and moulds did not showed significant variations during a shelf-life. In relation to vegetable species, the lettuce resulted always less contaminated with respect to other salads, and the rocket presented 1-2 Log cfu/g of increasing in the level of moulds. Regarding to fungi species, the yeasts were significantly predominant respect to moulds. Finally, the toxigenic moulds Aspergillusflavus and Penicillium italicum were found in all the types of salad in the summer, and their growth during the storage at low temperature represented a potential hazard for the mycotoxins and allergenic conidia production in these commodities.

Effects of γ Irradiation Dose on Sensory Acceptability of a Ready-to-Eat Spinach RELISH and Sorghum Porridge Meal

To establish the highest irradiation dose, which was still organoleptically acceptable for producing ready-to-eat (RTE) sorghum porridge and spinach mor?go meal if irradiation could be used as a preservation method. Study design: In order to produce a safe RTE meal made of these two meal components, a consumer sensory acceptability test was done on the meal irradiated at different doses of 0, 10, 20 and 30 kGy. Place and Duration of Study: Department of Food Science, University of Pretoria, between January 2000 to December 2000. Methodology: A consumer sensory acceptability test was done on the two meal components irradiated at different doses of 0, 10, 20 and 30 kGy. The sensory acceptability test on the appearance, texture, taste, and overall acceptability of the RTE meal components were evaluated. Results: The consumer overall acceptability test results showed that the two components of the meal remained acceptable up to a dose of 10 kGy (p < 0.05). The loss in appearance was observed by the panellists in the two components of the meal where the texture changed with increased irradiation doses (p < 0.05). However, irradiation had less effect on the taste of the spinach than on the sorghum porridge (p < 0.05). Overall, irradiating up to 10 kGy produced a RTE meal with acceptable sensory qualities.

An exploratory study of food safety and food handling: Examining ready-to-eat foods in independent delicatessen operations

The US Center for Disease Control and Prevention (CDC, 2009) reports that each year 76 million cases of foodborne illness occur with over 300,000 people hospitalized and 5000 deaths. This study, phase I of a continuing study, identifies key areas for food safety improvement. This study is designed as an exploratory evaluation of independently owned and operated delicatessen operations, using Escherichia coli and Staphylococcus aureus as indicators to assess food handling and the public’s risk for pathogenic contamination from commonly served ready-to-eat/take-away foods. The analysis consisted of a comprehensive strategy of laboratory testing of samples for pathogenic contamination, informal field observation of food handling procedures, and the examination of the most recent health inspection reports for each of the 18 operations visited. The deli turkey, cream cheese and lettuce were tested using bacteria indicator plates. The results showed widespread levels of contamination. Of the 54 samples tested for Escherichia coli, 26 showed positive results which are ~45% for E. coli contamination. Of the 54 samples tested for Staphy-lococcus aureus, 31 showed positive results which are ~57% for S. aureus contamination. One issue discovered while conducting the study was the lack of consistent uniform international standards of contamination tolerance levels. The informal field observations and health report analyses revealed widespread temperature violations and numerous instances of poor food handling. The study offers independent practitioners a strategy designed to improve their health inspections scores, food handling, and mitigation of operator liability. Independent operators traditionally do not enjoy the resources of centralized supervision and expert on-staff training;yet in aggregate they account for significant volume in both dollars and the quantity of product served. This study adds needed scrutiny to this important food niche.

Effects of Lactobacillus paracasei N1115 on gut microbial imbalance and liver function in patients with hepatitis B-related cirrhosis

BACKGROUND Hepatitis B cirrhosis(HBC)is a chronic disease characterized by irreversible diffuse liver damage and aggravated by intestinal microbial imbalance and metabolic dysfunction.Although the relationship between certain single probiotics and HBC has been explored,the impact of the complex ready-to-eat Lactobacillus paracasei N1115(LP N1115)supplement on patients with HBC has not been determined.AIM To compare the changes in the microbiota,inflammatory factor levels,and liver function before and after probiotic treatment in HBC patients.METHODS This study included 160 HBC patients diagnosed at the General Hospital of Ningxia Medical University between October 2018 and December 2020.Patients were randomly divided into an intervention group that received LP N1115 supplementation and routine treatment and a control group that received routine treatment only.Fecal samples were collected at the onset and conclusion of the 12-wk intervention period.The structure of the intestinal microbiota and the levels of serological indicators,such as liver function and inflammatory factors,were assessed.RESULTS Following LP N1115 intervention,the intestinal microbial diversity significantly increased in the intervention group(P<0.05),and the structure of the intestinal microbiota was characterized by an increase in the proportions of probiotic microbes and a reduction in harmful bacteria.Additionally,the intervention group demonstrated notable improvements in liver function indices and significantly lower levels of inflammatory factors(P<0.05).CONCLUSION LP N1115 is a promising treatment for ameliorating intestinal microbial imbalance in HBC patients by modulating the structure of the intestinal microbiota,improving liver function,and reducing inflammatory factor levels.

Impact of lactic acid bacteria on the control of Listeria monocytogenes in ready-to-eat foods

Due to the increased demand for ready-to-eat(RTE)minimally processed foods,alternatives to chemical and thermal preservation methods to maintain food safety are highly demanded.A significant safety hazard in RTE food products is the growth of the foodborne pathogen Listeria monocytogenes(L.monocytogenes).After processing,recontamination or cross-contamination of L.monocytogenes in RTE food products may occur and the lack of cooking can lead to an increased risk of listeriosis.Further,some RTE food products(e.g.cheese and cured meat)can have a long processing period and shelf life,thus allowing for the growth and proliferation of L.monocytogenes in the food matrix.Lactic acid bacteria(LAB)are generally recognized as safe probiotics and have been proposed as a biological control approach to eliminate foodborne pathogens including L.monocytogenes.LAB have been reported to extend the shelf life of food products and inhibit pathogen proliferation via growth competition and metabolite production.LAB are native microflora of many RTE foods,but only certain LAB may inhibit pathogen growth.Therefore,the specificity of LAB species should be employed in their use in RTE foods.This review will discuss the antimicrobial mechanisms of LAB against L.monocytogenes,selective use of LAB in food matrices,and their uses in food processing and packaging.

Iron and Folate Contents of Tajik Legumes

Seven varieties of Tajik legumes and two Tajik snack type ready-to-eat (RTE) whole/split chickpeas were analyzed for iron in raw and cooked legumes and for naturally occurring folate content in cooked legumes. Iron was measured according to AACC method 40 - 41B. Folate contents were determined by microbiological (Lactobacillus casei subsp. Rhamnosus ATCC 7469) and high-performance liquid chromatography analysis utilizing a tri-enzyme treatment (pro-tease, α-amylase and conjugase). Folate derivatives of tetrahydrofolate, 5-formyl-tetrahydrofolate and 5-methyl- -tetrahydrofolate were identified and quantified. Iron content for Tajik legumes ranged from 5.52 to 13.27 mg/100 g for raw;2.81 to 4.12 mg/100 g for cooked and 4.37 and 4.76 mg/100 g for RTE chickpeas. The total folate content of cooked legumes ranged from 53 to 81 μg/100 g for beans;133 to 203 μg/100 g for peas, and from 39 to 22 μg/100 g for small and large lentils, respectively. The predominant form of folate in legumes was tetrahydrofolate, followed by 5-formyl-tetrahydrofolate and 5-methyl-tetrahydrofolate.

Biochemical Factors Affecting the Quality of Products and the Technology of Processing Deep-Sea Fish, the Giant Grenadier Albatrossia pectoralis

The composition of muscle tissues of a deep-sea species, the giant grenadier(Albatrossia pectoralis), and a mesopelagic species, the Alaska pollock(Theragra chalcogramma), are compared. Grenadier is proved to have a higher moisture content(91.7%) and lower protein(7.4%) and lipid(0.3%) contents. The factors responsible for the softening and moisture separation during processing of grenadier are identified. Contents of some fractions of non-protein nitrogenous components, including trimethylamine oxide(TMAO) and free amino acids, are clarified. The proportion of the main myofibrillar proteins myosin and actin, which is considered as an indicator of efficiency of structure formation in fish muscle tissue during processing, is almost 20% lower in giant grenadier than in pollock. The effects of endogenous protease, Са^2+-ATPase and transglutaminase on the processes of autolysis, denaturation, and possibility of myofibrillar proteins cross-linking were also studied. The proposed technology of getting a nutritionally balanced, gel-like, ready-to-use foodstuff from grenadier fillet includes its enrichment with pollock muscle tissue and supplementing with a binary structure-forming agent containing collagen and chitosan. Nutritional value of the products is assessed by the method of biological assay and by determining the denaturation changes of myofibrillar proteins. The modes of fine mincing and thermal processing, as well as the shelf-life of the finished product are justified. The developed technology of producing a ready-to-eat food from giant grenadier will allow a more efficient use of this underutilized resource.

The Effects of Heat Shock on the D-Values of <i>Listeria monocytogenes</i>on Selected Seafood Matrices

With more ready-to-eat foods and increased shelf-lives, prevention of Listeria monocytogenes contamination has become a necessity for the food industry. This study examined the effects of sublethal heat treatment on the decimal reduction time (D-values) of three L. monocytogenes serotypes (1/2a, 1/2b, 4c), and non-pathogenic L. innocua. The D70 (D-value at 70℃) values of heat-shocked (HS) and non-heat-shocked (NHS) Listeria grown in tryptic soy broth (TSB) were determined. The D70 values of HS L. monocytogenes serotype 1/2a and L. innocua were significantly higher compared to NHS cultures, although by 48 h, the values returned to NHS levels. When HS and NHS 1/2a and 1/2b were inoculated on crab meat and cooked shrimp, the D70 values of HS cultures were at least 2-fold higher, compared to when they were grown in TSB. This increase in heat resistance for the HS cultures may be attributed to the protective effect of the seafood matrix itself.

Development of Blast Chilling Method for Cooked Meat Dishes

In order to ensure hygienic end-product realization, it is necessary as soon as possible to chill it by using efficient methods, such as blast chilling. Blast chill equipment provides food chilling optimum for 90-120 min to ＋3 ℃, reaching an internal temperature of food particularly for the perishable ready-to-eat product groups, including meat dishes, which are used as a reference model in this study. The aim of the research is to reduce duration of the chilling process at the same time providing equipollent microbiological indices of the product to be chilled, which could enable carrying out its storage in a chilled condition for several days. For this study, two types of meat dishes were used---pork goulash and minced meat sauce. Research results show that by combining the food safety standards and cost-efficiency, chilling final temperature of blast chilling was in the range of ＋3 ℃-＋1 1 ℃, followed by further storage in refrigerator. It was recommended to stop the blast chilling at ＋7 ℃＋1 1 ℃ temperature range, depending on the required shelf life for the ready-to-eat product. It is therefore essential to encourage the blast chilling process, reducing its duration and enabling to optimize the overall process.

Microbiological assessment of street foods at the point of sale in Maputo(Mozambique)

Objectives:The aim of this study was to assess the microbiological quality and safety of street food sold in the main streets and informal markets of Maputo,the capital of Mozambique.Materials and Methods:From 83 different vendors selling different types of foods,83 samples of ready-to-eat(RTE)street food were analyzed.Mesophiles,Escherichia coli and total coliforms were used as quality and hygiene indicators.Listeria monocytogenes(L.monocytogenes)Salmonella and coagulase-positive staphylococc were used as food safety indicators.Results:High proportions of unsatisfactory food samples were found in both traditional hot(76.7%)and cold(75%)foods.L.monocytogenes and Salmonella were tested negative in this survey.However,when coagulase-positive staphylococci was used as a food safety indicator,approximately 25%(23/83)of the food samples analyzed were classified as unsatisfactory/potentially hazardous.Conclusions:These results,showing that street food sold in Maputo clearly requires adequate sanitary conditions for its preparation and sale,contribute to the development of good manufacturing practices(GMP)for street food in Maputo,Mozambique.This is the first report on the microbiological quality and safety of street food in Mozambique.

Estimates and burden of foodborne pathogens in RTE beverages in relation to vending practices

Objectives:Growing trend of street-vended food in underdeveloped countries offers low-cost food to many sections of population.Although it provides job opportunities to many urban dwellers,several health hazards are associated with this business.The present study investigates the burden of foodborne pathogens in Ready-To-Eat(RTE)beverages in relation to vending practices among street vendors of Rawalpindi City,Pakistan according to standardized methods and protocols.Materials and Methods:Six densely populated locations of Rawalpindi city were selected.Commonly consumed sugar cane juice(SCJ)and tamarind prune(dried plums)drink(TPD)(locally called as Imli Alu Bukhara sherbet)from five vendors from each location were chosen in summer season where the temperature reaches above 40℃.Mean and the standard deviation were obtained by univariate and bivariate analyses.Association between the study variables was assessed through cross-tabulations,chi-square,and correlation tests.Results:All the samples were found unsatisfactory in comparison to guidelines of aerobic plate count.Total coliform was observed in 86.7 per cent of SCJ and 70.0 per cent of TPD samples.Fourteen samples of SCJ exceeded the limit of>1100 MPN/ml value,whereas samples of TPD exceeded this limit for Escherichia coli.All of SCJ and 93.3 per cent of TPD samples depicted the presence of Salmonella aureus.Salmonella spp.were found significantly high in 73.3 per cent samples of SCJ and 23.3 per cent samples of TPD.Conclusions:The incidence of high bioloads attributes towards a potential reservoir of foodborne pathogens due to unhygienic vending practices.