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 foll...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展开更多
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)...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.展开更多
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 s...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.展开更多
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-ea...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.展开更多
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.）...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.展开更多
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. S...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.展开更多
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 continuin...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.展开更多
Thermal processing causes significant flavor degradation in spice-rich food products like RTE chicken.Therefore,understanding strategies to preserve volatile compounds is crucial.In this study,hydroxypropyl-betacyclod...Thermal processing causes significant flavor degradation in spice-rich food products like RTE chicken.Therefore,understanding strategies to preserve volatile compounds is crucial.In this study,hydroxypropyl-betacyclodextrin(HP-β-CD)was used as a wall material to encapsulate and preserve the selected(clove,cardamom,cinnamon,and black pepper)essential oil blend(1:1:1:1 ratio)in RTE chicken cubes during retort processing for improved flavor retention.For this purpose,the inclusion complex(SME-HP-β-CD)was initially evaluated for its encapsulation efficiency(EE%),crystallinity,morphology,and thermal properties,and was also subjected to simulated saliva to study the release kinetics of flavor compounds from the HP-β-CD encapsulated matrix.It was found that the EE%was 64.35%,with a reduced crystallinity of 38.63%in SME-HP-β-CD compared to pure HP-β-CD,indicating successful encapsulation.No apparent signs of degradation were observed up to 200◦C,suggesting that the encapsulated system is thermally stable.In the case of the simulated salivary study,the Peppas-Sahlin model provided an excellent fit(R^(2)=0.99)for all the target volatiles(1,8-cineole,linalool,cinnamaldehyde,and linalool),confirming a diffusion-controlled release mechanism(n=0.25).The thermally stable SME-HP-β-CD was incorporated into RTE chicken cubes,subjected to retort processing(F_(0)=4.0 min),and analyzed for flavor composition.Headspace GC-MS revealed up to 13.64%reduction in hexanal in SME-HP-β-CD incorporated chicken cubes(CCU-SME-AP).PCA biplots of E-nose data confirmed distinct clustering from the control.Therefore,HP-β-CD encapsulation effectively preserves flavor and oxidative stability in retort-processed RTE chicken cubes.展开更多
Effects of modified atmosphere packaging(MAP)combined with epigallocatechin gallate(EGCG)on quality changes of ready-to-eat harpiosquillid mantis shrimp meat(RTE-MSM)during refrigerated storage at 4℃for 24 days were ...Effects of modified atmosphere packaging(MAP)combined with epigallocatechin gallate(EGCG)on quality changes of ready-to-eat harpiosquillid mantis shrimp meat(RTE-MSM)during refrigerated storage at 4℃for 24 days were investigated.Samples were treated with EGCG at 0,200,and 400 ppm before being packaged in air or under MAP1(60%CO_(2)/10%O_(2)/30%Ar),or MAP2(80%CO_(2)/10%O_(2)/10%Ar).The control(packaged in air without EGCG)showed rapid microbial growth,with total viable counts exceeding acceptable limits of 5 log CFU/g on day 9.MAP significantly inhibited microbial proliferation(P<0.05),in which MAP2 exhibited higher efficacy than MAP1.The inhibitory effect was enhanced by EGCG in a concentration-dependent manner.Chemical spoilage indicators,including pH,total volatile basic nitrogen,trimethylamine nitrogen contents,peroxide value,and TBARS,increased during storage but were markedly reduced by MAP in combination with EGCG,especially at 400 ppm.Protein degradation,exudate loss,and texture softening were significantly retarded in MAP+EGCG treated sample.Additionally,MAP combined with EGCG preserved polyunsaturated fatty acids(EPA and DHA),retarded texture softening,and impeded the formation of spoilage-related volatile compounds.Principal component analysis(PCA)biplots,correlation heatmap and hierarchical clustering ana-lyses also confirmed the relation between the microbial growth,chemical quality indices,volatile compounds and fatty acid changes.Overall,MAP2 combined with 400 ppm EGCG was the most effective treatment,main-taining quality and extending the refrigerated shelf life of RTE-MSM to 21 days,demonstrating the potential of this multi-hurdle strategy for preserving ready-to-eat crustacean products.展开更多
Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization.In this study,the combined dealumination and sterilization by slightly acidic electrolyzed water(SAE...Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization.In this study,the combined dealumination and sterilization by slightly acidic electrolyzed water(SAEW)were used to produce ready-to-eat jellyfish.The optimal aluminum removal amount reaching 120.17 mg/kg was obtained after response surface analysis.Structure observation through optical microscope after Masson staining and scanning electron microscope showed that the microstructure of jellyfish was not destroyed after SAEW treatment.The increase of total plate count(TPC)and pH value during storage was significantly inhibited by SAEW,while the other properties did not changed significantly.Staphylococcus,especially Staphylococcus epidermidis was dominant in the ready-to-eat jellyfish and many spoilage bacteria were inhibited by SAEW.The correlation network maps showed that Pseudomonas and Shewanella contributed most to the increase of TPC and pH value in the control group,while the correlated microbial genera mainly changed to Acinetobacter,Cutibacterium,and Pseudomonas after SAEW treatment,resulting in the decrease of hardness and chewiness of ready-to-eat jellyfish during storage.The inhibited Pseudomonas contributed most to the decrease of TPC and pH value after SAEW treatment.This study provides a novel technology of dealumination and sterilization for ready-to-eat jellyfish.展开更多
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 ...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.展开更多
The protective effects of molecular crosslinked ready-to-eat sea cucumber(RSC)against immunosuppression induced by cyclophosphamide in mice were investigated.After gavage of molecular crosslinked RSC,the SIgA levels o...The protective effects of molecular crosslinked ready-to-eat sea cucumber(RSC)against immunosuppression induced by cyclophosphamide in mice were investigated.After gavage of molecular crosslinked RSC,the SIgA levels of intestinal mucosa in mice were significantly increased by 31.6%(P<0.01),and the terminal differentiation of IgA+B cell was promoted with the significant up-regulation of IL-6 and IL-10 levels.Moreover,the secretion mechanism of plasma cell was mainly promoted through XBP-1s pathway mediated by IRE1(P<0.01),rather than ATF-4 and ATF-6 pathway(P>0.05).In addition,the diversity of intestinal flora was increased,and the imbalance of intestinal flora was improved.The Lachnospiraceae_NK4A136_group dominated in crosslinked group could promote the repair of intestinal mucosa.Therefore,molecular crosslinked RSC can alleviate the intestinal mucosal damage via promoting SIgA secretion and regulating gut microbiota of mice.展开更多
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...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.展开更多
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 wa...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.展开更多
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 h...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.展开更多
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 t...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.展开更多
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 ...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.展开更多
Listeria monocytogenes is a resilient foodborne pathogen that forms biofilms,allowing it to persist and thrive in food-processing environments.This study examined the structural characteristics of biofilms formed by t...Listeria monocytogenes is a resilient foodborne pathogen that forms biofilms,allowing it to persist and thrive in food-processing environments.This study examined the structural characteristics of biofilms formed by three L.monocytogenes strains,their transfer to cold-smoked rainbow trout fillets,and the bioprotective effects of two lactic acid bacteria(LAB)cocktails during storage.Confocal microscopy revealed that mixed-strain biofilms exhibited more homogeneous structures than single-strain biofilms,emphasizing their relevance in contamina-tion events.Transfer experiments demonstrated that 87.52%of L.monocytogenes biofilm cells were transferred from stainless steel to cold-smoked rainbow trout fillets after 90 s of contact,highlighting a significant contamination risk.The commercial LAB cocktail containing Lactococcus lactis subsp.lactis and Leuconostoc carnosum effectively inhibited L.monocytogenes growth under both static(5◦C)and dynamic(4-20◦C)conditions,reducing bacterial concentrations by>0.70 and>1.24 log CFU/g respectively,after 21 days.The inhibitory effect was likely driven by bacteriocin production,particularly leucocin,potentially enhanced by diacetyl production.LAB-based bioprotection effectively controlled L.monocytogenes without producing significant changes in pH or water activity.These findings highlight the need for multi-strain biofilm models to better understand contamination dynamics and support LAB-based bioprotection as a natural,effective strategy for improving food safety in smoked fish products.展开更多
Meat products are classified as perishable foods and have favourable conditions for the multiplication of microorganisms such as Listeria monocytogenes,an important pathogen associated with ready-to-eat foods.Natural ...Meat products are classified as perishable foods and have favourable conditions for the multiplication of microorganisms such as Listeria monocytogenes,an important pathogen associated with ready-to-eat foods.Natural compounds are used for food preservation combined with encapsulation techniques to improve efficiency.This study evaluated the anti-Listeria potential of isolated and combined microencapsulated oregano(OEO)and cinnamon(CEO)essential oils in Italian salami.Different combination ratios of OEO and CEO were tested and 50:50 ratio(OEO:CEO)was encapsulated using sodium alginate.The microcapsules were evaluated for encapsulation efficiency(EE),morphology and action against L.monocytogenes in a meat matrix.Empty microcapsules and 50/50 combined EO were incorporated into the Italian salami to evaluate the physicochemical,microbiological and sensory properties.All combinations of EO showed L.monocytogenes inhibition zone and CIM with 1:16 dilution.The microencapsulated EO had 98.36%encapsulation efficiency.Using 2%microcapsule had a significant reduction of L.monocytogenes from the control.Even though the panellists mentioned the sandy attribute in the CATA,the salami with EO microcapsules texture did not differ from the control.Although the essential oils had high encapsulation efficiency,the smell and flavour of cinnamon and oregano interfered negatively with the sensory analysis.However,the encapsulation of the combined essential oils(50/50)significantly reduced L.monocytogenes in Italian salami.展开更多
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 diff...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.展开更多
文摘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
基金supported by the National Key R&D Program of China(Nos.2020YFD0901204,2017YFC1600706)the Natural Science Foundation of Shanghai(No.22ZR 1478500)。
文摘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.
文摘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.
基金Supported by Islamic Arad University,Shahrekord Branch,Iran(Grant No.3524)
文摘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.
文摘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.
文摘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.
文摘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.
文摘Thermal processing causes significant flavor degradation in spice-rich food products like RTE chicken.Therefore,understanding strategies to preserve volatile compounds is crucial.In this study,hydroxypropyl-betacyclodextrin(HP-β-CD)was used as a wall material to encapsulate and preserve the selected(clove,cardamom,cinnamon,and black pepper)essential oil blend(1:1:1:1 ratio)in RTE chicken cubes during retort processing for improved flavor retention.For this purpose,the inclusion complex(SME-HP-β-CD)was initially evaluated for its encapsulation efficiency(EE%),crystallinity,morphology,and thermal properties,and was also subjected to simulated saliva to study the release kinetics of flavor compounds from the HP-β-CD encapsulated matrix.It was found that the EE%was 64.35%,with a reduced crystallinity of 38.63%in SME-HP-β-CD compared to pure HP-β-CD,indicating successful encapsulation.No apparent signs of degradation were observed up to 200◦C,suggesting that the encapsulated system is thermally stable.In the case of the simulated salivary study,the Peppas-Sahlin model provided an excellent fit(R^(2)=0.99)for all the target volatiles(1,8-cineole,linalool,cinnamaldehyde,and linalool),confirming a diffusion-controlled release mechanism(n=0.25).The thermally stable SME-HP-β-CD was incorporated into RTE chicken cubes,subjected to retort processing(F_(0)=4.0 min),and analyzed for flavor composition.Headspace GC-MS revealed up to 13.64%reduction in hexanal in SME-HP-β-CD incorporated chicken cubes(CCU-SME-AP).PCA biplots of E-nose data confirmed distinct clustering from the control.Therefore,HP-β-CD encapsulation effectively preserves flavor and oxidative stability in retort-processed RTE chicken cubes.
基金supported by the Prince of Songkla University(PSU)the National Research Council of Thailand(NRCT)Research Chair Grant(N42A670596).
文摘Effects of modified atmosphere packaging(MAP)combined with epigallocatechin gallate(EGCG)on quality changes of ready-to-eat harpiosquillid mantis shrimp meat(RTE-MSM)during refrigerated storage at 4℃for 24 days were investigated.Samples were treated with EGCG at 0,200,and 400 ppm before being packaged in air or under MAP1(60%CO_(2)/10%O_(2)/30%Ar),or MAP2(80%CO_(2)/10%O_(2)/10%Ar).The control(packaged in air without EGCG)showed rapid microbial growth,with total viable counts exceeding acceptable limits of 5 log CFU/g on day 9.MAP significantly inhibited microbial proliferation(P<0.05),in which MAP2 exhibited higher efficacy than MAP1.The inhibitory effect was enhanced by EGCG in a concentration-dependent manner.Chemical spoilage indicators,including pH,total volatile basic nitrogen,trimethylamine nitrogen contents,peroxide value,and TBARS,increased during storage but were markedly reduced by MAP in combination with EGCG,especially at 400 ppm.Protein degradation,exudate loss,and texture softening were significantly retarded in MAP+EGCG treated sample.Additionally,MAP combined with EGCG preserved polyunsaturated fatty acids(EPA and DHA),retarded texture softening,and impeded the formation of spoilage-related volatile compounds.Principal component analysis(PCA)biplots,correlation heatmap and hierarchical clustering ana-lyses also confirmed the relation between the microbial growth,chemical quality indices,volatile compounds and fatty acid changes.Overall,MAP2 combined with 400 ppm EGCG was the most effective treatment,main-taining quality and extending the refrigerated shelf life of RTE-MSM to 21 days,demonstrating the potential of this multi-hurdle strategy for preserving ready-to-eat crustacean products.
基金financially supported by the Guangdong Provincial Special Fund For Modern Agriculture Industry Technology Innovation Teams(2023KJ151)the Youth Talent Support Programme of Guangdong Provincial Association for Science and Technology(SKXRC202210)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund,CAFS(2020TD69)the Key Laboratory of Aquatic Product Processing,Ministry of Agriculture and Rural Affairs,China(NYJG201309).
文摘Ready-to-eat jellyfish production is restricted by the high aluminum residue and unable use of thermal sterilization.In this study,the combined dealumination and sterilization by slightly acidic electrolyzed water(SAEW)were used to produce ready-to-eat jellyfish.The optimal aluminum removal amount reaching 120.17 mg/kg was obtained after response surface analysis.Structure observation through optical microscope after Masson staining and scanning electron microscope showed that the microstructure of jellyfish was not destroyed after SAEW treatment.The increase of total plate count(TPC)and pH value during storage was significantly inhibited by SAEW,while the other properties did not changed significantly.Staphylococcus,especially Staphylococcus epidermidis was dominant in the ready-to-eat jellyfish and many spoilage bacteria were inhibited by SAEW.The correlation network maps showed that Pseudomonas and Shewanella contributed most to the increase of TPC and pH value in the control group,while the correlated microbial genera mainly changed to Acinetobacter,Cutibacterium,and Pseudomonas after SAEW treatment,resulting in the decrease of hardness and chewiness of ready-to-eat jellyfish during storage.The inhibited Pseudomonas contributed most to the decrease of TPC and pH value after SAEW treatment.This study provides a novel technology of dealumination and sterilization for ready-to-eat jellyfish.
文摘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.
基金supported by Major Scientific and Technological Innovation Project in Shandong Province(No.2022CXGC020414)Major Scientific and Technological Innovation Project of Qingdao West Coast New Area(No.ZDKC-2022-01)+1 种基金National Natural Science Foundation of China(No.31772046)Hainan province R&D projects(No.ZDYF2024XDNY190)and Taishan Scholar Foundation of Shandong Province(No.tsqn202103033).
文摘The protective effects of molecular crosslinked ready-to-eat sea cucumber(RSC)against immunosuppression induced by cyclophosphamide in mice were investigated.After gavage of molecular crosslinked RSC,the SIgA levels of intestinal mucosa in mice were significantly increased by 31.6%(P<0.01),and the terminal differentiation of IgA+B cell was promoted with the significant up-regulation of IL-6 and IL-10 levels.Moreover,the secretion mechanism of plasma cell was mainly promoted through XBP-1s pathway mediated by IRE1(P<0.01),rather than ATF-4 and ATF-6 pathway(P>0.05).In addition,the diversity of intestinal flora was increased,and the imbalance of intestinal flora was improved.The Lachnospiraceae_NK4A136_group dominated in crosslinked group could promote the repair of intestinal mucosa.Therefore,molecular crosslinked RSC can alleviate the intestinal mucosal damage via promoting SIgA secretion and regulating gut microbiota of mice.
基金Supported by The Health System Research Project of Ningxia Hui Autonomous Region of China,No.2022-NWKY-061.
文摘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.
文摘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.
文摘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.
文摘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.
文摘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.
基金funded by the Ministry of Science and Innovation of the Spanish Government through the Research Projects ASEQURA(PID-2019-108420RB-C31)and ASEQURA2(PID2023-152192OB-C22)the Predoctoral Research Training Contract(PRE2020-092741)Funding for the open access charge was provided by Universidad de Cordoba/CBUA.
文摘Listeria monocytogenes is a resilient foodborne pathogen that forms biofilms,allowing it to persist and thrive in food-processing environments.This study examined the structural characteristics of biofilms formed by three L.monocytogenes strains,their transfer to cold-smoked rainbow trout fillets,and the bioprotective effects of two lactic acid bacteria(LAB)cocktails during storage.Confocal microscopy revealed that mixed-strain biofilms exhibited more homogeneous structures than single-strain biofilms,emphasizing their relevance in contamina-tion events.Transfer experiments demonstrated that 87.52%of L.monocytogenes biofilm cells were transferred from stainless steel to cold-smoked rainbow trout fillets after 90 s of contact,highlighting a significant contamination risk.The commercial LAB cocktail containing Lactococcus lactis subsp.lactis and Leuconostoc carnosum effectively inhibited L.monocytogenes growth under both static(5◦C)and dynamic(4-20◦C)conditions,reducing bacterial concentrations by>0.70 and>1.24 log CFU/g respectively,after 21 days.The inhibitory effect was likely driven by bacteriocin production,particularly leucocin,potentially enhanced by diacetyl production.LAB-based bioprotection effectively controlled L.monocytogenes without producing significant changes in pH or water activity.These findings highlight the need for multi-strain biofilm models to better understand contamination dynamics and support LAB-based bioprotection as a natural,effective strategy for improving food safety in smoked fish products.
基金the FAPERGS(process#19/2551-0001886-0)for partly funding the studyfinanced in part by the Coordenaç˜ao de Aperfeiçoamento de Pessoal de Nível Superior-Brazil(CAPES)-Finance Code 001.
文摘Meat products are classified as perishable foods and have favourable conditions for the multiplication of microorganisms such as Listeria monocytogenes,an important pathogen associated with ready-to-eat foods.Natural compounds are used for food preservation combined with encapsulation techniques to improve efficiency.This study evaluated the anti-Listeria potential of isolated and combined microencapsulated oregano(OEO)and cinnamon(CEO)essential oils in Italian salami.Different combination ratios of OEO and CEO were tested and 50:50 ratio(OEO:CEO)was encapsulated using sodium alginate.The microcapsules were evaluated for encapsulation efficiency(EE),morphology and action against L.monocytogenes in a meat matrix.Empty microcapsules and 50/50 combined EO were incorporated into the Italian salami to evaluate the physicochemical,microbiological and sensory properties.All combinations of EO showed L.monocytogenes inhibition zone and CIM with 1:16 dilution.The microencapsulated EO had 98.36%encapsulation efficiency.Using 2%microcapsule had a significant reduction of L.monocytogenes from the control.Even though the panellists mentioned the sandy attribute in the CATA,the salami with EO microcapsules texture did not differ from the control.Although the essential oils had high encapsulation efficiency,the smell and flavour of cinnamon and oregano interfered negatively with the sensory analysis.However,the encapsulation of the combined essential oils(50/50)significantly reduced L.monocytogenes in Italian salami.
基金supported by the national funds through FCT:Foundation for Science and Technology,Portugal,I.P.,under the project UID/AGR/04129/2020(LEAF).
文摘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.
