This paper reviews the quality changes that occur towards the food products during the frozen storage period.This research aims to determine the significant physical and chemical changes that had occurred onto the fro...This paper reviews the quality changes that occur towards the food products during the frozen storage period.This research aims to determine the significant physical and chemical changes that had occurred onto the frozen foods.Indeed,refrigerated storage is the easiest way to preserve food within short handling time.Based on the observation,it was discovered that the kinetics reactions help to establish computer-aided quality,prediction models.In certain food products,the negative impact of temperature indicated the need for a thorough evaluation of the quality parameters of individual’s kinetics reaction.In general,a reasonable temperature to store food is-18°C for most frozen foods,and this will retain the quality of commercial storage.展开更多
This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic ...This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic counts of mesophilic bacteria,yeast and mold and to detect some common foodborne pathogens according to standard microbiological criteria.Higher microbial loads in all animal-based food types,other than chicken strips were found.In contrast,plant-based items were relatively safe except paratha,dal-puri,rooti chapati,and aloo-puri.Several common pathogenic bacterial species were screened by analyzing their morphological,cultural,and biochemical characteristics.Escherichia coli was prevalent in most samples,while Salmonella species were least reported.A considerable number of samples exhibited enough microbial loads at infection or intoxication levels.展开更多
Coronavirus disease 2019(COVID-19)pandemic has spread in 220 countries/regions towreak havoc to human beings around theworld.At present,the second wave of COVID-19 has begun in many European countries.The complete con...Coronavirus disease 2019(COVID-19)pandemic has spread in 220 countries/regions towreak havoc to human beings around theworld.At present,the second wave of COVID-19 has begun in many European countries.The complete control of COVID-19 is very urgent.Although China quickly brought the virus under control,there have been eight sporadic outbreaks in China since then.Both in Xinfadi of Beijing and Dalian outbreak of COVID-19,environmental swab samples related to imported cold chain food were tested nucleic acid positive for SARS-CoV-2.In this outbreak in Qingdao,we directly isolated SARS-CoV-2 from the cod outer package's surface swab samples.This is the first time worldwide,SARS-CoV-2 were isolated from the imported frozen cod outer package's surface,which showed that imported frozen food industry could import SARS-CoV-2 virus.展开更多
Improving gastrointestinal flora with probiotics is a promising method of treating and preventing many diseases.However,in food industry,introduction of probiotics is limited by the shelf life of products,as well as b...Improving gastrointestinal flora with probiotics is a promising method of treating and preventing many diseases.However,in food industry,introduction of probiotics is limited by the shelf life of products,as well as by the reduction of bacterial viability during storage.Thus,introduction of probiotics into foods to be frozen is a promising method to extend the shelf life of probiotic products.However,the storage of living cells in frozen products involves their damage during freezing and subsequent storage at temperatures below 0℃.Therefore,some technological solutions are required to protect probiotics during storage at sub-zero.Today,encapsulation,addition of cryoprotectants and prebiotics,as well as adaptation of microorganisms are widely used techniques of protecting probiotics.The combination of various protection methods is a promising way to improve the viability of probiotics during storage.Studies aimed at investigating various combinations of hurdle methods and their effect on bacterial survival are of great interest.This review compiles the most common methods of preserving probiotics in frozen foods,describing their effects,variety of approaches,and effectiveness.The main mechanisms of bacterial cell damage by freezing are described.Further trends in probiotic protection in frozen foods are also discussed.展开更多
Experiments were conducted to evaluate the efficacy of two frozen organism (with and without instant Nannochloropsis oculata and with and without instant encapsulated Spirulina) and artificial diet (with and without a...Experiments were conducted to evaluate the efficacy of two frozen organism (with and without instant Nannochloropsis oculata and with and without instant encapsulated Spirulina) and artificial diet (with and without artificial encapsulated shrimp larvae feed) with live food as continues feed in the larval rearing of blue swimming crab, Portunus pelagicus. The larvae were conducted with six treatments and each treatment with three replications on newly one day hatched larvae in each replication. Results showed that these larvae fed with a combination diet of instant frozen N. oculata, Artemia nauplii and rotifer give a higher survival rate till 1st day juvenile crab compared to the treatment with instant encapsulated Spirulina and artificial diet (with artificial encapsulated shrimp larvae feed). One of experiments treated with encapsulated Spirulina recorded only 16 days for the zoea to reach the C1, one day earlier as compared to previous trials treated with and without instant frozen N. oculata. One of the experiments treated with artificial encapsulated shrimp larvae feed recorded 18 days for the zoea to reach the C1, 1 to 2 days longer as compared to all the previous trials earlier. Food type influenced survival, development, and metamorphosis to megalopa and 1st day juvenile crab of P. pelagicus zoea larvae. Our findings illustrate that the best survival, the most rapid development and the highest number of 1st day juvenile crabs were obtained from larvae fed with a combination diet of frozen N. oculata, Artemia nauplii and rotifer from hatching till the 1st day juvenile crab.展开更多
Objective:To determine the proportion of imported frozen fish contaminated with Salmonella among retail food stores and supermarkets in the Eastern Province of Saudi Arabia.Methods:A total of 223 frozen freshwater fis...Objective:To determine the proportion of imported frozen fish contaminated with Salmonella among retail food stores and supermarkets in the Eastern Province of Saudi Arabia.Methods:A total of 223 frozen freshwater fish purchased from different supermarkets and grocery stores were analyzed for the presence of foodborne pathogen Salmonella.The isolation of Salmonella was determined and confirmed by using the methods of US Food and Drug Administration's Bacteriological Analytical Manual.CHROMagar Salmonella plus,biochemical tests and API 20E strips.Antimicrobial susceptibilities of Salmonella isolates were determined by the disk diffusion method on Muller-Hinton agar,as described by Kirby-Bauer.in accordance with the guidelines of the Clinical and Laboratory Standards Institute.Results:Out of the total 223 fish samples(20 of catfish,18 of carfu,20 of mirgal,25 of milkfish,35 of mackerel,75 of tilapia,and 30 of rohu),89(39.9%)were tested positive for Salmonella.The prevalence of positive samples were reported for the freshwater fish of pangas(60.0%,n=12),carfu(27.7%,n=5),mirgal(35.0%,n=7),milkfish(52.0%,n=13),mackerel(31.4%,n=11),tilapia imported from Thailand(64.0%,n=16),tilapia imported from India(28.0%,n=14),rohu imported from Thailand(26.6%,n=4)and rohu imported from Myanmar(46.6%,n=7).A total of 140 isolates of Salmonella spp.were yielded from at least seven different types of frozen freshwater fish imported from 5 different countries and were tested for their susceptibility to 16 selected antimicrobial agents.The highest antibiotic resistance was observed to tetracycline(90.71%)followed by ampicillin(70%)and amoxicillin-clavulanic acid(45%).Conclusions:The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp.And the study recommend and suggest that there is a need for adequate consumer measures.展开更多
本研究利用多准则决策分析对经不同复热方式(微波、煎制、空气炸制、烤制)的预制植物基蛋饼的质构属性、持水力以及凝胶特性等宏观品质指标进行了全面评估。实验结果显示,空气炸制在质构维持、色泽保留以及感官质量等多方面拥有综合优势...本研究利用多准则决策分析对经不同复热方式(微波、煎制、空气炸制、烤制)的预制植物基蛋饼的质构属性、持水力以及凝胶特性等宏观品质指标进行了全面评估。实验结果显示,空气炸制在质构维持、色泽保留以及感官质量等多方面拥有综合优势,具有最高的理想系数(Coefficient of Desirability,C值),成为预制植物蛋饼最为适配的复热途径。而微波复热具有最低的C值,因为其在复热过程中大量失水使淀粉结晶与网络结构瓦解,破坏食品整体结构完整性,导致感官质量劣变。同时,煎制因高温油脂的介入引起了蛋白质二级结构无序化,使其网络强度进一步降低,继而对成品品质产生负面影响。此外,在−20℃冻藏条件下对预制植物基蛋饼的品质劣变程度进行监测,发现60 d的贮藏周期是确保预制蛋饼品质稳定性的最长时限。因为植物蛋饼在冻藏90 d后其凝胶强度和冻融脱水率出现了显著的攀升(P<0.05)。本研究通过深入探究预制植物蛋饼在复热与贮藏环节中的关键特性变化规律,为预制植物蛋饼在食品加工领域的工业化应用以及市场推广提供针对性的理论依据与实践指导。展开更多
为确定抹茶手抓饼的最佳配方,研究了抹茶对手抓饼面团质构和色差的影响。通过单因素试验,初步确定了抹茶粉、混合油和食盐的添加量;通过响应面优化和验证试验,确定了抹茶手抓饼的配方为面粉500 g (低筋面粉250 g+高筋面粉250 g),抹茶粉2...为确定抹茶手抓饼的最佳配方,研究了抹茶对手抓饼面团质构和色差的影响。通过单因素试验,初步确定了抹茶粉、混合油和食盐的添加量;通过响应面优化和验证试验,确定了抹茶手抓饼的配方为面粉500 g (低筋面粉250 g+高筋面粉250 g),抹茶粉2.1%,混合油4.4%,食盐1.8%,白砂糖8 g,味精3 g,水300 m L,在此配方条件下制作的抹茶手抓饼外层酥脆,内层香软,色泽翠绿鲜亮,茶香明显,无油腻感,回味清爽。展开更多
文摘This paper reviews the quality changes that occur towards the food products during the frozen storage period.This research aims to determine the significant physical and chemical changes that had occurred onto the frozen foods.Indeed,refrigerated storage is the easiest way to preserve food within short handling time.Based on the observation,it was discovered that the kinetics reactions help to establish computer-aided quality,prediction models.In certain food products,the negative impact of temperature indicated the need for a thorough evaluation of the quality parameters of individual’s kinetics reaction.In general,a reasonable temperature to store food is-18°C for most frozen foods,and this will retain the quality of commercial storage.
文摘This study aimed to assess the microbiological quality of 159 animal-and plant-based ready-to-cook(RTC)frozen food items currently popular in Dhaka.Microbiological analyses were carried out to enumerate total aerobic counts of mesophilic bacteria,yeast and mold and to detect some common foodborne pathogens according to standard microbiological criteria.Higher microbial loads in all animal-based food types,other than chicken strips were found.In contrast,plant-based items were relatively safe except paratha,dal-puri,rooti chapati,and aloo-puri.Several common pathogenic bacterial species were screened by analyzing their morphological,cultural,and biochemical characteristics.Escherichia coli was prevalent in most samples,while Salmonella species were least reported.A considerable number of samples exhibited enough microbial loads at infection or intoxication levels.
基金supported by the National Key Research and Develop-ment Project(2020YFC0846200,2020YFC0840800).
文摘Coronavirus disease 2019(COVID-19)pandemic has spread in 220 countries/regions towreak havoc to human beings around theworld.At present,the second wave of COVID-19 has begun in many European countries.The complete control of COVID-19 is very urgent.Although China quickly brought the virus under control,there have been eight sporadic outbreaks in China since then.Both in Xinfadi of Beijing and Dalian outbreak of COVID-19,environmental swab samples related to imported cold chain food were tested nucleic acid positive for SARS-CoV-2.In this outbreak in Qingdao,we directly isolated SARS-CoV-2 from the cod outer package's surface swab samples.This is the first time worldwide,SARS-CoV-2 were isolated from the imported frozen cod outer package's surface,which showed that imported frozen food industry could import SARS-CoV-2 virus.
基金supported by the Russian Science Foundation(grant No.21-16-00124,https://rscf.ru/en/project/21-16-00124/).
文摘Improving gastrointestinal flora with probiotics is a promising method of treating and preventing many diseases.However,in food industry,introduction of probiotics is limited by the shelf life of products,as well as by the reduction of bacterial viability during storage.Thus,introduction of probiotics into foods to be frozen is a promising method to extend the shelf life of probiotic products.However,the storage of living cells in frozen products involves their damage during freezing and subsequent storage at temperatures below 0℃.Therefore,some technological solutions are required to protect probiotics during storage at sub-zero.Today,encapsulation,addition of cryoprotectants and prebiotics,as well as adaptation of microorganisms are widely used techniques of protecting probiotics.The combination of various protection methods is a promising way to improve the viability of probiotics during storage.Studies aimed at investigating various combinations of hurdle methods and their effect on bacterial survival are of great interest.This review compiles the most common methods of preserving probiotics in frozen foods,describing their effects,variety of approaches,and effectiveness.The main mechanisms of bacterial cell damage by freezing are described.Further trends in probiotic protection in frozen foods are also discussed.
文摘Experiments were conducted to evaluate the efficacy of two frozen organism (with and without instant Nannochloropsis oculata and with and without instant encapsulated Spirulina) and artificial diet (with and without artificial encapsulated shrimp larvae feed) with live food as continues feed in the larval rearing of blue swimming crab, Portunus pelagicus. The larvae were conducted with six treatments and each treatment with three replications on newly one day hatched larvae in each replication. Results showed that these larvae fed with a combination diet of instant frozen N. oculata, Artemia nauplii and rotifer give a higher survival rate till 1st day juvenile crab compared to the treatment with instant encapsulated Spirulina and artificial diet (with artificial encapsulated shrimp larvae feed). One of experiments treated with encapsulated Spirulina recorded only 16 days for the zoea to reach the C1, one day earlier as compared to previous trials treated with and without instant frozen N. oculata. One of the experiments treated with artificial encapsulated shrimp larvae feed recorded 18 days for the zoea to reach the C1, 1 to 2 days longer as compared to all the previous trials earlier. Food type influenced survival, development, and metamorphosis to megalopa and 1st day juvenile crab of P. pelagicus zoea larvae. Our findings illustrate that the best survival, the most rapid development and the highest number of 1st day juvenile crabs were obtained from larvae fed with a combination diet of frozen N. oculata, Artemia nauplii and rotifer from hatching till the 1st day juvenile crab.
基金Supported by the Deanship of Scientific Research,University of Dammam (Grant No.2012139)
文摘Objective:To determine the proportion of imported frozen fish contaminated with Salmonella among retail food stores and supermarkets in the Eastern Province of Saudi Arabia.Methods:A total of 223 frozen freshwater fish purchased from different supermarkets and grocery stores were analyzed for the presence of foodborne pathogen Salmonella.The isolation of Salmonella was determined and confirmed by using the methods of US Food and Drug Administration's Bacteriological Analytical Manual.CHROMagar Salmonella plus,biochemical tests and API 20E strips.Antimicrobial susceptibilities of Salmonella isolates were determined by the disk diffusion method on Muller-Hinton agar,as described by Kirby-Bauer.in accordance with the guidelines of the Clinical and Laboratory Standards Institute.Results:Out of the total 223 fish samples(20 of catfish,18 of carfu,20 of mirgal,25 of milkfish,35 of mackerel,75 of tilapia,and 30 of rohu),89(39.9%)were tested positive for Salmonella.The prevalence of positive samples were reported for the freshwater fish of pangas(60.0%,n=12),carfu(27.7%,n=5),mirgal(35.0%,n=7),milkfish(52.0%,n=13),mackerel(31.4%,n=11),tilapia imported from Thailand(64.0%,n=16),tilapia imported from India(28.0%,n=14),rohu imported from Thailand(26.6%,n=4)and rohu imported from Myanmar(46.6%,n=7).A total of 140 isolates of Salmonella spp.were yielded from at least seven different types of frozen freshwater fish imported from 5 different countries and were tested for their susceptibility to 16 selected antimicrobial agents.The highest antibiotic resistance was observed to tetracycline(90.71%)followed by ampicillin(70%)and amoxicillin-clavulanic acid(45%).Conclusions:The obtained results of this study shows that these raw retail imported frozen freshwater fish are contaminated with potentially pathogenic Salmonella spp.And the study recommend and suggest that there is a need for adequate consumer measures.
文摘本研究利用多准则决策分析对经不同复热方式(微波、煎制、空气炸制、烤制)的预制植物基蛋饼的质构属性、持水力以及凝胶特性等宏观品质指标进行了全面评估。实验结果显示,空气炸制在质构维持、色泽保留以及感官质量等多方面拥有综合优势,具有最高的理想系数(Coefficient of Desirability,C值),成为预制植物蛋饼最为适配的复热途径。而微波复热具有最低的C值,因为其在复热过程中大量失水使淀粉结晶与网络结构瓦解,破坏食品整体结构完整性,导致感官质量劣变。同时,煎制因高温油脂的介入引起了蛋白质二级结构无序化,使其网络强度进一步降低,继而对成品品质产生负面影响。此外,在−20℃冻藏条件下对预制植物基蛋饼的品质劣变程度进行监测,发现60 d的贮藏周期是确保预制蛋饼品质稳定性的最长时限。因为植物蛋饼在冻藏90 d后其凝胶强度和冻融脱水率出现了显著的攀升(P<0.05)。本研究通过深入探究预制植物蛋饼在复热与贮藏环节中的关键特性变化规律,为预制植物蛋饼在食品加工领域的工业化应用以及市场推广提供针对性的理论依据与实践指导。
文摘为确定抹茶手抓饼的最佳配方,研究了抹茶对手抓饼面团质构和色差的影响。通过单因素试验,初步确定了抹茶粉、混合油和食盐的添加量;通过响应面优化和验证试验,确定了抹茶手抓饼的配方为面粉500 g (低筋面粉250 g+高筋面粉250 g),抹茶粉2.1%,混合油4.4%,食盐1.8%,白砂糖8 g,味精3 g,水300 m L,在此配方条件下制作的抹茶手抓饼外层酥脆,内层香软,色泽翠绿鲜亮,茶香明显,无油腻感,回味清爽。
