Effect of Cooking Methods on the Chemical Compounds Associated with Umami Taste in Duck Breast Meat

Dry-curing,wet-curing,stewing and marinating are sequential Chinese traditional meat-processing methods dating back thousands of years ago.However,little information is available about the contribution of each processing stage to the umami taste in duck breast meat.Therefore,effects of those meat-processing methods on umami taste related chemical compounds were determined in this study.Dry-curing significantly increased free amino acids,oligopeptides and nucleotides and nucleotides degradation products(P<0.05),however,in the following wet-curing,stewing and marinating stages,the percentages of inosine and hypoxanthine were gradually declined.Electronic tongue and principle component analysis results revealed the difference between dry-cured/wet-cured duck breast meat and marinated/stewed duck breast meat was due to the increase of free amino acids,oligopeptides and inosine monophosphate.Therefore,dry-curing is an important stage in meat processing,not only it produces a pool of taste related compounds,it also stimulates the enzyme activities in the muscle.Meanwhile,in the stewing stage,the umami taste profile of duck breast meat was gradually established.We can conclude that dry-curing and stewing are the two crucial stages to form the umami taste profile in duck breast meat.

Critical review of radio-frequency(RF)heating applications in food processing

Conventional thermal treatment in food processing relies on the transfer of heat by conduction and convection.One alternative to this conventional thermal treatment is radio-frequency(RF)heating in which electromagnetic energy is transferred directly to the heated product.The longer wavelengths of RF compared with microwaves are able to penetrate further into the food products resulting in more even heating.A review of RF heating for the food processing industry is presented here with an emphasis on scientific principles and the advantages and applications of RF.Applications of RF heating include blanching,thawing,drying,and processing of foods.RF heating represents considerable potential for additional research and the transfer of technology to the food processing industry.Computer simulation can be used to improve RF heating uniformity.Moreover,the heating uniformity in the rotated eggs is greater than in the static eggs.RF has also been used to blanch vegetables to increase ascorbic acid content to achieve the highest vitamin C levels.The use of the thawing technology has resulted in better quality of treated food.There has been increased interest in the RF-drying method due to the homogeneity of heating,greater penetration depth,and more stable control of the product temperature.RF-treated meat had improved quality and coagulation with acceptable taste and appearance.In addition,RF heating is used in pasteurization of yogurt and destruction of microorganisms in liquid and solid foods.

Recent developments of lactic acid bacteria and their metabolites on foodborne pathogens and spoilage bacteria:Facts and gaps

Lactic acid bacteria(LAB)are common microorganisms found in various ecosystems including in plants,fermented foods,and the human body.Exploring the biodiversity of lactic acid microflora and characterization of LAB is a new approach to form a variety of starter communities to create innovative nutritional food matrices.There has been growing interest in LAB isolated from non-dairy environments as these bacteria exhibit significant metabolic diversity and have unique taste-forming activities.Disease may be prevented,or treated by LAB but the treatment of disease conditions with LAB is highly dependent on the host's microbiome and diet and varies in both effectiveness and side effects from individual to individual.Future perspectives on the study of LAB may be related to the expansion of our knowledge in the fields of genetics and genetic engineering.The application of genetic science may help to improve existing strains and develop new strains with characteristics designed for specific purposes.Therefore,the preservative effects of LAB and their metabolites,as well as their interaction on the growth of food borne pathogens and food spoilage microorganisms were elucidated.In addition,the competitive models for microbial growth between LAB and other microorganisms as well as the role of LAB in the elimination of toxic compounds in food products were discussed.Moreover,the review provided an overview of the risks and benefits of using LAB in the food industry.