Effect Of Modified Atmosphere Packaging And Grape Seed Extract On Shelf Life And Microbial Diversity Of Roast Chicken

Roast chicken is a unique ready-to-eat chicken product with special cooking methods and a long history.Due to its unique flavor and rich nutrition,it is popular around the world.China is a big country in the production and consumption of chicken.In 2018,China's chicken production was 13.55 million tons and its consumption was 11.59 million tons.Due to the continuous expansion of the market,roast chicken is increasingly favored by consumers.However,during transportation and storage,due to the nutrient-rich and high water activity of chicken meat,it provides a good environment for the growth and reproduction of microorganisms in the meat,which makes the quality of roast chicken products decline rapidly.This has seriously affected the sales range and sales time of roast chicken products,which has restricted the development of the roast chicken industry.Modified atmosphere packaging technology and natural functional material preservation technology are emerging fresh-keeping technologies in recent years,which have the advantages of simple operation,remarkable effect,low cost,etc.,but their application in the preservation of roast poultry products is less.Therefore,how to apply these two preservation technologies to roast chicken products to improve the quality of roast chicken products and prolong the shelf life of roast chicken is the main purpose of this study.This study investigated the effects of modified atmosphere packaging on the microbial quality,physical and chemical quality and sensory quality of roast chickens under low temperature storage,in order to find the optimal gas ratio,improve the quality and shelf life of roast chicken,and use 16SrDNA Qualcomm.The quantitative sequencing technology monitors the dynamic changes of bacterial communities in roast chickens in tray packaging and modified atmosphere packaging,and finds out the dominant spoilage bacteria that cause rotten chicken spoilage during low temperature storage.On this basis,the selection of a suitable natural preservative is targeted to inhibit the growth of dominant spoilage bacteria in roast chicken,thereby further improving the quality and shelf life of roast chicken.At the same time,it provides theoretical basis and practical guidance for ensuring the edible quality of roast chicken and developing fresh-keeping methods for roast chicken.1.Effect of modified atmosphere packaging on shelf-life of roast chicken meatThe objective of this study was to investigate the effect of packaging method on physicochemical and microbiological properties of roast chicken meat.The samples were stored under normal atmosphere(A)and four different proportions of CO2 and N2 modified atmosphere packaging(MAP)conditions:N(N2,100%),M2(CO2/N2,20%/80%),M3(CO2/N2,30%/70%)and M4(CO2/N2,40%/60%).Microbiological quality,pH,headspace gas composition,color and lipid oxidation of roast chicken meat were measured.The time to reach the acceptable total viable counts(TVC,4 log CFU/g)was 8,16,18,21 and 22 d in A,N,M2,M3 and M4 samples,respectively.The thiobarbituric acid(TBA)values under MAP packaging were lower than those in normal packaging.Moreover,the growth rate of TVC,molds and yeasts in roast chicken was slower with the increase of carbon dioxide content in MAP.The present findings demonstrate that packaging with CO2/N2,40%/60%could extend the longer shelf-life of roast chicken at 4?.2.Effect of different packaging methods on the diversity of roast chickenThis study systematically investigated the dynamic changes of bacterial communities in roast chicken under normal and modified atmosphere packaging.The samples were stored under normal atmosphere(A)and CO2/N2,40%/60%modified atmosphere packaging(MAP)conditions for 28 days at 4?.Changes in the number and type of microorganisms in roast chicken during storage were measured by using cultural methods and 16S rDNA sequencing techniques.Bacteroides,Chryseobacterium,Lactobacillus,and Acinetobacter were found more than other bacteria in initial roast chicken meat.In the normal packaging,Pseudomonas rapidly grew into the main spoilage bacteria of roast chicken after 7 days,and its relative abundance accounted for more than 90%of the whole flora.In modified atmosphere packaging,Halomonas was the main spoilage organism in roast chicken during the middle of storage(14d).On the 21st to 28th day of storage,Pseudomonas became the main spoilage bacteria in roast chicken,but its relative abundance was much smaller than the relative abundance of Pseudomonas in normal packaging,followed by Lachnospiraceae NK4A136 group and ltererythrobacter.Our research shows that the microbes in roast chicken were mainly from the processing environment and the operators.The combination of modified atmosphere packaging and low temperature could effectively improve the quality and safety of roast chicken meat.3.The effect of grape seed extract solution combined with modified atmosphere packaging on the quality of roasted chickenThis study investigated the effect of grape seed extract solution combined with modified atmosphere packaging on the quality of roast chicken.Firstly,different concentrations of grape seed extract solution(0.2%,0.5%,0.8%,1.0%)were used to spray the roasted chicken and then modified atmosphere packaging.The total number of colonies in the roast chicken on the 21st day was used as an indicator to select the appropriate grape seed extract solution concentration.Choose three different treatment methods:A(Normal packaging),M(Modified atmosphere packaging,CO2/N2=40%/60%)and P(0.5%grape seed extract solution combined with modified atmosphere packaging).The TVC,Pseudomonas,LAB number,pH value,headspace air content,fat oxidation degree,and sensory characteristics were analyzed every 6-7 days.Studies have shown that the grape seed extract preservation solution can effectively reduce the growth rate of total aerobic bacteria,pseudomonas,mold and yeast in roast chicken during storage,reduce the fat oxidation rate in roast chicken,and maintain the color of roast chicken and sensory properties.Compared with normal packaging and single modified atmosphere packaging,the storage method of grape seed extract solution combined with modified atmosphere packaging can effectively extend the shelf life of roast chicken.