Study Of The Quality Of Chilled Chicken During Storage Based On Metagenomics And Metabolomics Approach

In this paper,the microbial community diversity,abundance and community during differernt storage days were studied under 4?and 37?enrichment temperature,respectively,by using the method of metagenomics and traditional physiological and biochemical indexes,detecting the community structure and its variation with the change of storage days,so as to determine the dominant spoilage bacteria in the chilled chicken.Secondly,the metabolites of chilled chicken were analyzed by LC-MS metabolomics method.The aim of this was to find out the different metabolites and the main metabolic pathways,and to analyze the relationship between the d ynamic changes and meat quality,which provide scientific and theoretical basis for the development of chilled chicken quality control and efficient preservation technology development.The results are as follows:(1)The sensory score,the number of psychrophilic bacteria,the total number of colonies,the p H and the TVB-N were increased with the increase of storage days at 4?enrichment temperature.The results showed that the sensory score decreased gradually with the increase of storage days,and began to be corrupt after 6 days.The total number of colonies,psychrophilic bacteria and the TVB-N value increased gradually.The total number of colonies exceeded 10~6 cfu/g on the 8th day and the TVB-N value reached 25mg/100g after the 8th day.p H value in 0?6d showed a trend of fluctuation and decline,until after 6d gradually increased.Based on the above indicators that chilled chicken storage shelf was 6 days approximately,after 8 days the corruption has occurred,which can not edible.(2)5 phylum,12 class,20 order,39 family,53 genus were detected in chilled chicken during storage process.In the phylum level,Proteobacteria,Firmicutes and Bacteroidetes were dominant bacterias.In genus level,Pseudomonas,Shewanellaceae and Acinetobacter were the main dominant bacteria in the early s tage of storage(0?4 days)at the 4?enrichment temperature,and Pseudomonas accounting for the highest proportion,up to 44.03%;In the middle and later periods of the storage,Myroides increased rapidly and greater than the Pseudomonas,which became the dominant spoilage bacteria.At 37?enrichment temperature,C itrobacter,Proteus,Lactococcus and Bacteriap-other predominate in the early stage of storage.In the middle and later periods of the storage,Myroides and Wohlfahrtiimonas were dominant spoilage bacteria.(3)The metabolites of chilled chicken during storage were analyzed by LC-MS metabolomics method integrally.The results showed that there were significant difference between the 0 days and the other four days groups.63 significant difference metabolites were obtained by screening for VIP>2 and p<0.05.These differences metabolites mainly aggregated in the amino acids,amines,nucleosides and nucleotides,carbohydrates,organic acids and other substances,and with the increase in storage days have shown a certain increase and down.The main metabolic pathways involved are purine metabolism,amino acid biosynthesis,nicotinate and nicotinamide metabolism,tryptophan metabolism,tyrosine metabolism,histidine metabolism,indicating that the quality of chilled chicken storage is closely related to these metabolic pathways.