Correlation Analysis Between Metabolic Enzymes And Flavor Substances Formation In Chilled Fresh Tan Sheep Meat During Storage

The structure and functional characteristics of protein in Tan sheep meat muscle after slaughter have a significant impact on the quality of meat and meat products.During the ripening period,a series of biochemical changes occur in Tan sheep meat after slaughter,which changes the structure and composition of muscle protein,thus affecting meat quality.In this paper,the protein types and abundance of Tan sheep meat stored after slaughter were analyzed by proteomics technology at 0-4?for 0,4,8 and 12 days,with emphasis on enzymatic proteins.Using Omics Bean data integration and analysis cloud platform,the linkage between metabolic enzymes and metabolic changes was studied by proteomics and metabolomics association,the differential metabolic enzymes involved in metabolic pathways and their corresponding relationship with differential metabolites were determined,and the biochemical reaction driving mechanism of differential metabolic enzymes on metabolic pathway conversion was studied.The main results are as follows:1.Using isobaric tags for relative and absolute quantitation and liquid chromatography tandem mass spectrometry(LC-MS/MS),the differentially expressed proteins of chilled fresh Tan sheep meat(divided into 0 d/4 d group,4 d/8 d group and 8 d/12 d group)were detected.The results showed that 1066 trusted proteins were screened out in group one,1106 trusted proteins in group two and 1084 trusted proteins in group three.814 credible proteins were identified in all three groups.Based on the screened credible proteins,159 differentially significant proteins were screened out in group one,151 differentially significant proteins in group two and 154 differentially significant proteins in group three.Hierarchical clustering analysis and screening were carried out on the selected differential proteins,and 34 different proteins with great changes in the content of Tan sheep meat after slaughter were found.2.Taking differentially expressed proteins as the research object(focusing on enzymatic proteins).Based on proteomics technology,the screened differentially expressed proteins were quantitatively and qualitatively analyzed to determine the biological processes,cell components,molecular functions and metabolic pathways of differentially expressed proteins.The differentially expressed proteins were identified by the analysis of differentially expressed proteins obtained by the members of this research group.The effect of quality on metabolites.The results showed that the biological processes involved in differential proteins included ATP metabolism,ribonucleoside triphosphate metabolism,myofibril,contractile fibers,mitochondrial protein complexes,and hydrolase and redox enzyme activities.These 34 differential proteins participate in metabolic pathways,including glycolysis/gluconeogenesis,oxidative phosphorylation,amino acid biosynthesis,pyruvate metabolism,fatty acid biosynthesis and so on.Among them,12 metabolic enzymes such as glycogen phosphorylase,propione phosphate isomerase and pyruvate kinase are the key enzymes in each metabolic pathway,which open,convert and close the metabolic pathway of flavor precursors.It has an important influence.3.Taking metabolic enzymes as the research object,the correlation between metabolic enzymes and precursors and intermediates of flavor substances was found on the basis of previous experimental results.The results showed that the types of differentially expressed proteins and metabolites decreased with the prolongation of storage time.At 0d/4d,the significant metabolic pathways were carbon metabolism,glycolysis/gluconeogenesis,oxidative phosphorylation,pyruvate metabolism,in which glycogen phosphorylase and propionate phosphate isomerase were up-regulated;at 4d/8d,the significant metabolic pathways were fatty acid biosynthesis and amino acid biosynthesis,in which glycogen phosphorylase and propionate phosphate isomerase were down-regulated,and 3-phosphate glycerol dehydrogenase was down-regulated.The expression of fatty acid synthase,trans-2-decenyl-[acyl-carrier protein]isomerase and medium chain acyl-[acyl-carrier-protein]hydrolase were down-regulated at 8d/12d.Because of the change of the expression of metabolic enzymes,the original metabolic pathway changed and a new metabolic pathway was produced in 0-12 days.Under the control of key metabolic enzymes,different biochemical metabolism occurs in different periods of time.Each metabolic enzyme cooperates with each other,opening and transforming metabolic pathways,which changes the metabolites in the body after slaughter and produces flavor precursors.In this paper,the process of flavor precursor formation and its regulation mechanism during postmortem storage of Tan sheep meat were discussed at the molecular level,and the metabolic dynamic evolution and biochemical reaction mechanism of pathway transformation were revealed.It provided theoretical reference for improving meat quality and flavor control technology of chilled fresh Tan sheep meat,and laid a foundation for the construction of biological theory of chilled fresh meat preservation system.