The Regulatory Mechanism Of Glycolytic Pathway On Energy Level And Quality Of Tan Lamb During Post-slaughter Ageing

After slaughter,the internal ischemia,lack of oxygen,and insufficient energy supply of Tan lamb will rapidly activate glycolysis and continue until glycolytic enzyme inactivation or substrate depletion,which is the main source of energy required for post-slaughter biochemical metabolism,therefore,glycolysis has an important regulatory effect on the energy metabolism level and meat quality change of post-slaughter Tan lamb.At present,the research on the effect of glycolysis on energy metabolism and quality of Tan lamb mainly focuses on the expression of metabolic enzymes,the change of energy substance content,and the correlation between glycolysis indexes and meat quality.There is still a lack of research on regulating the metabolic level and meat quality of mutton in the post-slaughter beach by activating the glycolytic pathway.The energy metabolism level,cooking loss,centrifugation loss,water distribution,shear force and other indicators during postslaughter ageing were measured,the influence of glycolysis pathway on the metabolic level of Tan lamb was studied,then analyze the effect on the quality of Tan lamb and its relationship with glycolysis pathway,and the core genes affecting the quality of Tan lamb in glycolysis were analyzed by transcriptomics to reveal the influence mechanism of glycolysis pathway on Tan lamb quality.The specific research content and results are as follows:1.The effect of glycolytic pathway on the metabolic level of Tan lamb during post-slaughter ageing was clarified.The expression of PFKM protein was detected by SDS-PAGE and WB to verify that the glycolysis pathway was activated by CaCl2.At the same time,the energy level during post-slaughter ageing was determined,and the effect of glycolytic pathway on the metabolic level of Tan lamb was analyzed.The results showed that the expression of PFKM protein decreased during post-slaughter ageing,indicating that the glycolytic pathway was successfully activated.The CaCl2 group increased the activity of key enzymes HK,PK,PFK and AMPK,accelerated the level of glycolysis after slaughter,promoted the decomposition of glycogen,increased the production of lactic acid,and caused a rapid decrease in pH CaCl2 treatment significantly reduced the levels of ATP,ADP and AMP,and increased the content of NADH.It is indicated that the glycolytic pathway affects the level of energy metabolism during ageing by accelerating the decrease in pH and the accumulation of mature metabolites.2.The effect of glycolysis pathway on the quality of Tan lamb during post-slaughter ageing was clarified.The study found that the water retention,MFI value and b*of the CaCl2 group were higher than those of the blank group and the control group,and the shear force and a*were lower than those of the other two groups.By accelerating the process of glycolysis,increasing the energy level during post-slaughter ageing,while inhibiting the production of oxygenated myoglobin,activating the activity of calcium-activating enzymes,changing the structure of myofibril and shortening the muscle protein molecular space,the process of myofibril small pieces and the hydrolysis rate of myofibrillar protein are accelerated,resulting in the deterioration of meat color,water loss and tenderness of Tan lamb.3.The effect of glycolysis core genes on the quality of Tan lamb during post-slaughter ageing was expounded.High-throughput sequencing technology was used to study the changes of transcriptome of hind leg meat of Tan lamb ageing at 0,4 and 8 days at 4℃.Five glycolytic genes PFKM,GADPH,PGAM2,ENO3 and PKM were identified as core genes affecting the quality of Tan lamb,which were mainly enriched in cytoamide metabolism,ATP metabolism,skeletal muscle contraction and ribosomes to participate in glycolysis,ribosomes and p53 signaling pathways,bind to ions or cytoskeletal proteins,participate in the regulation of ATPase activity and muscle contraction,cause mitochondrial ATP synthesis coupled with proton transport and hydrogen ion transmembrane transport,resulting in changes in the structure of muscle fibers of Tan lamb.This causes changes in the energy level and quality of the meat.Glycolysis of Tan lamb after slaughter affected the water adsorption of different genes,the degradation degree of structural proteins and the activity of glycolytic enzymes,thereby affecting meat quality.