Effect Of Intramuscular Fat On Finishing Pork Quality And Adipogenesis Regulation Of Intramuscular Lipid Droplets

The intramuscular fat content of the pig affects the tenderness,juiciness and flavor of the meat.How to improve the development of intramuscular lipid droplets that let more lipids are deposited in the muscle becomes a topic of common concern for producers and scientific researchers.In recent years,with the rapid development of a variety of histological detection technologies,lipid droplet purification technology has attracted more and more attention.Isolation and purification of lipid droplets with biological activity and high purity is the prerequisite for ensuring the reliability of biological function research.In this study,the method of ultracentrifugation and purification of intramuscular lipid droplets of longissimus dorsi muscle was established.Morphological observation and purity verification of isolated lipid droplets were provided to provide technical support for the study of intramuscular fat production and molecular regulation mechanisms.It is of great significance to study the deposition of fat in muscle,improve meat quality and the edible value of pork,and produce meat products that are beneficial to human health.The test results are as follows:1.In order to study the effect of intramuscular fat content on pig carcass traits and meat quality characteristics under different slaughter weights,90±2.0 kg and 120±2.0 kg “Duroc ×Landrace ×Yorkshire” three-way crossbred pigs were slaughtered.Its intramuscular fat,meat quality and nutrient composition analysis.The results showed that: compared with 120 kg body weight at slaughter,1)The intramuscular fat content increased significantly with the increase of body weight;2)The body weight and backfat thickness were significantly increased with slaughter weight of 120 kg body weight.,loineye aera,slaughter rate and other indicators(P <0.01).3)With the increase of slaughter weight,pork flesh color was significantly increased(P<0.01),water loss rate and cooking loss were reduced,and muscle shearing force was significantly increased(P<0.05).4)120 kg body weight significantly increased the content of unsaturated fatty acids(P<0.05)and significantly reduced the content of saturated fatty acids(P<0.05).5)With the increase of body weight 120 kg body weight significantly increased the content of essential amino acids during slaughter(P<0.05),and significantly increased the content of amino acids in the umami(P<0.01).2.In order to establish the method of Isolation and purification of intramuscular lipid droplets of longissimus dorsi muscle,this study attempted to isolate the intramuscular lipid droplets and purify them.The longissimus dorsi muscle tissue samples were subjected to different ultracentrifugation rates to obtain intramuscular lipid droplets,and red O staining was used to identify intact oil droplets.The lipoprotein was extracted and subjected to coomassie blue staining to identify the high purity of the lipid droplet protein.Western blot was then used to detect the presence of mitochondria,Golgi apparatus,endoplasmic reticulum,and plasma membrane organelles in the lipid droplets to further verify the purity of the lipid droplets.The results showed that the intramuscular lipid droplets of the longissimus dorsi muscle were isolated and purified by ultracentrifugation.The purity of the lipid droplets was verified by morphological observation and Western blotting.This indicates that this method can separate intramuscular lipid droplets with high purity.In order to study the regulation mechanism of intralipid lipid protein on lipid deposition and catabolism in porcine muscle,we used the separation and purification of lipid droplets as an entry point to observe the size and number of intralipid lipid droplets.Western blot technology was used to extract lipid droplet proteins.Detects the level of expression of key factors that regulate lipid droplet metabolism.The results showed that with the increase of body weight of fattening pigs,the volume of intramuscular lipid droplets with a body weight of 120 kg increased,and lipid droplet metabolism-related proteins within the lipid droplets increased significantly.In summary,the “Duroc×Landrace×Yorkshire” ternary cross fattening pigs had a significant increase in the weight of 90 kg intramuscular fat when slaughtered with a body weight of about 120 kg,which improved the pork meat quality and nutritional value.Using ultracentrifugation to separate and purify intramuscular lipid droplets of longissimus dorsi muscle,intramuscular lipid droplets with better morphology and higher purity can be obtained.As the body weight of fattening pigs increases,the volume of intramuscular lipid droplets increases,and the metabolic protein that regulates lipid deposition and degradation on lipid droplets also increases,which together regulates the metabolic balance of lipid droplets.