Effects Of Different Oxidation Systems On Biochemical Characteristics And Texture Of Myofibrillar Protein During Beef Ripening

Protein is the main nutrient component in meat.Myofibrillar protein accounts for about 55%to 60%of the total protein in meat.Its structure and functional properties have an important impact on the nutritional and sensory quality of meat.A large number of studies have confirmed that meat undergoes oxidative modification during the post-mortem maturation and storage process,causing different degrees of oxidative damage to proteins,mainly due to oxidation of fat,metal ions and endogenous oxidants.Caused.In this study,the longissimus dorsi of the male carp in Gannan Prefecture of Gansu Province was used as the research object.The hydroxyl radical oxidation and high-myoglobin oxidation system were established by simulation to study the changes of the biochemical characteristics of myofibrillar protein.The changes of texture and microstructure of yak beef caused by different oxidative strengths,explore the intrinsic relationship between protein oxidation degree and structural changes,in order to clarify the mechanism of protein oxidation during glutinous beef production and processing,effectively regulate the degree of protein oxidation and improve Provide a theoretical reference for meat quality.1.During the maturation of yak meat,varying degrees of oxidation lead to changes in the properties and structure of myofibrillar proteins.During the 28-day maturity of yak,the carbonyl content of protein reached the maximum at the 14th day,which was18.16 nmol/mg protein,and then decreased slightly.Under the high concentration and medium concentration oxidation treatment,the sulfhydryl content decreased rapidly.Compared with the control group,there was a significant difference?P<0.01?;while the disulfide bond content changed in the opposite direction.Oxidation also resulted in a significant increase in Ca-ATPase activity and MFI,while a significant decrease in K-ATPase activity.The surface hydrophobicity gradually increased with the increase of oxidative strength,but did not produce significant difference with the prolongation of maturity time.At the same time,the oxidative maturation caused the texture properties of yak beef to change,and the hardness,cohesiveness and adhesiveness increased significantly.The recovery power is significantly reduced.2.In the oxidative system of hydroxyl radical incubation,the content of carbonyl in the fibrillin of yak beef increased significantly with the increase of H₂O₂concentration;the change of the properties of myofibrillar protein after oxidation increased the surface hydrophobicity;0⁰.5 mmol/L The protein disulfide bond,dimeric tyrosine content,MFI and Ca-ATPase activity of H₂O₂ treatment also increased significantly,and the greater the concentration of H₂O₂,the stronger the degree of protein oxidation.Total sulfhydryl content and K-ATPase activity decreased significantly with increasing H₂O₂ concentration.3.In the high-iron myoglobin incubation oxidative system,with the increase of MetMb concentration,the carbonyl content of yak muscle myofibrillar protein increased significantly,Ca-ATPase activity,dimeric tyrosine,disulfide bond content,surface hydrophobicity and The MFI increased significantly,and the total sulfhydryl content and K-ATPase activity decreased significantly.The total sulfhydryl group decreased significantly at an oxidative concentration of 0.5 mmol/L;the K-ATPase activity decreased more significantly at high oxidative concentrations.The higher the concentration of MetMb,the greater the degree of oxidation of myofibrillar protein,the severe degeneration of myosin head active sulfhydryl SH₁ and SH₂,and protein unfolding.