Mechanism Study On The Effects Of L-Arginine And L-Lysine On Myosin Oxidation And Its Emulsifying Properties

Protein oxidation is one of the main causes that impairs the quality properties,nutritional value and safety of meat and meat products.Therefore,to develop safe and effective natural antioxidants would be of great significance to inhibit the oxidation of proteins in meat and meat products.In this study,a hydroxyl radical-generating system(HRGS)was established.First,the effects of L-arginine(Arg)and L-lysine(Lys)on protein oxidation of emulsion sausages under oxidizing conditions were investigated;On this basis,the influence mechanism of Arg and Lys on the emulsifying properties of myosin under oxidizing conditions was further studied.The preliminary conclusions are as follows:1.The effects of Arg and Lys on protein oxidation of emulsion sausage(1)Compared with the individual addition of oxidizing system,the further additionof Arg and Lys can significantly increase the L* value and a* value of emulsionsausage and significantly decrease the cooking loss of emulsion sausage.(2)The addition of Arg and Lys can significantly improve the emulsion stability,p H value and texture of emulsion sausage.(3)Arg and Lys can effectively suppress the oxidation-induced increase of thecarbonyl content and the decrease of the total sulfhydryl content of theemulsion sausage.(4)Confocal laser scanning microscopy results showed that,compared with theindividual addition of oxidizing system,the further addition of Arg and Lysdecreased the droplet size of fat particles of emulsion sausage,and the proteingel network structure of emulsion sausage was more uniform and denser.2.Study on the effects of Arg and Lys on the emulsifying properties of myosinunder oxidizing conditions(1)Arg and Lys can effectively inhibit the decreases of emulsifying activity andemulsion stability as well as the increases of creaming index and particle size ofmyosin-soybean oil emulsion which were prepared from oxidatively stressedmyosin.(2)Confocal laser scanning microscopy analysis showed that Arg and Lys caneffectively inhibit the aggregation of oil droplets as well as the aggregation ofmyosin of myosin-soybean oil emulsion prepared by oxidized myosin.(3)The addition of Arg and Lys can effectively inhibit oxidation-inducedincreases of carbonyl content,β-sheet content and surface hydrophobicity ofmyosin,and interfere oxidation-induced decreases of total sulfhydryl content,α-helix content,endogenous fluorescence intensity and solubility of myosin.Arg can effectively hinder oxidation-induced increase of dityrosine content ofmyosin.Arginine and lysine may maintain the emulsifying properties of meat proteins by inhibiting the effects of oxidation on its structure,and ultimately improve the physical and chemical properties of emulsion sausages,which may help extend the shelf life of emulsion sausages.