氯化钙-无花果蛋白酶-猕猴桃蛋白酶体系对兔肉肌原纤维蛋白结构的协同作用

Synergistic Effect of Calcium Chloride-Fig Protease-Kiwifruit Protease Blend as Meat Tenderizer on Myofibrillar Protein Structure of Rabbit Meat

探究氯化钙-无花果蛋白酶-猕猴桃蛋白酶复合体系对肌原纤维蛋白(myofibrillar protein,MP)的协同降解作用,对比经复配组、氯化钙组、猕猴桃蛋白酶组和无花果蛋白酶组处理后的兔肉肌原纤维小片化指数、MP溶解度、可溶性蛋白含量(soluble protein content,SPC)、MP表面疏水性及十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)。结果表明:各项指标中,复配组对MP的降解作用显著高于单一组(P<0.05);单一组中氯化钙显著提高蛋白疏水性(P<0.05);蛋白酶组显著提高蛋白溶解度和SPC(P<0.05);SDS-PAGE显示无花果蛋白酶主要降解肌球蛋白轻链、C蛋白,猕猴桃蛋白酶对肌球蛋白重链降解强烈。上述结果表明复配体系对降解MP具有协同增效作用,其作用机理可能是由于氯化钙诱导MP失去稳定性,MP结构展开,暴露更多酶结合位点,同时由于2种蛋白酶不同的特异性相结合从而加强蛋白降解和增溶作用。

This investigation aimed to study the synergistic effect of a mixed meat tenderizer of calcium chloride,fig protease and kiwifruit protease on the structure of myofibrillar protein in rabbit hind leg meat.We measured and compared the myofibrillar fragmentation index(MFI),myofibrillar protein solubility,soluble protein content(SPC)and sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE)profiles of myofibrillar protein in meat samples treated with each meat tenderizer alone and their combination.The results showed that the mixed tenderizer could degrade myofibrillar protein more effectively than the single tenderizers(P<0.05).The surface hydrophobicity of myofibrillar protein in the calcium chloride group was significantly higher than that in other single treatments(P<0.05).The solubility of myofibrillar protein and SPC in the single enzyme treatments were significantly higher than those in the calcium chloride group(P<0.05).The SDS-PAGE showed that the myosin light chain and C-protein were mainly degraded by fig protease while the myosin heavy chain was mainly degraded by kiwifruit protease.The above results indicate that combined treatment with the meat tenderizers could synergistically enhance the degradation of myofibrillar protein,possibly due to the fact that calcium chloride could make myofibrillar protein unstable,resulting in its unfolding and exposure of more enzyme binding sites,and that the two proteases showed different specific substrate binding patterns prompting protein degradation and solubilization.