鱼蛋白酶水解物的钙螯合修饰及其功能活性

Preparation and bioactivity of Ca^(2+) chelate of hydrolysate by enzymolysis from the waste fish proteins

以低值鱼蛋白为原料通过复合酶水解法和钙修饰法获得了蛋白质酶水解物的修饰产物并对其功能活性进行了初步研究。结果表明,未脱脂的鱼蛋白酶水解物钙螯合修饰的最适宜条件为蛋白质水解度为5%、螯合pH为7.0、螯合温度为20℃、螯合完成时间为15min;无水乙醇分级分离可获得三种螯合组分,水不溶组分(CA)、50%无水乙醇不溶性组分(CB)和80%无水乙醇不溶性组分(CC);红外光谱分析表明,CA的钙紧密地与氨基和羰基基团结合形成螯合修饰物,并以钙为中心形成五元环,而CB和CC组分中钙只与羰基紧密结合形成环状结构;在这些螯合物组分中,CA具有最高的抗氧化活性,且高达α-生育酚的94%,而CC具有最高的抗大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌的活性,并发现抗菌活性大小与组分的水溶性和分子中电子中继系统的电子缓冲能力有关。本文的研究可望对海洋低值鱼蛋白质的高效利用和蛋白质的酶水解物经螯合修饰后作为食品添加剂在食品工业中的应用奠定理论基础。

This paper focuses on the preparation and bioactivity of Ca^2＋ chelate of hydrolysate from the waste fish proteins through compound enzymolysis. The optimum formation conditions of the hydrolysate chelating Ca^2＋ are 5% of DH, 7.0 of pH, 20 ℃ of temperature and 15 rain of chelating time for FM （material not being defatted）. Three types of hydrolysate chelating Ca^2＋ including CA （deposit after chelating）, CB （deposit in 50% of absolute alcohol solution） and CC （deposit in 80% of absolute alcohol solution） were obtained through fractional precipitation with absolute alcohol from FM. Structure analysis through IR revealed that Ca^2＋ had been combined strongly with amino-group and carboxyl-group in each of chelates and each of Ca^2＋ could form 2 five-membered ring structures in CA, however, Ca^2＋ had been only combined strongly with carboxyl-group in CB and CC. Among all of the chelates, the CA possesses the most effective antioxidative activity and the activity is 94% as high as that of a-tocopherol, and only CC possesses the most effective antibacterial activity against E. coli, S. aureus and B. subtilis and the activity depends on the size of the dissolvability in aqueous system and the strength of the electron buffering capability of the electron relaying system for CC. These researches provide a more effective way for the utilization of waste fish proteins and the essential information for the enzymatically hydrolyzed waste fish protein chelating Ca^2＋ as additive in food industry.