三种蛋白酶酶解核桃饼粕的抗氧化活性研究

Effect of three kinds of protease on the antioxidant activities of walnut cake hydrolysates

该研究以核桃饼粕(WC)、石油醚脱脂核桃饼粕(PEWC)、石油醚及丙酮脱脂核桃饼粕(PEAWC)、核桃饼粕分离蛋白(WCP)、石油醚脱脂核桃饼粕分离蛋白(PEWCP)、石油醚及丙酮脱脂核桃饼粕分离蛋白(PEAWCP)为研究对象,分别采用碱性蛋白酶、胃蛋白酶、胰蛋白酶超声水解,以抗氧化活性为评价指标,筛选最佳的蛋白酶及原料处理方法。结果表明,碱性蛋白酶水解PEWC对OH·、O_2^(-·)和DPPH·清除率最高,分别为18.74%、28.44%和79.96%;胰蛋白酶酶解PEWC的总还原力最大;胰蛋白酶水解PEWCP的OH·和DPPH·清除率最高,分别为21.44%和80.22%,但O_2^(-·)清除率较低;胃蛋白酶水解PEWCP的O_2^(-·)清除率最高,达30.23%;碱性蛋白酶酶解PEWCP的总还原力最大;核桃饼粕经石油醚脱脂后的酶解产物抗氧化活性最高,且以碱性蛋白酶为最佳水解酶。

Using the walnut cake （WC）, petroleum ether defatted walnut cake （PEWC）, petroleum ether and acetone defatted walnut cake （PEAWC）, walnut cake protein （WCP）, petroleum ether defatted walnut cake protein （PEWCP）, petroleum ether and acetone defatted walnut cake protein （PEAWCP） as the research objects, and using antioxidant activity as evaluation indexes, the optimum protease and raw material processing method were screened by three protease （including alkaline protease, pepsase and trypsin） ultrasonic hydrolysis. The results showed that the scavenging rate of PEWC hydrolysate by alkaline protease on OH·, O2^-· and DPPH· were the highest （18.74%, 28.44% and 79.96%, respectively）. The PEWC hydrolysate by trypsin had the highest total reducing power. The scavenging rate of PEWCP hydrolysate by trypsin on OH · and DPPH · were the highest （21.44% and 80.22%, respectively）, but lower scavenging rate on O2^-·. The PEWCP hydrolysate by pepsase on O2 ^-· had the highest scavenging rate （30.23%）. The PEWCP hydrolysate by alkaline protease had the highest total reducing power. The study indicated that the walnut cake after defatted by petroleum ether had the highest antioxidant activity, and the alkaline protease was the optimum hydrolase.