中文摘要：

为获得制备银杏抗氧化肽的最佳工艺,采用2709碱性蛋白酶和胃蛋白酶分步水解银杏种仁蛋白,以总还原能力为指标,考察酶用量、酶解温度、pH值和酶解时间这4个因素对银杏种仁蛋白酶解效果的影响。通过响应面试验得出2709碱性蛋白酶的最佳酶解工艺为：酶用量为6976U/g、酶解温度为55℃、pH值为8.9、酶解时间为5h,此时银杏种仁蛋白酶解液的总还原能力（A700nm）为1.278;通过正交试验,得到胃蛋白酶的最佳酶解工艺为：酶用量为9000U/g、pH值为3.0、酶解温度为50℃、酶解时间为2h,此时银杏种仁蛋白酶解液的A700nm为1.636。

英文摘要：

In the present study,the preparation of antioxidant peptides derived from Ginkgo biloba kernel by stepwise enzymatic hydrolysis with alkaline protease 2709 and pepsin was optimized.Four process conditions affecting total reducing power activity of antioxidant peptides including enzyme dosage,temperature,pH and hydrolysis time were investigated.Using response surface methodology,the optimal conditions for hydrolysis of alkaline protease 2709 were determined as follows： 6976 U/g enzyme dosage,55 ℃ hydrolysis temperature,pH 8.9 and 5 h hydrolysis time,and the total reducing power activity（expressed as absorbance at 700 nm,A700 nm） of the resulting hydrolysate was 1.278.For the subsequent pepsin hydrolysis,the optimal hydrolysis conditions were determined using orthogonal array design to be： 9000 U/g enzyme dosage,pH 3.0,50 ℃ hydrolysis temperature and 2 h hydrolysis time,and the resulting reducing power A700 nm was 1.636.