紫苏粕酶解工艺优化及其多肽抗氧化稳定性

为更好地利用紫苏粕中的蛋白质资源，采用碱性蛋白酶酶解脱脂紫苏粕制备紫苏粕多肽，以水解度为指标，在单因素试验基础上，采用响应面法优化紫苏粕多肽制备工艺，并对最优条件下制备的紫苏粕多肽进行氨基酸组成和抗氧化稳定性分析。结果表明，最佳酶解工艺为酶解时间8 h、初始pH11.5、底物浓度7.5%、酶解温度60 ℃、加酶量7 000 U/g。在此条件下，酶解液水解度为（23.462±0.237）%。紫苏粕多肽由17 种氨基酸组成，其中精氨酸含量最高，达（286.635±0.357）mg/g。紫苏粕多肽在20～100 ℃、pH2～8 保持较强的抗氧化活性。添加适量NaCl 和葡萄糖有助于增强紫苏粕多肽抗氧化活性，添加2%以上柠檬酸则导致ABTS+自由基清除活性显著下降。综上，该工艺制备的紫苏粕多肽具有良好的抗氧化稳定性，具有进一步开发潜力。

Enzymatic Hydrolysis Process Optimization of Perilla Meal and Antioxidant Stability of Polypeptides

Alkaline protease was used to hydrolyze defatted perilla meal to prepare polypeptides，so as to improve the utilization of the protein resources in perilla meal.With the degree of hydrolysis as the indicator and on the basis of the results of single factor experiments，the polypeptide preparation process of perilla meal was optimized by response surface methodology.Furthermore，the amino acid composition and antioxidant stability of the perilla meal polypeptides prepared under the optimal conditions were analyzed.The results showed that the enzymatic hydrolysis conditions were optimized as follows：enzymatic hydrolysis at initial pH11.5，substrate concentration of 7.5%，60 ℃，and enzyme dosage of 7 000 U/g for 8 h，under which the degree of hydrolysis reached（23.462±0.237）%.The polypeptides of perilla meal were composed of 17 amino acids，among which arginine had the highest content of（286.635±0.357）mg/g.Perilla meal polypeptides maintained a strong antioxidant activity within the ranges of 20-100 ℃and pH2-8.Adding proper amounts of NaCl and glucose enhanced the antioxidant activity of perilla meal polypeptides，and adding more than 2% citric acid decreased the ABTS+ free radical scavenging activity.In conclusion，the perilla meal polypeptides prepared by this process had good antioxidant stability and the potential of further development.