鳗鱼加工副产物制备抗氧化肽酶解条件的优化

Optimization of Enzymatic Hydrolysis Condition for Preparation of Antioxidant Peptides from Eel Processing By-product

采用响应面方法,对鳗鱼加工副产物制备抗氧化肽的酶解条件进行优化。结果表明,酶与底物蛋白比例(X1)、酶解温度(X2)和酶解时间(X3)与酶解产物抗氧化活性(Y,以酶解液还原力评价)之间满足回归方程:Y=-2.77+0.26X1+0.097 1X2+0.32X3-0.001 27X1X2-0.015 3X1X3+0.000 658X2X3-0.019 4X12-0.093 1X22-0.049X32;该三个因素对酶解产物的还原力均有显著影响(P<0.05),其影响力的大小依次为:X1>X3>X2;X1与X2和X1与X3的交互作用对酶解产物的还原力也有显著影响(P<0.05);过度酶解可导致酶解液还原力的降低;鳗鱼加工副产物制备抗氧化肽的最优酶解条件为:酶与底物蛋白比例为3.84%,50.6℃温度下酶解3 h。经6次验证试验,酶解产物的还原力与预测值无显著差异,酶解产物清除DPPH自由基的EC50值为0.32 mg/mL。

The enzymatic hydrolysis condition for preparation of antioxidant peptides from eel processing by-products were optimized by response surface methodology. The results showed that, the relationship between the antioxidant capacity （Y which evaluated by the reducing power of hydrolysates） of enzymatic hydrolysates and three parameters for enzymatic hydrolysis （ratio of enzyme to substrate protein （X1）, temperature （X2） and time （X3） for enzymatic hydrolysis） could be described with the following regression equation： Y=-2.77＋ 0.26X1＋0.097 1X2＋0.32X3-0.001 27X1X2-0.015 3XIX3＋ 0.000 658XEX3 - 0.019 4X1Z-0.093 1X2Z-0.049X1. All the three independent variables had significant influences on the reducing power of enzymatic hydrolysates （P〈0.05）, and the order of their effects was X1〉X3〉X2. And the interactions between Xt and X2, and between X1 and X3 also had significant influences on the reducing power of enzymatic hydrolysates （P 〈0.05）. Over-hydrolysis of the substrate protein decreased the antioxidant capacity of enzymatic hydrolysates. The optimum enzymatic hydrolysis conditions for preparation of antioxidant peptides from eel processing by-products were as follows： the ratio of enzyme to substrate protein was 3.84%, the temperature of enzymatic hydrolysis was 50.6 ℃, and 3 h for hydrolysis. The optimized parameters of enzymatic hydrolysis were verified by 6 duplicated experiments. No significant difference between the predicted reducing power and the actual reducing power of enzymatic hydrolysates was found. And the ECso of DPPH radical scavenging of the enzymatic hydrolysates was 0.32 mg/mL.