酶解牡丹籽粕蛋白制备抗氧化肽的工艺优化

利用制备的牡丹籽粕蛋白为原料,对其进行酶解以获得具有抗氧化活性的多肽,为牡丹籽粕的精深加工提供理论依据。首先进行蛋白酶的筛选,选取最佳的碱性蛋白酶对碱溶酸沉法制备的牡丹籽饼粕蛋白进行酶解;以水解度和DPPH自由基清除力为指标进行单因素实验,分别考察底物浓度、酶解时间、加酶量、pH和酶解温度对制备抗氧化活性肽的影响;以DPPH自由基清除力为响应值,对牡丹籽粕蛋白抗氧化肽的制备工艺进行响应面法优化,确定的最佳制备工艺为:底物浓度0.7%、酶解时间2 h、酶用量4.60%、酶解温度56℃和pH8.0。抗氧化实验结果表明,制备的抗氧化肽对DPPH自由基的清除率为52.49%;经17种水解氨基酸组成分析证明,必需氨基酸占水解氨基酸总量的32.24%,具有较高的营养价值。

Optimization of process for preparation of antioxidant peptides by enzymatic hydrolysis of protein prepared from peony seed meal

The protein prepared from peony seed meal was subjected to hydrolysis to prepare the antioxidant peptides in order to providing a theoretical basis for the deep processing of peony seed meal.Firstly,the type of proteases was screened then alcalase was selected to hydrolyse the protein isolated from peony seed meal by alkaline-solubilization and acid-precipitation method. Then hydrolysis degree and DPPH free radical scavenging capacity were used as the response values to investigate the effects of single-factors including substance concentrations, hydrolysis time, enzyme dosage, enzymolysis temperature and pH on the activity of prepared antioxidant peptides. The optimal parameters for the preparation of antioxidant peptides from peony seed meal protein through response surface analysis were obtained as follows:substance concentration 0.7%,hydrolysis time 2 h, enzyme dosage 4.60%, enzymolysis temperature 56℃ and pH8.0, with a DPPH radical scavenging ratio of 52.49% for the prepared antioxidant peptides from peony seed meal protein.The analysis of amino acid composition of 17 kinds of hydrolysis showed that the essential amino acids accounted for 32.24% of the total amount of amino acids hydrolyzed, and the peony peptides have a high nutritional value.