核桃多肽的制备工艺优化及抗氧化活性研究

Optimization of Hydrolysis Preparation Process of Walnut Proteins and Antioxidant Activities of Its Hydrolysates

试验以核桃蛋白粉为原料,分别采用木瓜蛋白酶、中性蛋白酶、风味蛋白酶以及碱性蛋白酶进行酶解。对影响酶解的主要因子pH、酶解温度、加酶量以及底物浓度进行单因素试验,采用响应面法优化核桃多肽的水解工艺。结果表明:在pH 9.0,温度53℃,加酶量7 430 U/g底物以及底物浓度为2.2%时达到最佳。在此条件下,三次重复验证性试验测得核桃蛋白水解度为14.54%±0.32%。该工艺制备的核桃多肽抗氧化试验表明,其清除·OH和DPPH自由基的IC_(50)值分别为15.43和18.38 mg/m L,是一种优良的抗氧化多肽,具有广阔的市场前景。

Walnut protein powder was used as the raw material,was hydrolyzed by four protease（papain,neutral protease,flavor protease and alkaline protease）.Then single factor experiment was carried out to research the effects of the factors such as hydrolysis p H,hydrolysis temperature,enzyme dosage,substrate concentration and hydrolysis process optimization of walnut polypeptide by response surface method.The results showed that the optimum conditions were p H 9.0,temperature 53 ℃,enzyme dosage 7 430 U/g and substrate concentration 2.2%.Under the conditions,through three validation tests,the actual hydrolysis degree of walnut protein degree of hydrolysis was 14.54%±0.32%.The antioxidant test of walnut polypeptide prepared by this process showed that the IC（50） value of scavenging free ·OH and DPPH radical were15.43 mg/m L and 18.38 mg/m L,respectively,and it was an excellent antioxidant polypeptide with broad market prospect.