苜蓿多肽制备工艺优化及其抗氧化活性

以苜蓿(Medicago sativa)为原料,对碱性蛋白酶添加量、酶解时间、酶解温度、酶解pH四个因素进行单因素实验,通过响应面法对苜蓿多肽的酶解工艺进行优化。结果表明,最佳酶解工艺条件为:加酶量3000 U/g,酶解pH8.79,酶解温度49.9 ℃,酶解时间4.9 h,得到多肽含量为4.94 mg·mL-1。在该条件下,1 mg·mL-1样品对羟自由基和超氧阴离子自由基的清除能力较强,分别为74.61%和72.14%,对DPPH自由基清除能力较弱,为61.53%,说明苜蓿多肽具有良好的抗氧化活性,为苜蓿进一步开发利用提供理论依据。

Optimization of Preparation Technology and Antioxidant Activities of Alfalfa Polypeptide

Alfalfa was used as the material. The effects of neutral protease addition, enzymolysis time, enzymatic hydrolysis temperature and enzymatic hydrolysis pH by single factor experiments were studied and were optimized by the response surface method. The results showed that the optimal enzyme solution were enzyme concentration of 3000 U/g, pH value 8.79, enzymatic hydrolysis at 49.9℃ and enzymolysis time of 4.9 h, and the peptides content was 4.94 mg·mL-1. Under the optimal enzymolysis conditions, the 1 mg·mL-1 peptides sample had a strong scavenging capacity against hydroxyl and superoxide anion, the scavenging rate were 74.61% and 72.14%, with weak DPPH radical scavenging capacity. The results indicated that peptides of alfalfa exhibited good antioxidant activity. These results would provide theoretical supports for the further development of alfalfa.