大豆抗氧化肽的制备及对大蒜根尖过氧化的保护作用

Preparation of soybean antioxidant peptides and their protective effect against garlic root tip peroxidation

为探究不同蛋白酶酶解大豆分离蛋白(soybean isolate protein,SPI)对多肽得率及体外抗氧化活性的影响,采用6种蛋白酶(碱性蛋白酶、木瓜蛋白酶、菠萝蛋白酶、中性蛋白酶、胰蛋白酶、胃蛋白酶)进行筛选,测定酶解产物多肽得率、光谱特性及体外抗氧化能力,分析其对过氧化氢诱导的大蒜根尖氧化损伤的保护作用。结果表明,碱性蛋白酶酶解条件下,多肽得率最高为67.78%;多肽在200~230 nm处有最大吸收峰;6种多肽在酰胺A、B、Ⅰ、Ⅱ、Ⅲ带均有吸收峰;所有多肽均具有较好地清除自由基能力,且随着多肽浓度的增加而增加。综合其抗氧化活性评价,碱性蛋白酶制备的多肽清除能力均优于其他蛋白酶;经多肽处理后大蒜根尖细胞凋亡程度下降45.90%。

In order to investigate the effects of enzymatic hydrolysis of soybean protein isolate with different proteases on the yield of polypeptide and antioxidant activity in vitro,six proteases(alkaline protease,papain,bromelain,neutral protease,trypsin,pepsin)were selected to determine the yield,spectral characteristics and antioxidant capacity of the polypeptide products of enzymatic hydrolysis.The protective effect on oxidative damage of garlic root tips induced by hydrogen peroxide was analyzed.The results show that the highest polypeptide yield was 67.78%under the condition of alkaline protease hydrolysis.The maximum absorption peak of polypeptide was at 200-230 nm.The absorption peaks of the 6 peptides were found in the amide A,B,Ⅰ,ⅡandⅢbands.All peptides have good scavenging ability of free radicals,and the ability increases with the increase of peptide concentration.According to the evaluation of antioxidant activity,the scavenging ability of polypeptide prepared by alkaline protease is better than that of other proteases.The apoptosis of garlic root tip cells decreases by 45.90%after polypeptide treatment.