仿刺参精酶解工艺的优化及酶解液的抗氧化活性

Optimization of Enzymatic Hydrolysis of Apostichopus japonicus Sperm and Antioxidant Activity of Hydrolysate

作为性腺的仿刺参精富含蛋白质、多糖和多种活性物质,被单独收集并酶解,用于开发新型的海洋活性多肽。选用木瓜蛋白酶水解仿刺参精,以水解度(DH)为评价标准,通过单因素实验和响应面法确定最佳水解条件。当木瓜蛋白酶与底物质量比为4.4%时,在70℃条件下反应4 h,水解度最高可达到43.18%。随后,采用Pall Minimate超滤系统从酶解液中分离梯度肽,得到分子质量范围分别为<1 ku、1~5 ku和5~10 ku的多肽,测定它们对超氧自由基(·O_(2)^(-))和羟基自由基(·OH)的清除效率。抗氧化试验结果显示,分子质量<1 ku的多肽对·O_(2)^(-)的清除能力最强,表明该肽段具有较好的抗氧化活性。仿刺参精的水解产物作为一种具有抗氧化活性的海洋多肽,有望用于保健品、医药和化妆品行业。

As sea cucumber gonad, Apostichopus japonicus(Aj) sperm is rich in protein, polysaccharide and many kinds of active substances. It was collected separately and enzymatically hydrolyzed to develop new marine active peptides. In this paper, papain was chosen for enzymatic hydrolysis and the degree of hydrolysis(DH) was selected as the evaluation standard. The optimal hydrolysis conditions were confirmed through one-factor-at-a-time study and response surface methodology. By using the enzyme-to-substrate ratio at 4.4%, the DH could reach 43.18% in 4 h at 70 ℃.Thereafter, cascade peptides(1 ku, 1-5 ku, and 5-10 ku) were isolated from hydrolysate using Pall Minimate ultrafiltration system and were evaluated as the superoxide radical (·O_(2)^(-)) and hydroxy radical (·OH) scavengers. The antioxidant assays showed that the peptides of 1 ku molecular weight exhibited the best ·O_(2)^(-)scavenging activity. Therefore, the hydrolysate of Aj sperm might be used as a potential antioxidant peptides source for nutraceutical, pharmaceutical and cosmetics industries.