秘鲁鱿鱼皮明胶抗氧化肽的制备及其分子质量分布

Preparation and Molecular Weight Distribution of Gelatin Antioxidant Peptides from Jumbo Flying Squid (Dosidicus Gigas) Skin

目的：基于鱿鱼皮明胶肽的抗氧化活性,优化制备工艺,探究其分子质量分布。方法：分别使用4种蛋白酶水解鱿鱼皮明胶,通过测定体外抗氧化活性来确定最适水解用酶。以DPPH自由基清除率为指标,利用单因素及响应面法优化明胶抗氧化肽的制备工艺,通过Tricine-SDS-PAGE及Sephadex G-25凝胶过滤层析测定明胶肽的分子质量分布。结果：碱性蛋白酶为最适水解用酶,最适水解温度55℃,酶添加量7 000 u/g（E/S）,时间109 min,底物明胶质量分数6%,pH 6.66。此条件下明胶肽的DPPH自由基清除率达93.18%。90%明胶肽的分子质量介于1.4~10 ku之间。

Objective： The hydrolysate of gelatin from squid skin shows antioxidant activity. This study aims to opti- mize the preparation process and explore the molecular weight distribution. Methods： Four different kinds of protease were used to hydrolyze gelatin, and the antioxidant activity of gelatin peptide were measured respectively. Using the scavenging ability on the 1,1-diphenyl-2-picryl-hydrazyl （DPPH） radical, the hydrolysis conditions for preparating the antioxidant peptides from gelatin were optimized by single-factor experiments and response surface methodology, and its molecular weight distribution was explored by Tricine-SDS-PAGE and Sephadex G-25 gel chromatography. Results： The optimal enzyme was alkaline protease, and the optimal hydrolysis conditions were as followers： temperature 55 ℃, enzyme concentration 7 000 U/g （E/S）, time 109min, substrate concentration 6% and pH 6.66, respectively. Under these conditions, the scavenging ability on the DPPH radical of gelatin peptide was up to 93.18%. In addition, the molecular weight of 90% gelatin peptides were distributed from 1.4ku to 10ku.