Abstract: In order to prepare the hypophthalmichthys molitrix skin peptides with good antioxidant activity, the hypophthalmichthys molitrix skin was hydrolyzed by using of the four common commercial enzymes, namely, trypsin, Alcalase 2.4L, bromelain and papain; ABTS radical scavenging activity and ferrous ion-chelating activity were determined; and the hydrolyzates were separated by ultrafiltration and gel chromatography to obtain better hydrolyzate separation fractions. The results showed that the antioxidant activity of the protein hydrolysate increased, among which the antioxidant activity of the protein hydrolysate after a 2-hour enzymolysis had a stronger antioxidant activity. An ultrafiltration was carried out to the hollow fiber ultrafiltration membranes with the cut-off molecular weight of 10 kDa, 5 kDa and 3 kDa. Among the 4 fractions after the ultrafiltration., the smaller the molecular weight was, the stronger the antioxidant activity was. The fraction with a molecular weight less than 3 kDa was separated into 3 sub-fractions by Sephadex G-15 gel chromatography, among which the larger the molecular weight was, the stronger the antioxidant activity was, whose ABTS radical scavenging ability (79.65±0.87)% and Fe2+ chelating capacity (93.40±0.20)% were determined at the concentration of 0.51 mg/mL. This study provided a theoretical reference for the exploitation and utilization of antioxidant peptides from hypophthalmichthys molitrix skin.

Key words:  hypophthalmichthys molitrix skin, enzymatic hydrolysis, antioxidant activity, ultrafiltration, gel chromatography

摘要： 为制备抗氧化活性良好的鲢鱼鱼皮蛋白肽，采用胰蛋白酶、碱性蛋白酶、菠萝蛋白酶和木瓜蛋白酶等4种常见的商业酶对鲢鱼鱼皮进行酶解，测定酶解物的ABTS自由基清除力和Fe2+螯合力来评价其抗氧化活性，并用超滤及凝胶层析对酶解物进行分离，以期得到活性更好的酶解物分离组分。酶解后产物的抗氧化活性均有所提高，其中碱性蛋白酶酶解2 h产物活性较强。对此酶解物用截留分子量为10 kDa、5 kDa和3 kDa的中空纤维超滤膜进行超滤，得到的4个组分中，分子量越小的组分抗氧化活性越强。分子量小于3 kDa的组分经Sephadex G-15凝胶层析得到3个组分，其中分子量最大的组分活性较好，在0.51 mg/mL质量浓度下测定其ABTS自由基清除率和Fe2+螯合力分别为(79.65±0.87)%和(93.40±0.20)%。该研究成果对鲢鱼鱼皮抗氧化肽的开发具有较好的指导作用。

关键词: 鲢鱼鱼皮, 酶解, 抗氧化活性, 超滤, 凝胶层析