鱼鳞抗氧化肽的酶法制备工艺及特性

Enzymatic Preparation and Characterization of Antioxidant Peptides from Grass Carp Scales

采用碱性蛋白酶(alcalase)水解草鱼鱼鳞制备鱼鳞抗氧化肽。用单因素及正交试验考察温度、加酶量、底物水平、酶解时间等因素对酶解反应的影响,确定最适条件。以肽得率、水解度和对羟自由基清除率为考察指标,得出酶解草鱼鱼鳞的较佳工艺条件为温度55℃、底物水平10%、加酶量3%、时间5h、pH9.0;此时酶解液中鱼鳞肽得率为55.2%,羟自由基清除率为98.86%;高效液相色谱法测定鱼鳞抗氧化肽的相对分子质量排布,分子质量在1000D以下的占91.8%,等电点为2.6左右,在pH2～12的条件下溶解度均在98%以上,可广泛应用于食品中。

The enzymatic hydrolysis of grass carp scales with alcalase for the preparation of antioxidant peptides was optimized by one-factor-at-a-time and orthogonal array design methods.Peptide yield,hydrolysis of degree（DH） and hydroxyl free radical scavenging rate of grass carp scale hydrolysate were investigated with respect to temperature,enzyme dose,substrate concentration,reaction time.The optimal hydrolysis conditions were pH 9.0,hydrolysis temperature of 55 ℃,enzyme amount of 3%,hydrolysis time of 5 h and substrate concentration of 10%,respectively.Under these conditions,the yield of peptides was 55.2% and the resultant hydrolysate presented a hydroxyl free radical scavenging rate of 98.86%.High performance liquid chromatography analysis showed that 91.8% of peptides in the hydrolysate had a molecular weight below 1000 D.The hydrolysate had an isoelectric point of around 2.6 and a solubility of higher than 98 % in the range of pH 2-12 and could thus be extensively used in foods.