复合酶解牦牛乳酪蛋白工艺优化及抗氧化性的研究

Optimization on enzyme process and antioxidant activity of yak's milk casein polypeptide

为了优化牦牛乳酪蛋白酶解工艺,研究其产物抗氧化活性,选用中性蛋白酶、碱性蛋白酶、胃蛋白酶、胰蛋白酶和木瓜蛋白酶,在其最适条件下酶解牦牛乳酪蛋白,以水解度(DH)、DPPH·自由基清除率和超氧阴离子清除率为评价指标,筛选出2种效果最优的单酶进行复配,采用单因素试验及L9(34)正交试验确定最优酶解工艺。结果表明:中性蛋白酶和胰蛋白酶比例为1:2效果最佳,最佳酶解工艺条件为底物浓度5%(w/v),温度42.5℃,p H值7.5,复合酶添加量3%,作用时间150 min,酶解产物抗氧化活性最高,DPPH·自由基清除率达到了64.26%±0.18%,超氧阴离子清除率达到40.34%±0.92%。

To optimize the enzymatic process of yak＇s milk casein, and the yak＇s milk casein antioxidant peptide was studied. The casein was hydrolyzed by neutral protease, alcalase, papain, trypsin, pepsin. hydrolysis and DPPH radical scavenging activity were used evaluation index, neutral protease and trypsin were used in the compound enzymatic hydrolysate conditions. Using single factor experiment and orthogonal experiments to optimize process condition. The results showed that the compound enzyme hydrolysate optimized conditions： substrate concentration 5%, the ratio of neutral protease and trypsin 1：2, temperature 42.5 ℃, p H 7.5, E/S 3% and hydrolysis time 150 min, under the conditions, DPPH radical scavenging activity was 64.26%±0.18%, O2—· scavenging activity was 40.34%±0.92%.