基于乳清蛋白粉水解产物抗氧化活性优化酶解工艺

通过提高乳清蛋白粉水解产物(Whey protein powder hydrolysate,WPPH)的抗氧化活性,对乳清蛋白粉的酶解工艺进行优化。首先以WPPH水解度及抗氧化活性(1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、羟自由基清除率、总抗氧化能力)为指标,从4种蛋白酶中筛选得到酶解效果较好的胰蛋白酶和菠萝蛋白酶。然后通过单因素与正交试验确定双酶协同水解乳清蛋白粉的最适酶解条件。结果表明:复合酶最优酶解条件为菠萝蛋白酶和胰蛋白酶以1:1的比例同时添加,pH6.0、温度50℃、酶底比0.3%、底物浓度3 g/100 mL、酶解时间2.5 h,在此条件下WPPH水解度达到34.24%,分子量低于1000 Da的肽段占比在50%以上,DPPH自由基清除率91.42%±0.51%、羟自由基清除率80.85%±0.47%、总抗氧化能力(46±0.65)μmol/L。在本研究确定的酶解工艺条件下,乳清蛋白粉水解产物具有较强的抗氧化活性,在天然抗氧化剂和保健食品领域有一定的开发利用价值。

Optimization of Enzymolysis Technology of Whey Protein Powder Hydrolysate Based on Its Antioxidant Activity

To improve the antioxidant activity of whey protein powder hydrolysates(WPPH),the enzymolysis technology of WPPH was optimized. WPPH hydrolysis degree and antioxidant activity(1,1-diphenyl-2-picrylhydrazol(DPPH) free radical scavenging rate,hydroxyl radical scavenging rate and total antioxidant capacity) as the indexes,trypsin and bromelain with better hydrolysis effect were screened out from four kinds of protease. And the processing was optimized by single factor and orthogonal experiments. The results showed that the optimal enzymatic conditions for the complex enzyme were bromelain and trypsin added at a ratio of 1:1 at the same time,pH6.0,temperature 50℃,enzyme material ratio 0.3%,substrate concentration 3 g/100 mL,and hydrolysis time 2.5 h. Under these conditions,the degree of WPPH hydrolysis reached 34.24%. The peptides with molecular weight below 1000 Da was over 50%. DPPH free radical scavenging rate was 91.42%±0.51%,hydroxyl radical scavenging rate was 80.85%±0.47%,antioxidant capacity(46±0.65) μmol/L. Under the enzymatic conditions determined in this study,the whey protein powder hydrolysate has strong antioxidant activity,which makes certain development and utilization value in the field of natural antioxidants and health foods.