Abstract: The enzymatic hydrolysis of whey protein concentration for preparing antioxidant peptides was optimized using one-factor-at-a-time and orthogonal array design methods. The independent variables selected were temperature, pH, substrate concentration, and enzyme-to-substrate ratio. The responses were degree of hydrolysis, 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide anion radical scavenging capacity, and ion chelating capacity. The optimal hydrolysis conditions were found to be hydrolysis at 60 ℃ and pH 8.5 at a substrate concentration of 2.5 g/100 mL with an enzyme-to-substrate ratio of 3.5％. Furthermore, the optimized values of process parameter were experimentally validated.

Key words: whey protein; antioxidant peptide; enzymatic hydrolysis; process optimization

摘要： 以乳清蛋白为原料,采用酶法水解,分析酶解温度、pH值、底物浓度和酶底比对复合酶水解乳清蛋白的影响,通过单因素试验确定各因素的最适工艺参数,再通过正交试验及验证实验进一步确定乳清蛋白的最佳酶解条件。结果表明:根据单因素试验结果,并综合考虑水解度、1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基清除率、超氧阴离子自由基清除率和铁离子螯合能力4项指标的正交试验结果,最终确定乳清蛋白的最佳酶解条件为酶解温度60℃、pH 8.5、底物质量浓度2.5 g/100 mL、酶底比3.5％。以上述最佳参数为酶解条件进行验证实验的结果表明,验证实验结果与正交试验结果相符,进一步验证了本研究确定的酶解条件为最佳条件。

关键词: 乳清蛋白; 抗氧化肽; 酶解; 工艺优化