采用不同蛋白酶酶解乳清浓缩蛋白,以DPPH自由基清除率评价抗氧化活性,确定胰蛋白酶为最佳酶源。依次采用大孔吸附树脂、凝胶层析、制备型和分析型反相高效液相色谱分离纯化酶解物,最后得到A3a和A3b两个纯化多肽,经Q-TOFMS分析得到氨基酸序列为LDGNAKPTPEGDLEL和LYEDLKPTPEGPMEL。A3a和A3b的DPPH自由基清除IC50分别为2.51和4.95μg/mL。结果表明,乳清蛋白抗氧化肽具有较小分子量和特定氨基酸序列,能够有效清除自由基,可作为食源性抗氧化剂。

Different proteases were employed to produce antioxidative peptides derived from whey protein concentration.The antioxidant activities were investigated using DPPH radical scavenging activity.The enzymatic hydrolysates hydrolyzed with Trypsin showed the highest antioxidant activity.After isolation by macroporous adsorption resin,Sephadex G-15 gel filtration column,preparative and analytic RP-HPLC,two peptides named A3a and A3b were obtained with the IC50 were 2.51 and 4.95 μg/mL,respectively.Identified by Q-TOF MS,the amino acid sequence of m/z 1568.70 of A3a was LDGNAKPTPEGDLEL,while m/z 1731.70 of A3b was LYEDLKPTPEGPMEL.The findings are significant in the discovery and development of natural antioxidants from whey protein.