酪蛋白的胰蛋白酶水解物分离及其抗氧化性研究

采用胰蛋白酶水解酪蛋白，使用D201阴离子交换树脂对酪蛋白酶解液进行分离，并收集5个多肽片段（P1、P2、P3、P4、P5），评价酪蛋白酶解液及分离所获得的酪蛋白多肽的抗氧化性。结果表明，酪蛋白多肽的还原力和DPPH自由基清除力均显著高于酪蛋白酶解液（P＜0.05）；多肽P2的还原力最高，为0.234，然后是多肽P3，为0.057；多肽P4的DPPH自由基清除活力最高，达到（23.8±0.18）%，然后是多肽P3，为（4.5±0.16）%；多肽P5的Fe2+螯合率最高，为（99.80±0.12）%，多肽P3的Fe2+螯合率最低，为（2.50±0.14）%，而酶解液的Fe2+螯合率为（31.27±5.80）%；多肽P2和P3不具备脂质过氧化抑制力。多肽P1、P4、P5具有较好的抗氧化性。

Separation and antioxidant activity of casein enzymatic hydrolysate by trypsin

When casein was hydrolyzed by trypsin, the casein enzymatic hydrolysate was separated by D201 anion exchange resins, and five polypeptide fragments (P1, P2, P3, P4 and P5) were collected. The antioxidant activity of casein polypeptide obtained by separating and hydrolysate was evaluated. The results showed that the reducing power and DPPH radical scavenging power of casein polypeptide were significantly higher than that of casein enzymatic hydrolysate. The casein polypeptide P2 had the highest reduction power of 0.234, followed by casein polypeptide P3 (0.057). The casein polypeptide P4 had the highest DPPH radical scavenging activity of (23.8±0.18)%, followed by casein polypeptide P3 of (4.5±0.16)%. The casein polypeptide P5 had the highest Fe2+ chelating ability of (99.80±0.12)%, the casein polypeptide P3 had the lowest Fe2+ chelating ability of (2.50±0.14)%, and the chelating ability of enzymatic hydrolysate was (31.27±5.80)%. The casein polypeptide P2 and P3 had no inhibition of lipid peroxidation. The casein polypeptide P1, P4 and P5 had good antioxidant activity.