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目的研究蛋清蛋白肽抗氧化作用模式。方法利用超滤技术分离蛋清蛋白木瓜蛋白酶酶解产物;采用Fenton体系、邻苯三酚自氧化体系和亚油酸自氧化体系分别测定超滤各组分清除羟自由基、超氧阴离子及抑制脂质过氧化的能力,同时测定各组分对二苯代苦味肼基自由基清除能力(DPPH自由基)、还原能力及对猪胎儿成纤维细胞(porcine embryonic fibroblast,PEF)过氧化损伤的保护作用。结果超滤各组分中分子量小于3kDa组分(蛋清蛋白酶解产物-Ⅲ,egg white protein hydrolysate,EWPH-Ⅲ)占蛋清蛋白酶解产物(EWPHs)总量的50.06%。EWPH的抗氧化活性随分子量的降低而增强(P<0.05),其中EWPH-Ⅲ在浓度为5mg/mL时,对羟自由基、超氧阴离子、DPPH自由基的清除率分别为52.86%、35.05%和78.74%,对亚油酸氧化的抑制率为74.57%。在浓度为2.5mg/mL时,PEF细胞存活率达到70.06%。结论蛋清蛋白肽具有较强的抗氧化活性且分子量越小,抗氧化活性越强,可以作为氢供体、自由基稳定剂和金属离子螯合剂来抑制过氧化作用。
Objective To study the anti-oxidative mode of egg white protein peptide. Methods The enzymatic hydrolyzate of egg white protein was separated by ultrafiltration. The hydroxyl radicals, superoxide anion and lipid peroxidation were determined by Fenton system, pyrogallol autoxidation system and linoleic acid autoxidation system respectively. Peroxidation and DPPH free radical scavenging activity, the reducing ability and the protective effect on the peroxide-induced oxidative damage in pig porcine embryonic fibroblasts (PEF) . Results The fraction of molecular weight less than 3 kDa (egg white proteolytic product-Ⅲ, egg white protein hydrolysate, EWPH-Ⅲ) in the fraction of ultrafiltration accounted for 50.06% of the total amount of protein hydrolyzate (EWPHs). The antioxidant activity of EWPH increased with the decrease of molecular weight (P <0.05). The EWPH-Ⅲ scavenging rates of hydroxyl radical, superoxide anion and DPPH radical were 52.86% and 35.05 respectively at the concentration of 5mg / mL % And 78.74% respectively. The inhibition rate of linoleic acid oxidation was 74.57%. At a concentration of 2.5 mg / mL, PEF cell survival rate reached 70.06%. Conclusion Egg albumin peptide has a strong antioxidant activity and the smaller the molecular weight, the stronger the anti-oxidative activity. It can be used as a hydrogen donor, a free radical stabilizer and a metal ion chelator to inhibit the peroxidation.