不同分子质量米糠多肽的抗氧化活性  

Antioxidant Activity of Rice Bran Polypeptide with Different Molecular Weights

作　　者：张敏[1] 周梅[2] 

机构地区：[1]北京工商大学食品学院,北京100037 [2]东北农业大学食品学院,黑龙江哈尔滨150030

出　　处：《食品科学》2013年第3期1-6,共6页Food Science

基　　金：国家自然科学基金项目(31101387);"十二五"国家科技支撑计划项目(2012BAD34B00)

摘　　要：采用截留分子质量为10000、3000D超滤膜对碱性蛋白酶水解米糠蛋白的水解液进行分离,获得不同分子质量(Mw)的米糠多肽混合物组分,以6种抗氧化活性指标对米糠多肽混合物组分的抗氧化活性进行评价。结果表明:米糠多肽的抗氧化活性与蛋白分子质量大小密切相关。Mw>10kD的米糠多肽对.OH的清除能力最强,属于活性氧自由基清除的抗氧化机制;Mw3～10kD的米糠多肽对Fe3+螯合能力最强,属于金属离子螯合的抗氧化机制;Mw<3kD的米糠多肽对O-2.的清除能力、DPPH自由基的清除能力、ABTS+.清除能力和Fe3+还原能力最强,属于电子转移(SET)的抗氧化机制。不同分子质量的米糠多肽抗氧化活性随多肽质量浓度的增加而增加。Ultrafiltration membranes with molecular weight cut-off （MWCO） of 10000 D and 3000 D were applied to isolate alkali protease in rice bran protein and obtain polypeptide mixture components with different molecular weights. The antioxidant activity of each fraction obtained was assessed by determining six indicators. Results indicated that the antioxidant activity of rice bran protein hydrolysates was correlated with their molecular weights. Rice bran ploypeptides with molecular weight above 10 kD had the strongest radical scavenging capacity, while those with molecular weight in the range of 3--10 kD had the strongest Fe3＋-chelating capacity. Rice bran polypeptides with molecular weight below 3 kD had the best scavenging capacity against superoxide anion, DPPH radical and ABTS＋ and the most potent Fe3＋ reducing capacity, which was based on single electron transfer （SET） reactions. The antioxidant activity of rice bran protein polypeptides with different molecular weights was directly proportional to concentration.

关 键 词：米糠蛋白 米糠多肽 分子质量 抗氧化活性 抗氧化机制 

分 类 号：TS201.4[轻工技术与工程—食品科学]