麦胚蛋白水解物抗氧化活性及其作用模式

采用中性蛋白酶水解麦胚蛋白0.5～6 h,测定水解物的DH(degree of hydrolysis)、硫代巴比妥酸值(TBARS值)、POV值(Prroxide value)、Cu2+螯合能力、二苯代苦味肼基自由基清除能力(DPPH自由基)。结果表明,麦胚蛋白水解度随着水解时间的延长而增加;水解物5 h与未水解的蛋白及0.02%VC相比,在大豆卵磷脂脂质氧化体系(Liposome体系)中具有较强的抑制脂质氧化的能力,还具有较强的Cu2+螯合能力和清除自由基能力,未水解的蛋白具有较弱的抗氧化能力;通过对未水解的麦胚蛋白及不同浓度蛋白水解物的抗氧化指标测定和分析,认为水解物的抗氧化活性与蛋白本身的结构、肽链长短及氨基酸残基有关。

Study on Antioxidant and Mechanism of Wheat Germ Hydrolysates

Wheat germ protein was hydrolyzed for 0.5~6 h by neutral protease,and degree of hydrolysis(DH)increased with hydrolysis time.Wheat germ protein hydrolysates′s DH,Thiobarbituric acid-reactive substance values,peroxide,Cu2+ chelation ability and radical-scavenging ability were mensurated.The result demonstrated that neutral protease-hydrolyzed wheat germ protein exhibited a stronger antioxidant activity than non-hydrolyzed protein and 0.02% VC,as indicated by peroxide and TBARS values in a liposome-oxidizing system.And possess strong Cu2+ chelation ability and radical-scavenging ability.Antioxidant mechanism of hydrolysates was analyzed,as what antioxidant index of non-hydrolyzed wheat germ protein and hydrolysates with different concentration were mensurated.The antioxidant effectiveness of the protein hydrolysates appeared to depend on specific structure,type of peptides,and ratio of different freed amino acids.