萝卜籽粕中蛋白质的提取及抗氧化活性研究

摘要

Protein in radish seed meal was extracted by alkali extraction and acid precipitation method,and the optimal extraction conditions were obtained by single factor experiment and orthogonal experiment.The antioxidant activity of the protein was studied and the relative molecular weights of protein components were determined by SDS-PAGE method.The results showed that the optimal extraction conditions of protein in radish seed meal were obtained as follows:ratio of material to liquid 1 ∶ 50,alkali extraction pH 10,extraction temperature 60 ℃,extraction time 90 min and acid precipitation pH 4.5.Under these conditions,the extraction rate of protein was 80.2％ and the protein purity was 89.5％.The protein had good scavenging ability on DPPH ·,NO2-,H2O2 and · OH.There were about five subunits in protein,the relative molecular weights of four kinds of subunit separation components from small to large were 22.0,31.0,43.0,66.2 kDa respectively,and the relative molecular weight of one subunit separation component was 66.2-97.4 kDa.%采用碱溶酸沉法提取萝卜籽粕中的蛋白质,通过单因素试验和正交试验确定最佳的提取条件;对蛋白质的抗氧化活性进行研究;采用SDS-PAGE法测定各蛋白质组分相对分子质量分布.结果表明:萝卜籽粕中蛋白质的最佳提取条件为料液比1∶50、碱溶pH 10、提取温度60℃、提取时间90 min、酸沉pH4.5,在此提取条件下,蛋白质提取率可达80.2％,蛋白质纯度为89.5％;萝卜籽粕中蛋白质对DPPH·、NO;、H2O2、·OH具有很好的清除能力;萝卜籽粕中蛋白质约有5种亚基分离组分,其中4种亚基分离组分相对分子质量由小到大分别约为22.0、31.0、43.0、66.2 kDa,1种亚基分离组分的相对分子质量在66.2～ 97.4 kDa之间.