米糟蛋白酶解制备生物肽及其抗氧化活性的研究

为了高值化利用米糟资源,以米糟蛋白为原料通过酶解法生产一种高效、低毒的天然米糟抗氧化肽。实验结果表明:7种蛋白酶中,中性酶为最佳酶选,其最佳酶解条件为:米糟蛋白质量浓度(S)为10g/100mL,中性酶浓度(E/S,质量分数)为8%,pH为6.0,温度为60℃,时间为30min。在该最佳酶解条件下,米糟生物肽的得率为18.50%,水解度为2.84%,DPPH.(1,2-二苯代苦味肼基自由基)清除率为90.10%。该米糟生物肽具有较强的DPPH和羟自由基清除能力,其IC50值(抗氧化活性为50%时所对应的米糟生物肽质量浓度)分别为1.136、0.169g/L,还具有较强的还原能力和Fe2+螯合能力(IC50值为2.127g/L)。由此得出,米糟蛋白是一种很好的米糟抗氧化肽生产原料,且该生物肽是一种较为理想的天然抗氧化剂产品。

Study on biological peptide preparation from rice dreg protein by enzymatic hydrolysis and its antioxidative activity

In order to high-valued utilize the rice dreg resources,a natural antioxidative peptide with high effective and low toxic properties was produced from rice dreg protein by the enzymatic hydrolysis method.The results showed that the neutral enzyme was optimum among seven protease.The optimum enzymatic hydrolysis conditions were 10g/100mL rice dreg protein concentration(S),8% neutral enzyme concentration(E/S,w/w),pH 6.0,temperature of 60℃ and time of 30min.Under the optimum condition,rice dreg biological peptide had the yield of 18.50%,degree of hydrolysis of 2.84% and DPPH· scavenging rate of 90.10%.The results also showed that rice dreg biological peptide had strong scavenging capabilities on DPPH· and hydroxyl free radicals with IC50 values of 1.136 and 0.169g/L.Moreover,the rice dreg biological peptide had strong reducing capability and chelating Fe2+ ability with IC50 value of 2.127g/L.It was concluded that rice dreg protein was a good source for producing antioxidative peptide and the rice dreg biological peptide was an ideally natural antioxidants.