籼粳稻米糠多酚成分及其抗氧化性的比较研究

Comparative Study on Polyphenol Components and Antioxidant Activity of Indica and Japonica Rice Bran

以3种籼稻和3种粳稻米糠为原料,分别进行游离酚和结合酚类物质的提取,测定其多酚、总黄酮和单体酚酸含量,采用了DPPH·、ABTS+·和FRAP方法探究了提取物的体外抗氧化活性。结果表明,籼稻和粳稻米糠的多酚含量平均值分别为(2.56±0.49)、(5.10±0.85)mg GAE/g DW,总黄酮含量平均值分别为(0.38±0.24)、(1.48±0.48)mg RE/g DW,粳稻米糠多酚、总黄酮含量明显高于籼稻。游离态的单体酚酸以没食子酸和丁香酸为主,结合态单体酚酸以阿魏酸和对香豆酸为主。抗氧化能力测定结果对比分析表明:粳稻米糠抗氧化能力明显强于籼稻。

Three kinds of indica rice and three kinds of japonica rice bran were used as the raw materials to extract free phenols and bound phenols,respectively.The contents of total phenols,total flavonoids and monomeric phenolic acids were determined.DPPH·,ABTS+·and FRAP methods were used to explore the in vitro antioxidant activity of the extracts.The results indicated that the average contents of total phenols in rice bran of indica and japonica rice were(2.56±0.49),(5.10±0.85)mg GAE/g DW,respectively,and the average contents of total flavonoids were(0.38±0.24),(1.48±0.48)mg RE/g DW,respectively.The contents of total phenols and total flavonoids in rice bran of japonica rice were significantly higher than those of indica rice.The free monomer phenolic acids were mainly gallic acid and syringic acid,and the bound monomer phenolic acids were mainly ferulic acid and p-coumaric acid.The comparative analysis of antioxidant capacity showed that the antioxidant capacity of japonica rice bran was significantly stronger than that of indica rice.