青麦仁种皮膳食纤维的提取及其抗氧化活性研究

Extraction Methods and Resistance to Oxidation of Dietary Fiber from Testa of the Green Wheat Kernel

以青麦仁种皮为原料,通过测定总黄酮含量、DPPH自由基清除能力、羟自由基清除能力和还原能力,对酶-碱法、双酶法、超声辅助酶法、微波辅助酶法4种提取方法进行评价,制备高抗氧化性膳食纤维。结果表明,超声辅助酶法为青麦仁种皮高抗氧化性水溶性膳食纤维的最优提取方法,其总黄酮含量为1.486 mg/g、DPPH自由基清除能力为76.85%、羟自由基清除能力为17.96%,还原能力(吸光度)为0.312;双酶法为青麦仁种皮高抗氧化性不溶性膳食纤维的最优提取方法,其总黄酮含量2.467 mg/g、DPPH自由基清除能力为78.5%、羟自由基清除能力为59.80%、还原能力(吸光度)为0.514。

In this study,the antioxidant activity of dietary fiber prepared from the seed coat of fresh green wheat was evaluated by measuring the content of total flavonoids,DPPH free radical scavenging ability,reducing ability and hydroxyl free radical scavenging capacity. The optimal extraction methods of watersoluble dietary fiber and insoluble dietary fiber of green wheat seed-coat were determined by comparative analysis of four extraction methods of enzyme-alkali method,double enzyme method,ultrasound-assisted enzyme method and microwave assisted enzyme method. The results showed that the ultrasound-assisted enzyme method had better effect on improving the antioxidant activity of the water-soluble dietary fiber.The content of total flavonoids in soluble dietary fiber was 1. 486 mg/g. The scavenging ability of DPPH radical was 76. 85%. The scavenging ability of hydroxyl radical was 17. 96%. Reducing ability( absorbance) was 0. 312. The double enzyme method had better effect on improving the antioxidant activity of the insoluble dietary fiber. The content of total flavonoids in soluble dietary fiber was 2. 467 mg/g. The scavenging ability of DPPH radical was 78. 5%. The scavenging of hydroxyl radical was 59. 80%. Reducing ability ability( absorbance) was 0.514.