四种豆类中多酚、类黄酮含量及抗氧化活性研究

对豇豆、红小豆、绿豆和蚕豆4种豆类中游离态和结合态的多酚及类黄酮的含量进行测定，并比较了其体外抗氧化活性。数据表明，4种不同豆类的游离态多酚和结合态多酚含量范围分别为1.35～1.75 mg/g和8.63～10.11 mg/g；游离态类黄酮和结合态类黄酮含量范围分别为1.58～2.07 mg/g和3.92～5.08 mg/g；其中结合态多酚含量是游离态多酚的5倍以上，结合态类黄酮含量是游离态的2倍以上。4种豆类游离态和结合态提取物均具有良好的抗氧化活性，其中游离态提取物对DPPH自由基的清除能力明显高于结合态，而结合态对FRAP、ABTS、O2-自由基的清除能力明显高于游离态。豆类中含有丰富的酚类、类黄酮等物质，并且主要以结合态形式存在，具有较强的抗氧化活性。

Content and antioxidant activity of phenolics and flavonoids from 4 food beans

The contents and antioxidant activity of free and bound phenolics from cowpea, vigna angularis, mung bean and broad bean were researched. The results showed that the free and bound phenolic contents of beans ranged from 1.35 to 1.75 mg/g, 8.63 to 10.11 mg/g, respectively. The free and bound flavonoids contents of the beans ranged from 1.58 to 2.07 mg/g, and 3.92 to 5.08 mg/g, respectively. The bound phenolics content is 5 times of free phenolics, and bound flavonoids content is twice of free flavonoids. The bound and free extracts have significant antioxidant activity, and the free extracts on DPPH scavenging activity was more significance than that of bound extracts. But the bound extracts on FRAP, ABTS and O2- scavenging activity was more significance than that of free bound extracts. Beans are rich in phenolics and possess high antioxidant activity. The bound phenolics/flavonoids were the main existing forms of phenolics/flavonoids.