荧光素钠-Mn^(2+)-H_2O_2体系荧光法测定常见水果的抗氧化活性

Determination of Antioxidant Activity in Several Kinds of Fruit by Fluorimetry with Fluorescein Sodium-Mn^(2+)-H_(2)O_(2) System

荧光素钠本身能产生特征荧光,其激发波长和发射波长分别为491nm和512nm。在碱性介质中,Mn2+ H2O2体系产生的羟自由基可以迅速氧化荧光素钠使荧光猝灭,而水果提取物可以部分清除溶液中的羟自由基,从而使其荧光猝灭程度减弱。据此建立了一种测定水果抗氧化性的新方法。测试了9种常见水果的抗氧化活性,其中桃、橙子、香瓜、香蕉、西红柿的抗氧化性较强。

Fluorescein sodium can produce its characteristic fluorescence with its excitation and emission wavelength at 491nm and 512nm , respectively. Fluorescein sodium is oxidized by hydroxyl radical rapidly and fluorescence is quenching. Extractives of fruits may eliminate hydroxyl radical in solution. Then, quenching level of fluorescence of solution will be lowered. Based on this principle, a new method is developed to determined eliminating ratio of fruit for hydroxyl radical. The antioxidative activity of 9 kinds of fruits is determined. The results show that the antioxidative activity of orange skin is the strongest, followed by peach, orange, muskmelon, banana and tomato.