选择由Benzie和Strain建立的铁离子还原法(ferric reducing /antioxidant power assay,FRAP)比较不同EGCG含量茶多酚的总抗氧化能力强弱以及茶多酚与其他天然抗氧化物质的协同抗氧化作用,测定结果表明EGCG在儿茶素中比例为40%~50%时抗氧化能力最强。抗氧化物质之间的协同抗氧化作用与抗氧化物质本身的抗氧化能力,抗氧化物质有效浓度的高低等因素有关。抗氧化物质之间的协同作用,在抗氧化物质本身有效浓度较低时协同作用也较低,随着有效浓度增加,协同抗氧化作用增加,达到一个峰值后,随着有效浓度的继续增加,协同作用会逐渐减弱。
The antioxidant activity of tea polyphenols (TP) and the cooperative antioxidant activity of TP and other natural antioxidants were determined by using ferric reducing /antioxidant power assay(FRAP) established by Benzie and Strain. The results showed that it showed the highest antioxidant activity when the concentration of EGCG in tea catechins was 40%~50%. The cooperative antioxidant activity of antioxidants was related to the antioxidant activity of antioxidants themselves and the effective concentration of antioxidants. A weak activity was showed when the effective concentration of antioxidants was low, and as the concentration increased, the cooperative activity was increasing until the maximum synergizing effect, and then, the synergizing effect on antioxidant activity declined.
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