基于ORAC评价多酚类化合物抗氧化活性

采用氧自由基清除能力(ORAC)方法考察20种多酚类化合物的抗氧化活性。结果表明，该方法具有较优的线性关系(R2=0.997）；检测限(LOD）和定量限(LOQ）为0.5～3.1 μmol·L-1，精密度＜18%，准确度91%～105%。比较20种多酚类化合物抗氧化活性，对羟基苯甲酸类化合物中，鞣花酸和没食子酸具有较强的抗氧化活性；对羟基肉桂酸类以咖啡酸及其衍生物抗氧化活性最高；在类黄酮组分中，黄烷-3-醇表现出优良的抗氧化特性，黄酮醇次之。ORAC可作为评价多酚类化合物抗氧化的简便、高效的标准化检测方法。

The Evaluation of Antioxidant Activity of Polyphenol Compounds Using ORAC

The oxygen radical absorbance capacity (ORAC) method was validated, and then ORAC values of selected 20 phenolic compounds were determined. The results indicated that linearity (R2 =0.997), limit of detection and limit of quantification (0.5—3.1 μmol·L-1), precision (<18%), accuracy (91%—105%) were determined. And ellagic acid and gallic acid had strong antioxidant activity in p-hydroxy benzoic acid compounds. Caffeic acid and its derivatives had highest antioxidant activity in hydroxy cinnamic acid. In the flavonoid constituents, flavan-3-ols showed good antioxidant properties, followed by flavonol. ORAC was considered as simple, efficient detection method of standardization for evaluation of antioxidant activity of the phenolic compounds.