Folin-Ciocalteu比色法测定树仔菜总多酚

Determination of total polyphenols in Sauropus androgynus by Folin-Ciocalteu colorimetric method

【目的】建立可测定树仔菜总多酚含量的Folin-Ciocalteu比色法,为树仔菜的综合开发利用提供参考依据。【方法】以没食子酸为标准品,考察Na2CO3溶液质量浓度、Folin-Ciocalteu试剂质量浓度、反应温度及显色时间对Folin-Ciocalteu比色法测定树仔菜总多酚含量的影响,优化其显色条件。【结果】Folin-Ciocalteu比色法测定树仔菜总多酚含量的最佳显色条件为：以40%Folin-Ciocalteu试剂为显色剂、7.5%Na2CO3溶液为缓冲液,于30℃下显色反应2.0 h,在此条件下测得树仔菜总多酚平均含量为13.50 mg/100 g。树仔菜提取液在760 nm处有稳定的最大吸收峰,没食子酸质量浓度在0-400 mg/L范围内与吸光值有良好的线性关系（R^2=0.9996）;其稳定性、精密度和重复性的相对标准偏差分别为1.53%、0.13%和1.77%,平均加标回收率为101.2%。【结论】Folin-Ciocalteu比色法具有操作简单、精密度高、稳定性和重复性好等优点,可用于树仔菜总多酚含量的测定。

【Objective】A Folin-Ciocalteu method for assaying total polyphenols in Sauropus androgynus was established to provide references for development and utilization of Sauropus androgynus. 【Method 】Gallic acid was used as a standard, and the determination conditions of Folin-Ciocalteu method including concentration of sodium carbonate solution, concentration of Folin-Ciocalteu regent, reaction temperature and time were studied to determine total polyphenols of Sauropus androgynus, and these determination conditions were optimized. 【Result 】These optimum conditions for determining total polyphenols of Sauropus androgynus were as follows： 40% Folin-Ciocalteu reagent and7.5% sodium carbonate solution at 30 ℃ for 2.0 h reaction. The total polyphenols content of Sauropus androgynus was 13.50 mg/100 g. Sauropus androgynus extracts had the highest and stable absorption peak at 760 nm and the linear range of gallic acid standard curve was 0-400 mg/L（R^2=0.9996）. Stability, precision and repetition was 1.53%,0.13% and 1.77% by RSD（relative standard deviation） respectively, and the recovery rate was 101.2%. 【Conclusion 】This method has many advantages such as convenience, high precision, stability and good repetition, hence it can be used for determining the total polyphenols of Sauropus androgynus.