Folin-ciocalteu比色法测桑叶中多酚含量

Determination of the Total Content of Polyphenols in the Leaf of Mulbery by Folin-ciocalteu Colorimetry

采用以没食子酸为标准,研究了Folin-ciocalteu比色法测定桑叶中多酚含量的适宜条件。结果表明,桑叶提取液在Folin-ciocalteu试剂2.0 mL、20%Na2CO3溶液5.0 mL、反应温度30℃、反应时间2 h的条件下,测定其760 nm处的吸光值,多酚浓度在10.0～100.0 mg/L范围内与吸光值呈良好的线性关系;稳定性、精密度、重现性和回收率实验的相对标准偏差为0.2969%～2.502%。该法是一种简便、快速、准确测定桑叶多酚含量的可靠方法。

A quantitative method for the determination of the total content of polyphenols in the leaf of mulberry was studied by using Folin-eiocalteu colorimetry with gallic acid as standard. The results showed that the total polyphenol contents of the leaf of mulberry could be well calculated according to their colorimetric absorption at 760 nm by applying Folin-ciocalteu reagent 2.0 mL and 20% Na2CO3 5.0 mL at 30℃for 2 h, and the linear range of standard curve was 10.0- 100.0 mg/L. Stability, precision, repetition and recovery rate were in the range of 0. 2969% -2. 502% by RSD. Therefore, Folin-ciocaheu colorimetry is convenient, fast, and accurate to determine total polyphenols of the leaf of mulbery.