Folin-Ciocalteu比色法测定黑莓多酚的含量

Determination of Polyphenol in Blackberry by Folin-Ciocalteu Colorimetry

采用Folin-Ciocalteu法测定黑莓提取液中总多酚含量,确定以没食子酸为标准的最佳测定条件。结果表明:在5 mL的反应体系中,吸取0.5 mL样品,先加入2.5 mL 0.1 mol/L Folin-Ciocaltou试剂振荡后,再加入2 mL 7.5%Na2CO3溶液,摇匀,25℃显色120 min,在765 nm波长下测定吸光度,没食子酸浓度在5 mg/L^60 mg/L范围内与吸光度存在较好的线性关系。此方法操作简单、稳定性及结果重现性好。利用Folin-Ciocalteu法测定黑莓样品液中没食子酸的平均添加回收率达到100.2%,RSD为1.40%。

The total polyphenol（TP） content of blackberry was analyzed by Folin-Ciocalteu colorimetry.Using gallic acid as standard,the optimum conditions were achieved.The results showed that when 2.5 mL 0.1 moL/L Folin-Ciocalteu and 2 mL 7.5 % sodium carbonate solution were added to the 0.5 mL sample reacting 120 min in 25 ℃,there was a good linearity relationship between absorption value and Gallic acid with the concentration in 5 mg/L-60 mg/L in 765 nm.The method was simple,accurate with stable and repeated results.It can be suggested as an appropriate method to measure the TP content in blackberry.Under this method,average recovery rate of gallic acid in blackberry sample is 100.2 %.Relative standard deviation of the method is 1.40 %.