紫外分光光度法测定花生衣原花青素的含量及平均聚合度

Determination the Quantitative and the Average Degree of Polymerization of Proanthocyanidins in Peanut Skin Extract with Ultraviolet Spectrophotometry

目的建立紫外分光光度法测定花生衣提取物中原花青素含量及平均聚合度方法。方法采用改良香草醛法,乙酸为溶剂,测定原花青素物质的量浓度;采用香草醛法,甲醇为溶剂,测定原花青素的质量浓度,两者折算计算花生衣提取物中原花青素的平均聚合度。结果优化后测定样品中原花青素物质的量浓度的线性范围为0.025~0.126μmol/ml(R^2=0.999 8),平均加样回收率为98.81%,RSD=1.86%(n=6),原花青素A1,A2单体化合物平均聚合度测试数据与理论值基本一致。结论本测定方法简单、准确、快速,适用于花生衣提取物中原花青素含量及平均聚合度的测定。

Objective To establish a method for detecting the quantitative and the average degree of polymerization of proanthocyanidins in peanut skin extracts by UV spectrophotometry. Methods The molar concentration of proanthocyanidins can be measured by modified vanillin method in acetic acid solvent, and then the mass concentration of proanthocyanidins is determined by vanillin method in methanol solvent. By using these two reactions, the average degree of polymerization of proanthocyanidins can be determined. Results The liner range of the molar concentration scope of the optimized colorimetric conditions is 0.025 - 0.126 ~tmol/ ml. The average recovery is 98.81% and RSD is 1.86% （n = 6）. The average degree of proanthocyanidin A1 and A2 are consistant with the theoretical values. Conclusion The method is simple, accurate, rapid and reliable for determining the quantitative and the average degree of polymerization of proanthocyanidins in peanut skin extracts.