核桃青皮中鞣质的提取与含量测定

Study on extraction and determination of total tannin in walnut green rind

为了建立稳定的干酪素法测定核桃青皮中鞣质含量,采用正交实验及统计分析法得到最佳的提取条件:甲醇浓度为70%,料液比为1:10,提取时间为3·5h,干酪素用量0·6g,1·5%Na2CO3,显色后40min测定。结果表明:鞣质含量在4·4～22·0μg/mL范围内呈线性关系,R=0·9991,方法平均加样回收率为96·93%,RSD为1·78%(n=6),鞣质的平均含量1·76%。此法操作简单、灵敏、稳定、可靠。

To establish a stable method for determining the content of tannin in walnut green rind by casein method,the optimum extraction process conditions were obtained：adding 70% methanol,the material ratio was 1：10,extraction time was 3.5h at room temperature by orthogonal test and statistical analysis,adopting 0.6g caseins,adding 1.5% Na2CO3,and determining after 40min.The results showed that there was good relationship in the linear range from 4.4 to 22.0μg/mL（R=0.9991）.The average spike recovery was 96.93% with the RSD of 1.78%（n=6）,the average content of tannin was 1.76%.It is simple,sensitive and reproducible to determine the content of tannin in walnut green rind.