近红外光谱结合化学计量法分析茶叶与茶汤的化学品质差异

Analysis of Chemical Quality Difference between Tea Leaves and Tea Beverage Using Near Infrared Spectroscopy Combined with Chemometrics

目的该研究关注中国人群偏爱的开水冲泡的饮茶方式,以评价茶汤化学品质为目的。方法采用近红外光谱法对样品进行聚类分析,构建样品的定量模型。结果泡茶的过程不能将干茶叶内容物完全溶出,且不同茶叶品种的溶解特性也存在差异。茶多酚、茶多糖和可溶性糖的综合浸出率以安吉白茶为最高;主要儿茶素和生物碱的浸出率是祁门红茶最高;茶汤中氨基酸含量在非发酵茶中显著高于发酵茶。结论我们对茶叶/茶汤样品的分类及其定量分析,为茶叶分类及其化学品质分析提供了一种快捷、简便、无损的检测方法。

Objective The purpose of this study was to evaluate the chemical quality of tea beverage by focusing on the preferred drinking method of boiled water.Methods Near infrared spectroscopy was used to cluster and establish a quantitative model for the tea leaves and tea beverage samples.Results The dry tea contents cannot be completely dissolved in the tea brewing process,and there were differences in the dissolution characteristics of different tea varieties.The results showed that the comprehensive extraction rate of tea polyphenols,tea polysaccharides and soluble sugars was the highest in white tea.The leaching rate of main catechins and alkaloids was the highest in black tea.Amino acid content in non-fermented tea beverage was significantly higher than that in fermented tea beverage.Conclusion Our analysis provides a fast,simple and non-destructive method for tea classification and chemical quality analysis.