采用近红外光谱技术定量分析绿茶中的主要呈味物质

Quantitative Analysis by NIR Spectrum Technique for the Main Components of Savor in Green Tea

以具有代表性的绿茶为试验材料,对绿茶茶汤中主要的3种呈味物质(茶多酚、氨基酸、咖啡碱)进行近红外光谱定量分析,并建立相应的校准模型。茶多酚模型定标集标准差(SEE)、相关系数(SEE-r)和验证集标准差(SEP)、相关系数(SEP)分别为1.1455、0.8792和1.0600、0.8623;氨基酸模型的SEE、SEE-r、SEP、SEP分别为0.2518、0.9728、0.2597、0.9722;咖啡碱模型的SEE、SEE-r、SEP、SEP分别为0.5553、0.9648、0.5315、0.9554。经外部验证,所测样品的化学值与模型预测值的决定系数R:茶多酚0.8935、氨基酸0.9541、咖啡碱0.9386。该模型可满足茶叶成分分析的要求,实现了茶汤主要呈味物质的快速测定。

Choosing some representative kinds of green tea as the materials, the experiment established the calibration models of three main sapor components tea polyphenols （TPP）, amino acids （AA） and theine from the tea soup by using NIR Quantitative analysis. The tea polyphenols（TPP） model： the standard error of calibration（SEE）, correlation coefficient（r）of calibration set（C-set）, standard error of cross-validation （SEP） and validation set （V-set） were： 1.1455, 0.8792,1.0600,0.8623. The AA model： its SEE, SEE-r, SEP and SEP-r were： 0.2518,0.9728,0.2597,0.9722. The theine model： its SEE, SEE-r, SEP, and SEP-r were： 0.5553,0.9648,0.5315,0.9554. It indicated that by external cross validation, correlation coefficient（R） of true content of samples and forecasted content of samples： R of TPP was 0.8935, R of AA was 0.9541, R of theine was 0.9386. The models could satisfy the analysis requirements of tea components. The proposed method was proved to be a rapid method for mensurating components of tea soup.