茉莉花茶主要品质成分定量近红外光谱分析模型的建立

选择有代表性的112个茉莉花茶茶样为实验材料,采用近红外光谱分析技术结合化学计量学方法对茶多酚总量(TP)、游离氨基酸总量(AA)、咖啡碱(CAFF)、水浸出物(water extract)、没食子酸(GA)、没食子儿茶素(GC)、表没食子儿茶素(EGC)、儿茶素(C)、表儿茶素(EC)、表没食子儿茶素没食子酸酯(EGCG)、没食子儿茶素没食子酸酯(GCG)、表儿茶素没食子酸酯(ECG)、儿茶素没食子酸酯(CG)这13种品质成分的含量建立定量分析模型。结果显示,除CG的模型综合评价指标Q值为0.7702以外,其余的Q值为0.8～0.9。经外部检验,CAFF和GCG的真实值与预测值的相关系数R为0.7～0.8,GC、EGCG、ECG、CG为0.8～0.9,其余均达0.9以上,模型效果较好,为简便快速地测定茉莉花茶品质成分的含量提供了新思路。

Establishment of Predictive Model for Quantitative Analysis of Major Components in Jasmine Tea by Near Infrared Spectroscopy(NIRS)

Taking 112 representative jasmine tea as research material,the quantitative calibration models for determining the contents of 13 chemical compositions such as total tea polyphenols(TP),free amino acids(AA),caffeine(CAFF),water extract,GA,GC,EGC,C,EC,EGCG,GCG,ECG,CG were established by NIRS combined with chemometrics.Q-value taking all important statistical values into account can evaluate the quality of models.Results showed that almost all the Q-value of models was 0.8~0.9,except for CG with a Q-value of 0.7702.Each of the 13 predictive models was applied for external inspection.Coefficients of correlation(R) between predicted value by NIR and the actual value were exceed 0.9,except CAFF and GCG was 0.7~0.8 and GC、EGCG、ECG、CG was 0.8~0.9.The established models present high stability and predictive accuracy.This paper provided a simple and convenient method for measuring the contents of major quality components in jasmine tea.