关键词: 绿茶, 微量元素, 多元统计, 产地溯源

Abstract: The contents of 31 trace elements of 42 green tea samples from four producing tea regions of Tongren City in Guizhou Province, were determined by inductively coupled plasma mass spectrometry. Correlation analysis was used to analyze the relationship between trace elements. Principal components analysis (PCA), stepwise linear discriminant analysis (S-LDA) and orthogonal partial least squares discriminant analysis (OPLS-DA) were used to analyze the trace elements of green tea in different regions. The results indicated that Co, Mo, Ag, Cd, Zn, Al, Y, Nd, Sc, Pr, Gd, Sm, Dy, Er, Yb, Ho, Tb, Tm and Lu elements in tea samples between different producing areas have significant regional differences (p＜0.05). In the process of tea tree enrichment, there was a synergistic or antagonistic relationship between some elements. The OPLS-DA had better result and the correct discrimination rate was 92.86%. This study revealed that a multivariate statistical classification model based on the content of trace elements can effectively distinguish tea samples from different regions of neighboring production areas. The method we provided can be great benefits to the traceability and safety of tea quality in the tea industry.

Key words: green tea, trace elements, multivariate statistics, origin traceability