基于稀土元素指纹分析判别普洱古树茶和台地茶的研究

Application of Heavy Rare Earth Element Fingerprints in Discrimination of Pu 'er Old Plant Tea and Tableland Tea

摘要:

普洱茶根据不同来源分为古树茶和台地茶。古树茶被认为是一种有别于台地茶的茶，具有特殊的香气和品质。本研究为探讨基于稀土元素指纹对普洱茶不同来源判别的有效性，找寻表征判别特性的元素指标，采用电感耦合等离子体发射光谱法（ICP-MS）测定云南省西双版纳州代表性普洱茶古树茶和台地茶中的15种稀土元素（La、Ce、Pr、Nd、Sm、Eu、Gd、Tb、Dy、Y、Er、Tm、Yb、Lu和Sc）含量，对数据进行方差分析、主成分分析和判别分析，筛选出4个有效判别指标La、Ce、Eu和Sc，分别建立普洱茶古树茶和台地茶的判别模型，产地检验判别率为94.4%，交叉检验判别率83.3%；身份判别检验率为100%，交叉检验判别率91.65%。利用不同来源的普洱茶稀土含量差异，结合稀土元素指纹技术判别普洱古树茶和台地茶的分类方法是可行性的

Abstract:

Pu 'er teas are divided into old plant tea and tableland tea according to their origins. Old plant tea has a unique aroma and quality distinctive from tableland tea. The preliminary investigation was carried out to examine the feasibility of rare earth elements in identifying old plant tea and tableland tea. The samples of the two kinds of teas were selected from Xishuangbanna state of Yunan province, and the contents of 15 rare earth elements (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Y, Er, Tm, Yb, Lu and Sc) from these Pu 'er teas were determined by inductively coupled plasma mass spectrometry (ICP-MS). The analysis of variance (ANOVA), principal component analysis (PCA) and discriminant analysis (DA) showed that the discrimination models were established by four key variables (La, Ce, Eu and Sc), in which 100% classification validation for both teas and 88.9% cross validation for plant tea and 94.4% for tableland tea. It is feasible to classification of old plant tea and tableland tea by using pattern recognition technique combining with heavy rare-earth element fingerprints .