不同产区龙井茶相似性及线性判别

Similarity and Linear Analysis of Longjing Tea from Different Production Areas

对来自西湖龙井一级保护区、西湖龙井二级保护区、钱塘产区、越州产区4个产区的527份龙井茶样品进行了高效液相色谱测定和主成分分析及线性判别,结果表明:不同产区的龙井茶在儿茶素等酚性物质及咖啡碱含量上没有显著性差异;通过主成分分析,提炼出5个主成分,其中第一主成分构成中影响较大的因子有EGCG、EGC、C、CAF和EC,第二主成分构成中影响最大的因子为ECG;在第一第二主成分得分值平面中,样品点基本按照品种聚合成群,说明原料品种不同是影响龙井茶的内含成分的主要因素之一;欧氏距离与判别分析结果显示,二级保护区的西湖龙井茶与一级保护区西湖龙井茶之间的差异最大,越州龙井与一级保护区西湖龙井茶产品间差异较小。

In present study, totally 527 Longjing tea samples were collected from four production areas and analyzed by high performance liquid chromatography （HPLC）, combined with principal component analysis（PCA） and linear discriminant analysis（LDA）. The result showed that 5 PCs could be extracted and the most important factors in the first PC composition were EGCG, EGC, C, CAF and EC. Meanwhile, the most important factor in the second PC was ECG. And in the score plot of the first two PCs, samples grouped according to the varieties of their fresh leaf material. On the other hand, the result of discriminant and Euclidean distance analysis suggested that the tea samples of Xihu Longjing secondary protection zone had the least similarity to those of primary protection zone. And compared to other two groups, the difference between Yuezhou Longjing and Xihu Longjing primary protection zone was the least.