基于正交偏最小二乘判别分析法分析茯砖茶和千两茶差异性品质成分

The difference of quality components of Fuzhuan tea and Qian-liang tea based on the orthogonal partial least squares discriminant analysis model

目的分析茯砖茶和千两茶品质成分的差异,为茯砖茶和千两茶品质鉴定和差异鉴别提供依据。方法以44个品质成分为指标并结合正交偏最小二乘判别分析法(orthogonal partial least squares discriminant analysis,OPLS-DA)分析,选取VIP(variable importance in projection)值大于1且具有显著差异的品质成分作为特征性差异成分。结果茯砖茶中除草酸外,其余各主要成分含量均高于千两茶。经OPLS-DA共识别出9种VIP值大于1的差异成分,其中水浸出物、茶多酚、咖啡碱、简单儿茶素和儿茶素为标志性差异品质成分。结论采用OPLS-DA分析茶叶样品品质成分,既可以对茯砖茶和千两茶进行鉴别区分,又可以筛选出两种茶类差异品质成分。

Objective To analyze the difference in the quality components of Fuzhuan tea and Qian-liang tea in order to provide basis for the identification of quality and difference of Fuzhuan tea and Qian-liang tea. Methods Forty-four quality components as indicators and combined with orthogonal partial least squares discriminant analysis（OPLS-DA） was used, the quality components of variable importance in projection（VIP） value greater than 1 and significant difference were selected as characteristic differences. Results Besides oxalic acid, the content of the other main components in Fuzhuan tea was higher than Qian-liang tea. According to the OPLS-DA consensus, there were 9 different types of VIP values greater than 1, including water extract, tea polyphenol, caffeine, simple catechins, and catechins as the signature difference of quality components. Conclusion OPLS-DA can be used to analyze the quality components of tea samples, which not only can distinguish the Fuzhuan tea and Qian-liang tea, but also can screen out the difference quality components of them.