Simultaneous Determination of Seven Bioactive Components in Oolong Tea Camellia sinensis: Quality Control by Chemical Composition and HPLC Fingerprints

A simple and reliable method of high-performance liquid chromatography (HPLC) was developed for the quality control of oolong tea (the dry leaves of Camellia sinensis): the quality control included the HPLC fingerprint and the quantitative determination of seven bioactive compounds chemicals, namely, (−)-gallocatechin, (−)-epigallocatechin, (−)-epigallocatechin gallate, caffeine, (−)-epicatechin, gallocatechin gallate, and (−)-epicatechin gallate. The developed analyses of the chemicals excelled in quantifying the chemicals in oolong tea. The chemical fingerprint of oolong tea was established using the raw materials of three main production sites in China, that is, Fujian (southern and northern parts), Taiwan, and Guangdong. The fingerprints from different cultivated sources were analyzed by hierarchical cluster analysis, similarity analysis, principal component analysis (PCA), analysis of variance (ANOVA), and discriminant analysis. The results indicated that the combination of chromatographic fingerprint and quantification analysEs could be used for the quality assessment of oolong tea and its derived products.