Comparative Analysis of Sensory Quality and Chemical Composition between Jinhua White Tea and Fu Brick Tea

This study included four Jinhua white tea samples and five Fu brick tea samples to systematically investigate the differences in sensory quality and chemical composition between the two types of tea. Sensory evaluation results showed that compared with Fu brick tea infusion, Jinhua white tea infusion exhibited a redder color with a sweet, fruity aroma and a sweet, mild/mellow taste profile. A total of 130 compounds were identified in the tea samples using a metabolomics approach based on liquid chromatography-mass spectrometry (LC-MS), including 8 alkaloids, 9 amino acids, 13 dimeric catechins, 16 N-ethyl-2-pyrrolidinone-substituted flavan-3-ol (EPSF), 15 flavanols, 31 flavanols and flavanol-O-glycosides, 2 flavonoids, 2 lipids, 8 organic acids, 11 phenolic acids, 7 catechin B-ring cleavage derivatives, and 8 other compounds. Partial least squares-discriminant analysis (PLS-DA) and heatmap analysis revealed significant differences in chemical composition between Jinhua white tea and Fu brick tea. Among these, 78 significantly differential compounds were identified (P < 0.05). Amino acid content was generally higher in Jinhua white tea than in Fu brick tea. Jinhua white tea had lower levels of esterified catechins (epigallocatechin gallate, epicatechin gallate, gallocatechin gallate, and catechin gallate) but higher levels of non-esterified catechins (epicatechin and epigallocatechin) than Fu brick tea. The contents of catechin dimers (theaflavins, theasinesins, and procyanidins), as well as those of 4 differential catechin derivatives with B-ring cleavage, were generally higher in Jinhua white tea than in Fu brick tea. The contents of 12 EPSFs were significantly lower in Jinhua white tea than in Fu brick tea. The levels of flavanols and flavanol-O-glycosides were lower in Fu brick tea than in Jinhua white tea. The contents of caffeine and guanylate (GMP) were both significantly higher in Jinhua white tea than in Fu brick tea. This study provides a theoretical basis for clarifying the health benefits of Jinhua white tea.