# Metabolite Analysis of Hangzhou Gongmei White Tea of Different Varieties
## 3 Results and Discussion
### Analysis of Major Chemical Components  
The content of major chemical components in the tea samples and the concentration in the tea infusions were measured and analysed. As demonstrated in Figures 2 and S1, the disparities between the varieties were substantial. The ranges of free amino acids, tea polyphenols, water extract, caffeine, and catechins in the tea samples were 4.70-6.08%,  
Figure 1: The sensory qualities of HGW. (**a**) The photos of tea samples, infusions, and brewed tea leaves. (**b**) Evaluation of each quality factor and calculation of the total score.  
14.37-19.24%, 43.96-48.53%, 3.69-4.66%, and 8.38-13.56%, respectively. The most significant difference was in the catechin content, which was 1.62 times higher in YS than in JM1. The content of water extract, tea polyphenols, and caffeine in JK was the highest, and the content of amino acids was moderate, rendering it rich in nutrients. Conversely, the lowest concentrations of water extract, caffeine, and free amino acids were observed in LJ. JM1 had the highest content of free amino acids, the lowest content of tea polyphenols, and the lowest ratio of polyphenols to amino acids (PAR). The content of simple catechins such as GC, EGC, and EC was lowest in LJ, and the content of complex catechins such as EGCG and GCG was also relatively low. Conversely, YS exhibited the highest concentrations of various catechins, including GC, EGC, EGCG, and GCG. The parents of YS are FD and the Yunnan large-leaf variety. Consequently, it can be hypothesised that YS has inherited the varietal characteristics of the Yunnan large-leaf variety, which has been shown to contain higher levels of polyphenolic substances [9; 11]. Conversely, BY1, JM1, LJ, and LJ43 exhibited varying degrees of leaf redness and reduced catechin levels, attributable to oxidation.  
The concentrations of various chemical constituents in the infusions were not entirely consistent with those found in the dry tea. LJ43 was characterised by thin buds and leaves, and the highest concentrations of water extract, free amino acids, tea polyphenols, and caffeine were observed in the tea infusion, resulting in the strongest flavour and deepest infusion colour. In contrast, the buds and leaves of JK were comparatively thick. While the dry tea contained high levels of tea polyphenols and water extracts, these concentrations were lower in the infusion. There was no astringency in the tea infusion. The FD infusion  
Figure 2: The content of main chemical compositions. Different lowercase letters indicate significant differences at \(p<0.05\). TP/FAA, the ratio of tea polyphenols to free amino acid; GC, gallocatedchin; EGC, epigallocatechin; C, catechin; EC, epicatechin; EGCG, epigallocatechin gallate; GCG, gallocatedchin gallate; ECG, epicatechin gallate.  
exhibited the lowest concentrations of water extract, free amino acids, and caffeine. Despite the highest PAR, the infusion colour was the lightest and the taste was sweet and thin. YS and LJ43 demonstrated significantly higher concentrations of tea polyphenols, complex catechins, and total catechins compared to the other teas. It is noteworthy that complex catechins, due to their nature, are known to elicit a bitter and stringent taste [11; 23], thus contributing to the perception of a slight astringency in the tea. It is evident that the concentration of chemical constituents in tea infusions of intact buds and leaves is not only related to the content of constituents in dry tea, but is also influenced by other factors such as leaf size and thickness. The smaller the leaves, the greater the specific surface area, which is more conducive to the dissolution of internal substances. The thicker the leaves, the slower the rate of dissolution of internal substances.