Insight into the pigmented anthocyanins and the major potential co-pigmented flavonoids in purple-coloured leaf teas

Tea cultivars possessing purple shoots have attracted global interest. In order to gain a better understanding of the major chemical constituents responsible for the purple colouration, we applied widely targeted metabolomics to investigate the pigmented flavonoids of freeze-dried purple-coloured tea leaves (PTLs) in comparison with green-coloured tea leaves (GTLs). Thirty-three anthocyanins were identified, and delphinidin 3-O-galactoside and cyanidin 3-O-galactoside were found to be the most abundant in PTLs. A total of 226 metabolites including 193 flavonoids and 33 tannins were identified, and the methylated, acylated, and glycosylated flavonoids differed significantly between PTLs and GTLs. Moreover, significant differences (p 0.01) in the average anthocyanin, flavonoid, chlorophyll and catechin contents were also observed. Four PTLs were found to contain high levels of (-)-epigallocatechin-3-(3 ''-O-methyl) gallate ( 10 mg/g). These results suggest that structurally modified anthocyanins and major potential co-pigmented flavonoids are the chemicals primarily responsible for the purple colouration of the tea leaves.

Automated summary

Tea cultivars with purple shoots have drawn global attention. A study comparing purple-coloured tea leaves with green-coloured tea leaves found differences in anthocyanins, flavonoids, and other compounds, with the former containing higher levels of certain compounds. This suggests that modified anthocyanins and co-pigmented flavonoids are primarily responsible for the purple colouration of the tea leaves.