Non-volatile metabolite and in vitro bioactivity differences in green, white, and black teas

Camellia sinensis var. assamica cultivars 'Zijuan' (ZJ, characterized by high anthocyanin content) and 'Mengku large-leaf' (LL, with high content of catechins) are widely consumed in China. Therefore, when processed into green, white, and black teas, differences in composition and biological activities should be detectable. The aim of this work was to explore these potential differences. To achieve that, in vitro bioactivity assays and metabolomics combined with correlation and ridge analyses were applied. Metabolomics revealed that the concentrations of theasinensins, anthocyanins, and amino acids in ZJ teas were higher than those in LL teas. Compared with green and white teas, black teas had higher concentrations of Amadori rearrangement products and theaflavins. Bioactivity assays showed ZJ teas had stronger bioactivity than LL teas. Catechins, procyanidins, and flavone glycosides were identified as key contributors to bioactivity differences rather than anthocyanins. These results suggested that ZJ was more suitable for making functional tea beverages.