Characterizing relationships among chemicals, sensory attributes and in vitro bioactivities of black tea made from an anthocyanins-enriched tea cultivar

Tea cultivar ‘Zijuan’, a mutant of Camellia sinensis var. assamica, has high content of anthocyanins in fresh leaves which makes it suitable for producing black tea with distinctive flavor and bioactivity. In the present work, the processing conditions were optimized based on sensory evaluation, the composition of volatile and non-volatile compounds and in vitro antioxidant activity and α-glucosidase inhibition of Zijuan black tea were also investigated, the relationships among them were analyzed further. 14.1 h, 34.6 °C and 2.3 h were the best condition for withering time, fermentation temperature, and fermentation time in the process of Zijuan by sensory evaluation, respectively. Benzeneacetaldehyde, followed by (E)-2-hexenal, benzaldehyde, linalool, methyl salicylate and geraniol were the main odor-contributing volatiles; glutamine (Gln) had significant relationship with taste, and those with DPPH scavenging ability and α-glucosidase inhibition were theaflavin (TFs) and theabrownine (TBs). Interestingly, weak and insignificant correlations were found between flavor and bioactivities of Zijuan black tea.