Elucidating the taste profile in black tea through molecular docking and molecular sensory science

Crush-tear-curl (CTC) black tea is the largest global tea category by trade volume. This study investigated the material basis for taste differences in CTC black tea through the analysis of electronic tongue, high-performance liquid chromatography, and high-speed amino acid analyzers. Taste contributions were calculated using threshold values and dose-over-threshold calculations, then compounds were validated through recombination, addition, and omission experiments to confirm their contributions. Caffeine, glutamate (Glu), myricetin-3-galactoside (Myr-gala), hyperoside (Que-gala), kaempferol-3-O-rutinoside (Kae-rut), and theaflavin-3'-gallate (TF-3'-G) were found to significantly influence taste, with TF-3'-G being the most contributing. Interaction tests showed that caffeine enhances astringency, TF-3'-G boosts bitterness, Myr-gala intensifies caffeine's bitterness, and Glu reduces both bitterness and astringency. Notably, Myr-gala also enhances Glu's umami. Molecular docking revealed TF-3'-G's role in bitterness and both TF-3'-G and Myr-gala activating umami receptors. This research offers molecular insights into CTC black tea's taste and its potential for food additive applications in tea processing.