Mechanism and dynamic evolution of LED irradiation on volatile metabolites: A novel strategy for optimizing aroma...

Innovative Black Tea (IBT) is a novel black tea characterized by fruity and floral flavours, developed using aroma-enriched cultivars and a shaking-integrated withering process. In this study, a novel LED combination lighting system (red + blue + yellow + white) was used to improve tea aroma. Integrated metabolomic and molecular sensory analyzes revealed that LED treatment significantly promoted floral, fruity, and sweet notes while reducing green and fatty odours. This effect was attributed to key differential odorants including linalool (odour activity values (OAV): 85.3, 53.95), geraniol (56.06, 38.67), damascenone (12.2, 7.12), methyl salicylate (3.17, 1.96), nonanal (9.96, 12.33) and (E,E)-2,4-heptadienal (2.24, 2.55), derived from methylerythritol phosphate metabolism, shikimate metabolism, fatty acid oxidation, carotenoid oxidation and glycoside hydrolysis. Molecular docking simulations revealed that these odorants exhibited spontaneous binding affinity with human olfactory receptors OR1A1 and OR1A2, with binding energies below -5 kcal/mol, primarily mediated through hydrogen bonding and hydrophobic interactions.