Mechanisms of sweetness enhancement by sweet aroma compounds in black tea: More than just cross-modal interactions.

Black tea contains sweet aroma compounds (SACs) with sweetening potential. However, a systematic understanding of their composition, enhancing effects, and underlying mechanisms is lacking. This study identified 14 key SACs in global sweet-aroma black teas using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. Electronic tongue and sensory validation confirmed their sweetness-enhancing effects in a sugar-free black tea beverage and revealed their inherent taste properties (sweetness, astringency, pungency, and cooling). Molecular docking and dynamics simulation elucidated the stable bindings of T1R2/T1R3-benzeneacetaldehyde/β-damascenone, α-amylase-benzeneacetaldehyde, TRPV1-geraniol, and TRPM8-methyl salicylate, mediated by hydrogen bonding and hydrophobic interactions. These protein-ligand complexes were proposed to modulate sweetness, sweet aftertaste, heat-evoked sweetness, and cooling-enhanced sweetness, respectively. Consequently, this study demonstrates that SACs enhance sweetness through cross-modal interactions and inherent taste properties, providing novel mechanistic insights and actionable strategies for flavor optimization in tea beverages and other food products.