Molecular and gustatory characterisation of the impact taste compounds in black tea infusions

Bioresponse-guided fractionation of black tea infusions, identification of intense taste compounds by LC-MS/MS and 1D/2D-NMR spectroscopy and quantitative analysis were followed by calculation of dose-over-threshold values and biomimetic taste reconstruction. The analyses revealed that besides epigallocatechingallate, catechin, and caffeine a series of flavon-3-ol glycopyranosides are key contributors to black tea taste. Neither the high molecular thearubigens, nor the theaflavins were important tastants. Recordings of human dose-response functions in model systems demonstrated that the flavanol-3-glycosides do not only impart a velvety astringent taste sensation, but do also show a major contribution to the bitter taste by amplifying the bitterness of caffeine.