Sensomics-based characterization of perceptual interactions between key odorants and polyphenols in Wuzhishan black tea

This study is the first to reveal the key aroma compounds generated during Wuzhishan black tea preparation and their interactions with tea polyphenols. Volatiles in Wuzhishan black tea were characterized using acidic volatile fraction/neutral and basic volatile fraction–solvent assisted flavor evaporation combined with aroma extract dilution analysis and gas chromatography–mass spectrometry–olfactometry. A total of 79 odorants were identified in fresh tea-leaves (33), tea leaves (36), and tea infusion (36), with 36 odorants quantified using authentic chemicals and stable isotope dilution assays, and corrected for recovery coefficients. Based on sensory evaluation, the odor activity depended on perceptual interactions between the key odorants and tea polyphenols in tea infusion. The S-curve method was used to evaluate changes in olfactory threshold (OT). In a binary mixture of tea polyphenols and key odorants, the OT of hexanal, octanal, hexanol, nonanol, 2-heptanone, benzaldehyde, and 1-octen-3-ol showed a significant increase, indicating that tea polyphenols effectively interact with these key odorants. • Seventy-nine odorants were identified in fresh tea leaves, tea, and tea infusion. • Perceptual interactions between key odorants and tea polyphenols in TI was proposed. • The thresholds of seven odorants clearly increased after adding tea polyphenols.