Deciphering the Aroma-Driven Mechanism of Sweet Flavor in Keemun Black Tea

The sweetness of Keemun black tea (KBT) is a critical determinant of its overall sensory quality. This study used sensory analysis to quantitate the sweet odor and flavor of KBT. The results indicated that volatile compounds, rather than soluble sugars or free amino acids, are the main contributors to KBT's sweet flavor. Ten odorants with an odor activity value > 1 were identified by the Sensomics approach and screened by applying the odor-induced taste enhancement (OITE) method, i.e. β-damascenone, (E)-β-ionone, linalool, methional, dimethyl sulfide, geraniol, β-myrcene, coumarin, citral, and 2-phenylacetaldehyde, which were identified as the key drivers of KBT's sweet flavor. Omission and addition experiments confirmed that the intensity of sweet odor was correlated with sweet flavor (r = 0.71). These findings demonstrate that the sweet flavor of KBT mainly originates from its odorants, which synergistically enhance sweetness through OITE, resulting in the high overall flavor quality of KBT.