The impact of the unique two-stage bunch-drying on the formation of the floral aroma of Niangniang tea

Niangniang tea is typically processed using a two-stage bunch-drying process, which gives it distinct floral aroma characteristics. This study investigated the impact of the two-stage bunch-drying process on the formation of Niangniang tea's floral aroma and compared it with green tea and yellow tea. Sensory evaluation, metabolomics, aroma recombination and omission tests, and molecular docking results revealed that Niangniang tea's key aroma compounds were linalool, hotrienol, <i>p</i>-anisaldehyde, 5-nonanone, <i>S</i>-methyl thiohexanoate, 1-nonen-3-ol, and 2-isopropyl-3-methoxypyrazine. <i>p</i>-Anisaldehyde, linalool, and hotrienol were responsible for Niangniang tea's intense floral aroma, and <i>p</i>-anisaldehyde was the marker of the floral aroma of NNT. This study identified the key floral compounds in Niangniang tea and revealed how the two-stage bunch-drying process influenced aroma formation. These results provide a theoretical basis for optimizing the bunch-drying process parameters in future studies.