Black tea aroma formation during the fermentation period

The present study aimed to systematically investigate black tea aroma formation during the fermentation period. In total, 158 volatile compounds were identified. Of these, most amino acid-derived volatiles (AADVs) and carotenoid-derived volatiles (CDVs) showed significant increases, while fatty acid-derived volatiles (FADVs) and volatile terpenoids (VTs) displayed diverse changes during the fermentation period. During this time, fatty acids, amino acids, carotenoids, and glycosidically bound volatiles (GBVs, especially primeverosides) were found to degrade to form aroma components. Further, equivalent quantification of aroma showed that the intensity of green scent was notably decreased, while the intensities of sweet and floral/fruity scents were greatly increased and gradually dominated the aroma of tea leaves. AADVs and CDVs were shown to make greater contributions to the formation of sweet and floral/fruity scents than VTs. Our study provides a detailed characterization of the formation of sweet and floral/fruity aromas in black tea during the fermentation period.

Automated summary

The present study systematically investigated the formation of black tea aroma during the fermentation period. It identified 158 volatile compounds and found that most amino acid-derived volatiles (AADVs) and carotenoid-derived volatiles (CDVs) increased significantly, while fatty acid-derived volatiles (FADVs) and volatile terpenoids (VTs) displayed diverse changes. The study also revealed the degradation of fatty acids, amino acids, carotenoids, and glycosidically bound volatiles (GBVs) to form aroma components. The intensity of green scent decreased while the intensities of sweet and floral/fruity scents increased and gradually dominated the aroma of tea leaves. AADVs and CDVs were shown to contribute more to the formation of sweet and floral/fruity scents than VTs.