Tea aroma formation from six model manufacturing processes.

Tea aroma is determined by the nature of the plant, the production processes, and many other factors influencing its formation and release. The objective of this study was to investigate the impact of manufacturing processes on the aroma composition of tea. Fresh tea leaves from the same cultivar and growing area were selected for producing the six types of tea: green, white, yellow, oolong, black, and dark teas. Comprehensive analysis by gas chromatography mass spectrometry (GC/MS) was performed for the volatiles of tea infusion, prepared by solid-phase microextraction (SPME), solid-phase extraction (SPE), and solvent assisted flavor evaporation (SAFE). A total of 168 volatile compounds were identified. Black tea has the highest volatile concentration of 710 µg/g, while green tea has the lowest concentration of 20 µg/g. Significantly affected by these processes, tea aroma molecules are formed mainly from four precursor groups: carotenoids, fatty acids, glycosides, and amino acids/sugars.