Metabolite profiling of Camellia sinensis by automated sequential, multidimensional gas chromatography/mass spectrometry reveals strong monsoon effects on tea constituents

Seasonal variation in tea (Camellia sinensis (L.) Kuntze; Theaceae) chemistry was investigated using automated sequential, multidimensional gas chromatography/mass spectrometry (GC–GC/MS). Metabolite libraries were produced for teas harvested from the Bulang Mountains in Yunnan, China before and after the onset of the East Asian Monsoon. A total of 201 spring and 196 monsoon metabolites were identified, with 169 common and 59 seasonally unique compounds. An additional 163 metabolites were detected but their identity could not be confirmed. Spectral deconvolution of GC/MS data was used to measure the relative concentrations in the teas. Within each family individual metabolite concentrations increased, decreased and stayed the same. The major constituents in both teas were linalool (28%), geraniol (13%), α-terpineol (10%), hotrienol (4%) and nerol (3%). This work provides the foundation to monitor seasonal variations of tea chemistry.