Recent findings on seasonal variation of comprehensive volatile metabolite profiles in teas

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Recently, our team published a manuscript in the Journal of Chromatography summarizing the effects extreme weather events have on tea plant physiology. Comprehensive volatile metabolite libraries were produced for teas harvested before and after the East Asian Monsoon in SW China using automated sequential, multidimensional gas chromatography/mass spectrometry (GC-GC/MS). Using this technology, we were able to identify a total of 201 spring and 196 monsoon metabolites, with 169 common and 59 seasonally unique compounds. Spectral deconvolution of GC/MS data using the metabolite libraries showed marked seasonal differences. Striking concentration differences were observed within families in as little as 5-days after the monsoon onset, with individual metabolites increasing, decreasing or remaining the same between the seasons. The analytical methods developed in this paper will be used to profile metabolites in tea over time with respect to harvest season and climate.
Questions? Please contact the corresponding author on this manuscript, Dr. Albert Robbat, Jr. (albert.robbat@tufts.edu)

Our New PLoS ONE Publication

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Our new study published in PloSOne found that the tea functional quality as determined by the key phytochemicals responsible for tea’s main health and physiological properties in humans significantly varies with extreme weather events that are becoming more frequent with climate change. Specifically, compared to an extreme spring drought, tea leaves grown during the monsoon at our study site in SW China were up to 50% higher in terms growth parameters while concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower. Concurrently, total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in tea functional quality was associated with a decrease in tea prices and income derived from tea sales. Findings validate farmer perceptions that precipitation impacts tea quality. Extrapolating findings from this study to long term climate change suggests variability for farmers and the need to tap into farmers’ knowledge of management practices to mitigate climate risks in their agro-ecosystems for sustainability of tea production.

Questions? Please contact the corresponding author on this study, Dr. Selena Ahmed: selena.ahmed@montana.edu.