Determining the effects of tencha‐ro drying on key volatile compounds in tencha ( Camellia sinensis ) through gas chromatography–mass spectrometry

Drying is the key process through which the aroma of tencha forms. However, the effects of drying method on volatiles are unknown. We compared tencha-ro drying with regular drying. Volatiles in tencha infusions were extracted using headspace solid-phase microextraction and solvent-assisted flavor evaporation combined with gas chromatography-mass spectrometry. Partial least squares (PLS), odor activity value (OAV), and heat map analyses were performed to identify the optimal drying method for creating a seaweed-like aroma. Changes in the key volatile compounds of the samples were investigated. The tencha infusions contained 125 volatiles with nine chemical structures. According to the sensory evaluation, tencha-ro drying was the optimal method for producing high-quality tencha with an intense and consistent seaweed-like aroma. The PLS model accurately distinguished among the types of tencha. By combining OAVs with screening through multivariate statistical analysis, six volatile compounds were revealed to contribute substantially to tencha's seaweed-like aroma: 2-ethyl-3,5-dimethylpyrazine, 2-ethyl-6-methylpyrazine, 2-ethyl-5-methylpyrazine, dimethyl sulfide, β-ionone, and 2-formyl-1-methylpyrrole. The findings provide a theoretical basis and technical guidance for the processing of high-quality tencha with a strong seaweed-like aroma. PRACTICAL APPLICATION: This study demonstrated that tencha-ro drying contributes to the formation of a seaweed-like aroma in tencha and provides theoretical guidance for tea factories to use the appropriate drying methods for high-quality tencha.