Volatile Profile and Aroma Development in Steamed Green Tea Flakes Using the Tencha Processing Procedure

This study investigated volatile changes during the industrial-scale production of steamed green tea flakes ( Camellia sinensis from Meitan, Guizhou, China) using the Tencha processing procedure. Using headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS), odor activity value (OAV) analysis, quantitative descriptive analysis (QDA) and aroma recombination/omission assays, we identified 247 volatile compounds, with 26 key odorants significantly shaping the aroma. Among them, ( E )-6-nonenal (nutty), phenethyl isovalerate (floral), and thiophene-2-methanethiol (roasted) exhibited the highest aroma contributions. Steam fixation induced a marked loss (84.79%) in volatiles, while secondary oven drying enhanced the formation of terpenoids, esters, and aldehydes. Terpenoids and aldehydes were predominantly associated with floral, fresh, and woody notes via the terpenoid, and lipid oxidation pathways; esters imparted fruity and sweet nuances; and heterocyclic Maillard byproducts conferred roasted characteristics. These findings offer a basis for optimizing industrial processing to enhance the quality and utility of tea flakes in food applications.