Insight into aroma dynamic changes during the whole manufacturing process of smoked Lapsang Souchong tea

Abstract

Smoked Lapsang Souchong tea (SLST) is a distinctive black tea known for its smokey, fruity, and pine flavor. This study analyzed the aroma dynamic changes during the whole manufacturing process of SLST utilizing E-nose, HS-SPME-GC–MS, and HS-SPME-GC-O-MS. Fresh tea leaves primarily contain green and floral volatiles, such as (E)-2-hexenal (OAV 33.41) and linalool (OAV 313.88). Withering and drying processes introduce pinewood smoke-derived phenolic and terpenoid compounds, such as guaiacols (OAV 77.05) and α-terpineol (OAV 1.08), crucial for the tea's smoky and woody aroma. The study further highlights glycoside hydrolysis and lipid oxidation pathways in generating key tea-derived volatiles during fermentation, contributing to the fruity and floral notes in SLST. Pinewood smoke was identified as a major source of smoky volatiles, with longifolene and α-terpineol being unique to pinewood. These findings elucidate the formation pathways of the key volatile compounds and the impact of traditional processing on SLST's aroma profile.