Sensomics-Guided Characterization of Liulin Baijiu and Its Empty Cup Volatilome: Uncovering the Key Odorants Behind Persistence

Liulin Baijiu (LLB), a representative Feng-flavor Baijiu, is highly regarded for its distinctive aroma and empty cup aroma; yet its chemical underpinnings remain unclear. This study employed an intergraded sensomics strategy encompassing sensory evaluation, GC-MS, GC-O-MS, AEDA, OAV, aroma recombination and omission tests. Repeated serial headspace solid-phase microextraction was applied to enhance the enrichment of trace low-volatility odorants remaining in the cup after ethanol volatilization. Nine key odorants were confirmed from 52 aroma-active compounds unveiled in LLB. Twenty-eight aroma-active compounds were identified in the 30-min empty cup sample, with six compounds achieving the highest flavor dilution (FD) factor of 729, including ethyl hexanoate, phenethyl acetate, hexanoic acid, ethyl laurate, phenol, and p-cresol, which contributed fruity, floral, fatty, and phenolic notes to the empty cup aroma. Collectively, these findings provide a molecular-scale perspective on its dynamic sensory evolution during cup-emptying process and may facilitate quality control and aroma-oriented product development.