Characterization of Key Aroma Active Compounds in Sichuan Pepper Oleoresins From Different Origins by GC-O-MS and GC×GC-TOF-MS.

The aroma profile of Sichuan pepper oleoresin (SPO), a potent flavoring agent, varies significantly with geographical origin, but key volatile organic compounds (VOCs) defining these differences are not well understood. This study aimed to delineate the volatile profiles and identify pivotal VOCs in SPOs from three distinct Chinese regions: Wudu (Gansu), Hanyuan (Sichuan), and Hancheng (Shaanxi). Headspace solid-phase microextraction coupled with comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (HS-SPME/GC×GC-TOF-MS) was employed for non-targeted analysis, identifying 168 VOCs, with terpenes as the most abundant class (45%-62%). Orthogonal projections to latent structures-discriminant analysis (OPLS-DA) revealed 25 key differential compounds (VIP > 1, p < 0.05). GC-olfactometry-MS (GC-O-MS) analysis identified 32 major aroma-active compounds, including linalyl acetate, linalool, and sabinene. Sensory evaluation and correlation analysis indicated that caryophyllene oxide, α-phellandrene, phenethyl acetate, linalool, linalyl acetate, and caryophyllene were associated with mint, turpentine, woody, floral, fruity, and spicy attributes, respectively. These findings elucidate the primary contributors to the distinct aroma profiles of SPOs from different origins, providing a basis for quality control and targeted flavor development.