Characterisation of the Aroma‐Active Compounds of Essential Oil of Kezixiang by Different Extraction Processes Using GC × GC–TOF–MS and GC–O–MS

Kezixiang agarwood essential oil is the luxury aromatic product widely used in high‐end perfumery. Aroma quality, as one of the most critical determinants of Kezixiang agarwood essential oil, exhibits significant variations depending on extraction methods, though these differences remain poorly characterised. This study employed comprehensive analytical strategies using GC × GC–TOF–MS and GC–O–MS to elucidate the aroma profiles of Kezixiang agarwood essential oil obtained through steam distillation (SDAO) and supercritical carbon dioxide extraction (SCAO). GC × GC–TOF–MS analysis identified 240 volatile compounds, predominantly sesquiterpenes and their oxygenated derivatives. GC–O–MS detected 58 aroma‐active compounds (54 in SDAO, 32 in SCAO), contributing to 11 sensory attributes: woody, cool, herbal, bitter, spicy, sweet, sour, floral, fruity, creamy and fatty notes. Their flavour dilution (FD) factors ranged from 3 to 19,683. Eighteen compounds exhibited FD factors ≥ 27, with benzylacetone, aromadendrene epoxide, coumarin, (E)‐2‐nonenal, nonanol, 9‐cedranone, anisicaldehyde and eudesma‐3,11‐dien‐2‐one demonstrating FD factors exceeding 100. Notably, SDAO displayed higher FD values than SCAO in most cases. SDAO exhibited an intense woody aroma with pronounced herbal and bitter notes, whereas SCAO presented a milder profile dominated by creamy and sweet nuances. These distinct sensory characteristics were strongly correlated with the type and content of the key odorants. This study provides the molecular‐level characterisation of aroma differentiation between SDAO and SCAO, establishing a scientific foundation for targeted optimisation of agarwood essential oil production.