Formation and transfer patterns of key aroma compounds in cigar tobacco based on SBSE-GC-O-MS, pyrolysis-GC-O-MS and flue gas analysis correlation studies

The aromatic quality of cigars represents their core value, arising from the thermal transformation and migration of inherent components within tobacco leaves-a highly complex dynamic process. To systematically trace the evolution of key aroma compounds from tobacco leaves to smoke, this study pioneered a combined strategy of Stirred Barrel Sorption Extraction (SBSE), Pyrolysis (PY), and mainstream smoke capture. Utilizing Gas Chromatography-Olfactometry-Mass Spectrometry (GC-O-MS) coupled with Odor Activity Values (OAV) and correlation network analysis, a comprehensive analysis was conducted. Results revealed: The intrinsic aroma of cigar tobacco leaves is dominated by terpenes and carotenoid degradation products, presenting a "green and citrus fruit" profile. Pyrolysis fundamentally transforms the aroma spectrum into a "toasty sweetness and roasted nutty" profile centered on furan and pyrazine compounds. While smoke exhibited a balanced profile blending sweet, green, and fruity notes. Quantitative DTE revealed highly efficient nicotine transfer (30%), pyrazine pyrolysis enrichment (40%-50%), and phenol thermal generation (Thermal Generation Factor >8), with only 44% of Neophytadiene entering the smoke. Correlation analysis revealed that Phenol and 2-methoxy- in pyrolysis products positively correlated with multiple terpenes, aldehydes, and nitrogen-containing heterocyclic compounds in tobacco leaves, while Phenol showed negative correlations. The roasted aroma marker furfural in smoke significantly correlated with neophytadiene, a carotenoid degradation product in tobacco leaves. While the characteristic nutty aroma component 2,6-dimethylpyrazine showed a strong positive correlation with α-terpineol acetate in the tobacco leaf itself. This study elucidates the formation mechanism of cigar characteristic aromas at the molecular level, providing important theoretical basis for precise quality evaluation, scientific formulation design, and process optimization of cigar tobacco.