Comparative study on composition and pyrolytic behavior of tobacco extracts from solvent extraction and pyrolysis

This study systematically compared tobacco extracts prepared by solvent extraction and by pyrolysis in terms of their chemical composition, thermal stability, and pyrolysis product distribution. An innovative, systematic validation framework integrating residue pyrolysis and extract re-pyrolysis was employed to directly discriminate between extraction-induced compositional effects and pyrolysis-condition effects. This framework elucidates intrinsic correlations among extraction methods, chemical composition, and thermal behavior from the perspectives of aroma diversity and phenolic suppression. The results revealed that the extraction yield increased from 7.08 % to 33.48 % with increasing solvent polarity, while pyrolysis achieved an even higher yield (36.80 %) through high-temperature pyrolytic conversion. Solvent extracts exhibited polarity-driven compositional differences, whereas pyrolysis-derived extract (Py-Ext) was enriched in characteristic aroma compounds such as furfuryl alcohol and maltol, and contained more target compounds (19 types) than solvent extracts (9–15 types). Thermal analysis revealed that the solvent extracts decomposed primarily within the 135–279 ℃ range, yielding product distributions that were highly sensitive to pyrolysis conditions. In contrast, Py-Ext exhibited volatility-dominated thermal behavior that resulted in stable product distributions across a broad operational range. Extract re-pyrolysis revealed that the compositional incompleteness of solvent extracts prevents them from achieving the aromatic richness of Py-Ext, even under identical pyrolysis conditions, while residue pyrolysis confirmed that key aroma precursors were retained in the solid phase during extraction. Meanwhile, solvent extraction markedly suppressed phenolic formation during re-pyrolysis through precursor removal at the source. Overall, the proposed validation framework establishes a causal method–composition–behavior relationship, providing a basis for the rational design of tobacco extracts for targeted applications.