Analysis of Differences in Mainstream Smoke Components Among Core Parents of High-quality Flue-cured Tobacco

To investigate the differences in the aroma structural characteristics of tobacco leaves among five representative core parental varieties of high-quality flue-cured tobacco, mainstream smoke components were identified using simultaneous distillation-extraction coupled with gas chromatography/mass spectrometry (SDE-GC/MS). The results indicated that a total of 59 volatile components were identified, including 19 ketones, 4 aldehydes, 11 phenols, 3 alcohols, 5 acids, 10 heterocyclic compounds, 3 polycyclic aromatic hydrocarbons, 2 aromatic nitriles, and 2 other compounds. Cluster analysis classified the five flue-cured tobacco varieties into three groups: Honghuadajinyuan form edone group, NC82 and G28 formed a second group, and Gexin 3 and K326 formed the third group. Based on Orthogonal Partial Least Squares-Discriminant Analysis (OPLS-DA), 22 differential smoke components were screened. Among them, the content of palmitic acid in NC82 was significantly higher than that in other varieties; the contents of solanone, guaiacol, and 5-methylfurfuryl alcohol in Honghuadajinyuan were significantly higher than those in the other varieties; the content of phytone in Gexin 3 was significantly higher than that in the other varieties, while its palmitic acid content was lower; and the carvenone content in K326 was significantly lower than that in the other varieties. Furthermore, combined with Odor Activity Value (OAV) analysis, a total of 8 differential components contributing to smoke characteristics were identified. Among these, the OAV of solanone was greater than 1 only in Honghuadajinyuan, and less than 1 in other varieties. The contribution weights of the remaining 7 components were largely consistent across the varieties. Their contribution rates, in descending order, were as follows: guaiacol, furfuryl alcohol, 4-ethylphenol, acetophenone, methylcyclopentenone, benzonitrile, and 2-ethylphenol. These components might contribute significantly to distinguishing the smoke characteristics of different varieties. This study provides a theoretical basis for the aroma breeding and quality improvement of flue-cured tobacco.