Comprehensive Characterization of Aroma Compounds in Four Different Varieties of Cigar Tobacco Leaves from China...

In order to conduct in-depth research on the stylistic characteristics of different varieties of cigar tobacco leaves (CTLs), we have carried out the following research work: first, the Soxhlet extraction method was utilized for the pretreatment of 4 different varieties of CTLs currently available in China. Then, the two-dimensional (2D) gas chromatography-time-of-flight mass spectrometry (GC × GC-TOF-MS) technology was applied for the nontargeted flavoromics analysis of CTLs. A total of 2117 volatile compounds were identified in the extracts of the 4 CTLs varieties, encompassing alcohols, aldehydes, ketones, carboxylic acids, and their derivatives, esters, hydrocarbons, alkenes, heterocyclic compounds, and aromatics. Results from multivariate statistical analyses (principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA)) revealed significant differences in the volatile compound profiles among different CTL varieties. Based on the relative odor activity value (ROAV) analysis, key flavor compounds were determined for each variety, contributing to the unique aroma profiles of the cigars. Overall, the 4 CTLs shared similar flavor profiles, characterized by sweetness, fruitiness, greenness, nuttiness, and floral notes, with BX1 and DX2 particularly standing out in sweetness and BX1 additionally prominent in fruitiness. HY101, however, was relatively lacking in these flavor attributes compared to the other 3 varieties. Nine key differential compounds-1-butanol, 3-methyl; 1-hexanol; benzeneacetaldehyde; naphthalene; benzaldehyde; isophorone; 2-heptanone, furan, 2-pentyl; and pyrazine, trimethyl, and trimethylpyrazine-were identified as the characteristic markers among different CTL varieties. We believe that this study will not only provide important value for the analysis of flavor characteristics and variety identification of cigar tobacco leaves but also offer scientific basis for improving the quality and market advantages of cigar tobacco leaves.