Integrated volatilomic profiles and chemometrics provide new insights into the aroma differences of volatile compounds in filler tobacco leaves of six grades

As an economically important crop, the quality grade of filler tobacco leaves (FTLs) is a key factor determining their commercial value. To investigate the sources and variations in aroma among different quality grades of filler tobacco leaves (DGFTLs), the volatile components of six DGFTLs were studied using chemometric methods. The results showed that the aroma of high-quality grade FTL exhibited a more balanced aroma profile, while the low-quality grade FTLs displayed a more pronounced pungent odor. The electronic nose (E-nose) analysis using W5S, W1S, W1W, and W2S sensors effectively distinguished the aroma variations of DGFTLs. Notably, 59 common volatile organic compounds (VOCs) were detected across all samples, with (S)-(-)-nicotine, neophytadiene, and aldehydes/ketones being the dominant VOCs in cigar tobacco leaves. By constructing a weighted correlation network model (WCNA), four positively correlated modules and eleven hub VOCs were identified in all FTL varieties. Further multi-stage variable selection revealed that benzeneacetaldehyde, sclareol, farnesylacetone, and 4-methylene-3,5,5-trimethyl-2-cyclohexen-1-one were characteristic markers contributing to the aroma differentiation among the six DGFTLs.