Abstract: To investigate the effects of concentration and coculture treatments of functional microorganisms on the aroma quality of fermented cigar tobacco leaves (CTLs), CTLs from Nanping, Fujian Province were used as raw materials. Fermentation was conducted with different Saccharomyces cerevisiae Y1 (Sc) inoculation concentrations [10⁶ CFU/g (E6), 10⁷ CFU/g (E7), and 10⁸ CFU/g (E8)] and functional microorganisms [Sc, Pichia spp. (Pi), Metschnikowia pulcherrima (Mp), Torulaspora delbrueckii Y7 (Td）] coculture patterns (Sc+Pi, Sc+Mp, and Sc+Td). The types and contents of aroma constituents in the treated CTLs were analyzed by HS-SPME-GC-MS. The results showed that the microbial concentration had a significant dose-dependent effect on the aroma constituents in CTLs. In the E6 and E8 treatments, the contents of alcohols, acids, aldehydes, and nitrogen heterocycles in CTLs were significantly higher than those in the control, and the contents of esters, ketones, and terpenes in the E8 treatment were also significantly higher. The effects of coculture treatments on aroma constituents exhibited strain-specificity. The Sc+Pi and Sc+Mp treatments significantly increased the contents of total aroma constituents, alcohols, ketones, and terpenes, with total aroma constituents increasing by 20.89% and 26.10%, respectively, compared to the control. PLS-DA further revealed obvious differences in the aroma profiles among different functional microbial concentrations and coculture treatments of fermented CTLs.

Key words: cigar tobacco leaves, fermentation, aroma, functional microorganisms, HS-SPME-GC-MS, PLS-DA