Introduction: Cigar stacking fermentation is a key step in tobacco aroma enhancement and miscellaneous gas reduction, which both have a great influence on increasing cigar flavor and improving industrial availability.Methods: To analyze the effect of cigar tobacco leaf (CTLs) microbial community on volatiles flavor compounds (VFCs), this study used multi-omics technology to reveal the changes in microbial community structure and VFCs of different cigar varieties during stacking fermentation, in addition to exploring the interaction mechanism of microbiome and VFCs.Results: The results showed that the dominant microbial compositions of different CTL varieties during stacking fermentation were similar, which included Staphylococcus, Corynebacterium 1, Aerococcus, and Aspergillus. These dominant microbes mainly affected the microbial community structure and characteristic microorganisms of CTLs through microbial interactions, thereby influencing the transformation of VFCs. Characteristic microorganisms of different CTLs varieties such as Trichothecium, Trichosporon, Thioalkalicoccus and Jeotgalicoccus, were found to positively correlate with characteristic VFCs like megastigmatrienone 4, pyrazine, tetramethyl-, geranyl acetone, and 2-undecanone, 6,10-dimethyl-, respectively. This in turn affected the aroma and sensory quality of the CTLs.Discussion: This study provides theoretical support for the analysis of the mechanism of microorganisms on VFCs and aroma, and development of microbial agents during cigar stacking fermentation.

Low-pressure plasma (LPP) treatment was implemented as a nonthermal technology to preserve the organoleptic and nutritional qualities of lyophilized lemon slices. Effects of LPP treatment on the basic quality and flavor characteristics of lyophilized lemon slices stored for 7d were evaluated. Fresh lyophilized lemon slices were prepared as a reference. The total titratable acids and sugars were in the range of 1.001.11mg/mL and 190.21197.37mg/mL. The total phenolic content and Vc gradually decreased during storage from 1.74 to 1.33mg/mL and 0.53 to 0.31mg/mL. LPP had minor effects on total sugars and total titrate acids but prevented the storage losses of vitamin C (Vc) and phenols. A total of 35 volatile organic compounds were identified with C10 monoterpenoids being the major compounds. C6-C9 aldehydes corresponding to a green grassy aroma gradually decreased with increasing storage time. The gallery plot confirmed the different compositions of volatile organic compounds in LPP-treated samples. LPP-treated lemon slices had a higher content of preferred aromatic substances (terpinen-4-ol, α-terpineol, α-terpinene, and limonene) with a citrus-like flavor. These results demonstrated the positive effect of LPP treatment on retaining the flavor characteristics of lemon slices.