Dynamic Changes in Quality Attributes and Microbial Communities of Cigar Tobacco Leaves during Barrel Aging

Barrel aging is an effective process for enhancing cigar tobacco quality, yet the dynamic interplay between microbial communities and chemical-sensory changes remains poorly characterized. This study comprehensively investigated the mechanisms underlying quality evolution during wooden barrel aging of cigar tobacco leaves. Conventional chemical components exhibited an initial increase followed by a decrease throughout the aging process. A total of 104 volatile compounds were identified using GC-MS. Bacterial communities were profiled via 16S rRNA amplicon sequencing. Barrel aging significantly increased the complexity and sensory quality of the aroma with optimal observed at 21 d. Critically, key bacterial genera (Aerococcus, Rhizobium, Brevibacterium) showed significant positive correlations (P < 0.05) with aroma enhancement and sweetness, indicating their metabolic roles in volatile synthesis. These findings establish that barrel aging drives synergistic microbial-chemical transformations, providing the integrated evidence linking microorganism-dominated processes to aroma enrichment and sensory improvement, offering a scientific basis for precision aging protocols in cigar production.