Interactions between bacterial communities and pile temperature drive aroma quality enhancement in the pile fermentation of cigar tobacco leaf

To analyze the interaction between tobacco leaf aroma and fermentation parameters, this study investigated temperature and humidity changes, as well as the evolution of aroma profiles across five consecutive fermentation batches. Microbial community diversity and succession were also summarized. Results indicated that continuous interactions between bacterial communities and pile temperature induced periodic changes in aroma profiles. Specifically, the content of esters, aldehydes, ketones, and terpenes primarily exhibited an initial increase followed by a decrease as the pile temperature rose. The impact of each batch on different aroma profiles also varied. Microbial community analysis indicated that bacterial α-diversity index changes align with the trend of aroma profiles. The bacterial community structure at the aroma inflection points of each batch differed markedly from other pile temperatures within the same batch. Dominant bacterial genera varied obviously across batches, and distinct succession patterns with pile temperatures were observed within each batch. The correlation analysis revealed that dominant microbial genera were closely related to aroma constituents, including the bacterial genera that corresponded to the aroma inflection point. This study provides a theoretical basis for regulating characteristic aroma formation by controlling the different pile temperatures.