Study on the correlation between the dominant microflora and the main flavor substances in the fermentation process of cigar tobacco leaves

Xue Wu; Yanqi Hu; Qian Wang; Jian Liu; Song Fang; Dewen Huang; Xueli Pang; Jianmin Cao; Yumeng Gao; Yang Ning

doi:10.3389/fmicb.2023.1267447

Study on the correlation between the dominant microflora and the main flavor substances in the fermentation process of cigar tobacco leaves

Front Microbiol. 2023 Nov 21:14:1267447. doi: 10.3389/fmicb.2023.1267447. eCollection 2023.

Authors

Xue Wu^{1

2}, Yanqi Hu³, Qian Wang¹, Jian Liu¹, Song Fang¹, Dewen Huang⁴, Xueli Pang¹, Jianmin Cao¹, Yumeng Gao^{1

2}, Yang Ning¹

Affiliations

¹ Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, China.
² Graduate School of Chinese Academy of Agricultural Sciences, Beijing, China.
³ Shandong China Tobacco Industry Limited Company, Jinan, China.
⁴ Hunan Tobacco Company Chenzhou Company, Chenzhou, China.

Abstract

The flavor of cigar tobacco leaf determines the quality of finished cigar tobacco, and the enhancement of flavor generally relies on microbial fermentation. In this paper, the correlation between the dominant microorganisms and the main flavor substances of cigar tobacco leaves during fermentation and the correlation between the two were investigated to reveal the correlation between microorganisms and flavor and the metabolic pathways of microorganisms affecting the flavor substances. During the fermentation process, the main flavors of cigar tobacco leaves were sweet, light and grassy, with hexanal, 2,6-dimethylpyridine, nonanal, phenylacetaldehyde, naphthalene, and methyl benzoate as the main constituents, and the key microorganisms Haloferax mediterranei, Haloterrigena limicola, Candidatus Thorarchaeota archaeon SMTZ-45, the genera Methyloversatilis, Sphingomonas, Thauera, Pseudomonas, Penicillium, and Aspergillus. Correlation analysis revealed that fungi were negatively correlated with the main aroma and inhibited the main flavor substances, while bacteria were positively correlated with Benzoic acid, methyl ester in the main flavor substances, which was conducive to the accumulation of green aroma. Functional analysis revealed that the dominant bacterial population was producing aroma by metabolizing glycoside hydrolases and glycosyltransferases, performing amino acid metabolism, carbohydrate metabolism and film transport metabolism. The present study showed that the bacterial and fungal dominant microorganisms during the fermentation of cigar tobacco were influencing the production and degradation of the main flavor substances through the enzyme metabolism by the occurrence of the Merad reaction.

Keywords: cigar tobacco; correlations; flavor substances; gas chromatograph/sniffer; macro-genome sequencing; relative odor activity values.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The authors would like to express their sincere thanks to the Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences ASTIP-TRIC07, Chenzhou Tobacco Company Project (GB5C2021JS02), and the Science and Technology Program of Shandong Zhongtian Tobacco Industry Limited Liability Company (202201020) for the financial support of this study. The funders were not involved in the study design, analysis, interpretation of data, the writing of this article or the decision to submit it for publication.