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Coffee fermentation is crucial for flavor and aroma, as microorganisms degrade mucilage and produce metabolites. This study aimed to provide a basis for understanding the impact of microorganisms on Coffea arabica from Yunnan, China, during washed processing. The microbial community structure and differentially changed metabolites (DCMs) of C. arabica beans during washed processing were analyzed. The results indicated that the top five predominant microorganisms at the genera level were Achromobacter, Tatumella, Weissella, Streptococcus, and Trichocoleus for bacteria and Cystofilobasidium, Hanseniaspora, Lachancea, Wickerhamomyces, and Aspergillus for fungi. Meanwhile, the relative content of 115 DCMs in 36 h samples decreased significantly, compared to non-fermentation coffee samples (VIP > 1, p < 0.05, FC < 0.65), and the relative content of 28 DCMs increased significantly (VIP > 1, p < 0.05, FC > 1.5). Furthermore, 17 DCMs showed a strong positive correlation with microorganisms, and 5 DCMs had a strong negative correlation (p < 0.05, |r| > 0.6). Therefore, the interaction and metabolic function of microbiota play a key role in the formation of coffee flavor, and these results help in clarifying the fermentation mechanisms of C. arabica and in controlling and improving the quality of coffee flavor. [ABSTRACT FROM AUTHOR]

Wuliangye‐flavor liquor (WLFL), a specific Chinese traditional liquor, one of the major type of global distilled spirits, offers a unique flavor system acquired across thousands of years of development. Free amino acids (FAAs), as major health factors, are considered to be primarily derive from the hydrolysis of protein from the Zaopeis (ZPs) by microbial populations during fermentation. Here, we investigated the changes of microbial communities in ZPs and FAAs in raw liquor (RL) directly related ZPs from different ages of WLFL fermentation pits by phospholipid fatty acid fingerprint (PLFA) and high performance liquid chromatography method. Results indicated that the total PLFAs of 20‐ and 50‐year ZPs were significantly higher (p <.05) than 1‐ and 5‐year ZPs. Gram‐positive bacteria (G+), anaerobic bacteria, and fungi were dominant in the ZPs. Furthermore, the total of FAAs content was highly increased (p <.05) in RLs of aged fermentation pit (20‐ and 50‐year, 24.86–30.23 mg/g, 28.73–37.15 mg/g) compared with young (1‐ and 5‐year, 20.97–26.46 mg/g, 17.83–28.70 mg/g), while, the different ages of RLs could be distinguished according to 9 biomarkers of FAAs (Variable importance in projection, VIP >1; p <.05), including tyrosine, aspartic acid, leucine, glutamic acid, citrulline, alanine, proline, glycine, and valine. Particularly, the biomarkers of FAAs were positively correlated with gram‐negative bacteria (G−) and fungi, but negatively correlated with G+. This is the first report to uncover the microbial communities in zaopeis, free amino acids in RL, and their correlations for Wuliangye‐flavor raw liquor production. [ABSTRACT FROM AUTHOR]

The current study employed a combination of high-throughput sequencing and non-targeted metabolomics techniques to elucidate the changes in the quality, microbial communities, and metabolites throughout the fermentation process of traditional Midu Juanti , a traditional fermented meat product that originates from ethnic minority regions in southwestern China. The findings show that 22 dominant genera (7 bacterial and 15 fungal genera), with a relative abundance >1%, were successfully identified during the fermentation of Midu Juanti. Additionally, 979 metabolites were identified using the Human Metabolome Database (HMDB) annotation. Among these, lipids and lipid-like molecules constituted the largest proportion, followed by organic acids and their derivatives. Moreover, based on the variable importance in the projection (VIP) > 2 and P < 0.05, 60 differentially changed metabolites (DCMs) were identified. Meanwhile, the presence of Lactobacillus was positively correlated with 54 DCMs (P < 0.05, |r| > 0.5), including tryptophyl-threonine and (5R)-5-hydroxyhexanoic acid. Conversely, a negative correlation was observed between the presence of Monascus and these 54 DCMs (P < 0.05, |r| > 0.5). This study has the potential to enhance the processing theory of fermented meat products and establish a solid theoretical foundation for the control and enhancement of the quality of Midu Juanti. • Co-fermentation of plant derived and animal as raw materials of Midu Juanti. • The microbial community and metabolic characteristics of Midu Juanti was revealed. • Lactobacillus , Monascus and Pichia were dominant microorganisms in Midu Juanti. • The metabolic profile consists mainly of lipids and lipid-like molecules. • Lactobacillus , Monascus and Pichia showed strong correlation with metabolites. [ABSTRACT FROM AUTHOR]