Dynamic Changes of Microbial Communities and Chemical Compounds During the Dry Processing of Coffea arabica.

Coffee is a globally popular beverage and a significant agricultural economic crop in planted countries and regions. To understand the influence of primary processing on coffee, the microbial communities and chemical compounds were analyzed using high-throughput sequencing and HPLC-MS/MS metabolomics to confirm the dynamic changes of them during the dry processing of Coffea arabica from Yunnan, China. The results showed that Tatumella, Klebsiella, Gluconobacter, Brevundimonas, and Staphylococcus at the bacterial general level and Candida, Lachancea, Aschersonia, Cercospora, and Pichia at the fungi general level were the predominant microorganisms in the dry processing. During the dry process, Tatumella, Gluconobacter, and Candida showed a trend of increasing firstly and decreasing subsequently, while Klebsiella and Lachancea reached the highest at the end of processing. In contrast, Hannaella decreased gradually. Meanwhile, 1551 chemical compounds coming from 15 superclasses were detected. Furthermore, 129 differentially changed compounds (DCCs) including 91 upregulated DCCs with VIP > 1.0, p < 0.05, and FC > 1.5 and 38 downregulated DCCs with VIP > 1.0, p < 0.05, and FC < 0.67 were determined in finished samples versus raw materials. Among them, cis-5-caffeoylquinic acid and sesamose were very significantly DCCs. Therefore, this study can provide useful information for understanding the dry processing of coffee beans and its impact on coffee's quality properties.