Metagenomic, metabolomic, and sensorial characteristics of fermented <i>Coffea arabica</i> L. var. Castillo beans inoculated with microbial starter cultures

Our study demonstrates that inoculating coffee fermentation alters the sensory qualities of coffee and reshapes the dynamics of bacterial and fungal communities during this process. We identified distinct changes in microbial diversity and metabolite composition associated with inoculation, which correlated with improved sensory attributes. In addition, we detected aminophenol and phenol at higher levels in spontaneously fermented coffees, compounds that are likely responsible for phenolic defects. To our knowledge, this is the first report directly linking these compounds to defective flavor notes in coffee. Together, these findings show that inoculation not only enhances desirable flavor profiles but may also serve as a strategy to reduce the risk of cup defects by modulating the fermentation microbiota. Our work advances the understanding of community-level microbial processes in coffee fermentation and opens opportunities for developing techniques to produce coffee with unique, high-quality, and reproducible sensory characteristics.