AUTHOR=Elhalis Hosam , Cox Julian , Frank Damian , Zhao Jian 

TITLE=Microbiological and Chemical Characteristics of Wet Coffee Fermentation Inoculated With Hansinaspora uvarum and Pichia kudriavzevii and Their Impact on Coffee Sensory Quality

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.713969

DOI=10.3389/fmicb.2021.713969

ISSN=1664-302X

ABSTRACT=<p><italic>Hansinaspora uvarum</italic> and <italic>Pichia kudriavzevii</italic> were used as starter cultures to conduct inoculated wet fermentations of coffee beans, and their growth, metabolic activities and impact on the flavor, aroma and overall sensory quality of coffee were compared with spontaneous fermentation (control). <italic>H. uvarum</italic> and <italic>P. kudriavzevii</italic> dominated the fermentations, growing to maximum populations of about 10.0 log CFU/ml compared with 8.0 log CFU/ml in the spontaneous fermentation. The dominance of the inoculated yeasts led to faster and more complete utilization of sugars in the mucilage, with resultant production of 2–3 fold higher concentrations of metabolites such as glycerol, alcohols, aldehydes, esters, and organic acids in the fermented green beans. Cup tests showed coffee produced from the inoculated fermentations, especially with <italic>P. kudriavzevii</italic>, received higher scores for flavor, aroma and acidity than the control. The findings of this study confirmed the crucial role of yeasts in the wet fermentation of coffee beans and their contribution to high quality coffee, and demonstrated the potential <italic>H. uvarum</italic> and <italic>P. kudriavzevii</italic> as starter cultures in the process.</p>