The role of wet fermentation in enhancing coffee flavor, aroma and sensory quality

Abstract

This study investigates the impact of wet fermentation on flavor volatiles and sensory quality of coffee beans and beverage. Pulped coffee beans were kept underwater for 36 h before air-drying and roasting, and volatiles in the beans were characterized by solid-phase microextraction and gas chromatography–mass spectrometry. A total of 79 volatiles were identified. Fermented roasted beans had higher concentrations of ethanol, isoamyl alcohol, 3-methylbutanal, benzaldehyde, acetaldehyde, and ethyl acetate compared with mechanically processed (no fermentation) beans; whereas, ketones, pyrazines, pyrroles, pyridines, furans and sulfides were not significantly different between the two treatments. Coffee made with fermented beans was rated significantly higher in flavor, aroma, acidity, body and uniformity scores with noted fruity aroma compared with beverage made with mechanically processed beans in sensory evaluation (cup test) by a 3 Q-Grade Coffee Certification Panel. The findings demonstrated wet fermentation played an important role in coffee flavor, aroma and sensory quality.