Potential of volatile compounds produced by fungi to influence sensory quality of coffee beverage

Abstract

Fungi are known producers of a large number of volatile compounds (VCs). Several VCs such as 2,4,6 trichloroanisole (TCA), geosmin and terpenes have been found in coffee beverages, and these compounds can be responsible for off-flavor development. However, few studies have related the fungal contamination of coffee with the sensory characteristics of the beverage. The aimof this researchwas to investigate the production of VCs by fungi isolated fromcoffee and their potential asmodifiers of the sensory coffee beverage quality. Three species were isolated from coffee from the southwest of São Paulo state and selected for the study: Penicillium brevicompactum, Aspergillus luchuensis (belonging to section Nigri) and Penicillium sp. nov. (related to Penicillium crustosum). VCs produced by the fungal inoculated in raw coffee beans were extracted and tentatively identified by SPME–GC–MS. Different VCs thatmay interfere in the coffee beverage qualitywere detected in the rawcoffee beans inoculated with these fungal species (mainly A. luchuensis). Oct-1-en-3-ol was detected in the raw coffee inoculatedwith A. luchuensis. This compound,which is characterized by earthy andmoldy/mushroomaroma, can be related to negative characteristics of coffee beverage in sensory analysis. On the other hand, the presence of some fungal species in the coffee, even at a high percentage of infection, did not necessarily result in loss of the sensorial quality of the beverage, since the samples with a high infection of P. brevicompactum showed positive sensory evaluation.