Isolation and characterization of potentially ochratoxigenic fungi from Costa Rican coffee (Coffea arabica L.) beans.

Abstract

Coffee plants and beans are prone to fungal contamination that pose health risks to consumers by producing mycotoxins like ochratoxin A (OTA). Thus, the present study aimed to analyze the mycobiota of Costa Rican coffee beans, focusing on potentially ochratoxigenic species and their in vitro susceptibility patterns to antifungal agents. Fungal isolates were obtained from cherry, green, and roasted coffee beans from Costa Rica; they were identified by morphology, MALDI-TOF technology, and sequencing. The isolation frequency (FR) was 33.10 % for all the samples analyzed, 49.51 % for the cherry fruits, 37.67 % for the green coffee beans, and 17.33 % for the roasted beans. The cherry beans were mainly contaminated with Geotrichum klebahni (46.34 % FR and 90.91 % relative density [RD]), while the green and roasted coffee beans were mainly infected with Aspergillus spp. (22.00 % FR and 55.23 % RD and 13.83 % FR and 77.57 % RD, respectively). A total of 46.67 % of A. westerdijkiae and 20.00 % of A. ochraceus produced fluorescence in YES broth related with ochratoxin production. The isolates of the Aspergillus section Circumdati were susceptible to the azole antifungals. Costa Rican coffee beans could be contaminated with mycotoxigenic fungi during storage.