IDENTIFICATION OF FUNGI AND MYCOTOXINS ASSOCIATED WITH COFFE BEAN ON CHIAPAS, MEXICO.

Abstract

Objective: To identify the mycobiota associated to coffee beans (Coffea sp.) collected in the state of Chiapas, Mexico, as well as the incidence and levels of contamination by total aflatoxins and ochratoxin A.
Design/methodology/approach: To obtain representative samples of coffee beans, visits were made to the main producing and storage areas in seven regions of Chiapas, from March 2006 to December 2007. From each sample, 100 grains were taken, sterilized and sown in PDA medium. The isolated fungi were identified at genus or species level. The identification of mycotoxins was performed by ELISA and the Ridasoft Win Software version 1.45 was used for their quantification.
Results: Twenty-five genera/species of fungi were identified, with Aspergillus being the prevalent genus, followed by Penicillium, Fusarium, Curvularia, Rhizopus, Helminthosporium and Pestalotia. A. niger, A. flavus, A. ochraceus and A. clavatum were identified. There was a difference in the incidence of fungi between grain type and sampling regions. Regarding mycotoxins, there were differences according to type of grain and origin of the sample. Total aflatoxins were not found at high levels, but high levels were found for ochratoxin A.
Study limitations/implications: Total aflatoxins in coffee do not show levels of risk to health, but ochratoxin A is present in risky levels for human health.
Findings/conclusions: The incidence of fungi and contamination with mycotoxins is variable, depending on the type of coffee bean, region and year of sampling.