Evaluation of the effects of temperature on processed coffee beans in the presence of fungi and ochratoxin A

Abstract

The coffee bean is sensitive to contamination with ocratoxigenic fungi; temperature influences the growth, and germination of these fungi, as well as the fungal toxins produced. The objectives of this study were to assess the distribution of toxigenic species, analyze the concentration of ochratoxin A (OTA) in Arabica coffee beans, and aplicate a mathematical model that considers the influence of actual temperature to predict the effects of projected temperature increase on OTA production. This toxin was, however, not detected in any of the coffee bean species analyzed here. The species with the highest incidence were Aspergillus niger and Aspergillus ochraceus. The results of the mathematical model demonstrated the influence of temperature on the production of the toxin. This information indicates the distribution of toxigenic fungal species in the regions of coffee cultivation in Minas Gerais, and thus, will assist the producers in adopting preventive measures. Practical applications Brazil is the largest coffee producer and exporter, which makes it a leader in the global coffee market; the state of Minas Gerais is responsible for 50% of this production. Following the global trend, Brazil has regulated the maximum permissible limit for ochratoxin A in coffee beans. This has led to a great interest in monitoring fungi and toxin production, mainly during the postharvest stage in the coffee cultivation regions of Brazil. Preventive measures can aid in the safe production of coffee beans, and the use of mathematical models capable of predicting the growth and production of fungal toxins are fundamental to informing the producers of the most favorable conditions in terms of temperature, as well as increases in ambient temperature, in specific regions of interest.