Effect of different roasting levels and particle sizes on ochratoxin A concentration in coffee beans

Contamination of roasted coffee with ochratoxin A (OTA) is directly related to the processing quality throughout the coffee production chain, from the farming to the roasting processes. The aim of this study was to evaluate the effects of roasting and particle size on the residual concentration of ochratoxin A in roasted and ground coffee. Coffee beans were artificially contaminated with Aspergillus ochraceus. The beans were roasted to three levels (light, medium and dark) and ground into three types (fine, medium and coarse) after an incubation period. OTA quantification was performed using high-performance liquid chromatography. The combination of dark roast and coarse particle size had the lowest concentration of OTA, 3.06 μg/kg with a 97.17% reduction. The results of this study show that roasting and particle size, rather than roasting alone, are critical for the residual concentration of OTA in roasted and ground coffee beans.