Occurrence of Ochratoxin A in coffee beans, ground roasted coffee and soluble coffee and method validation

The purpose of this work was to determine the occurrence of Ochratoxin A (OTA) in coffee beans, ground roasted coffee and soluble coffee, which is imported by Argentina and manufactured in this country and also to perform a single laboratory validation for the analysis of OTA. Validation was done with certified reference material and with spiked samples. Certified material showed 104% of toxin recovery in the case of roasted coffee and 100% for green coffee. Spiked samples with levels from 1.98 to 10.18 mu g/kg for soluble coffee had an average recovery rate of 79.4%. The limits of detection and quantification in coffee were 0.02 mu g/kg and 0.05 mu g/kg respectively. A good correlation (r = 0.9989) was found for this method. Fifty one samples were investigated to determine the presence of OTA, extracted by Ochraprep (R) immunoaffinity columns for cleaning up and analysed by high performance liquid chromatography (HPLC). The results showed that a high percentage (69%) of the coffee was contaminated with OTA at different levels. The median obtained for green coffee was 2.7 mu g/kg, for ground roasted coffee was 0.24 mu g/kg and 0.43 mu g/kg for soluble coffee. A possible exposure assessment was evaluated. (C) 2012 Elsevier Ltd. All rights reserved.