Development of a new clean-up tandem assay column for the detection of ochratoxin A in roasted coffee

As the mycotoxin ochratoxin A (OTA) can occur in roasted coffee, regulations and maximum limits are necessary. The need for simple, rapid and inexpensive detection methods which require a minimum of equipment led to the development of a clean-up tandem assay column for the detection of OTA in roasted coffee. In this study the column comprised two superposed layers: a layer capable of adsorbing at least part of the interfering fraction of the sample and a detection layer containing antibodies that were able to capture the analyte. No expensive instruments were needed as results were visually evaluated. The cut-off level, i.e. the smallest mycotoxin concentration resulting in no colour development, was 6 mu g kg(-1). Assay validation was performed using samples fortified with OTA. The method gave a low percentage of false negative results and no false positive results. Assay performance was evaluated by screening naturally contaminated samples using the clean-up tandem assay column. The described method offers a rapid, simple and cost-effective screening tool, contributing to more effective quality control procedures. (c) 2005 Elsevier B.V. All rights reserved.