Validation of novel immunoassays according to European legislation for the rapid analysis of ochratoxin A in cereal, grape, and dried vine fruit samples

Harmonizing analytical criteria for the validation of rapid methods is fundamental in contemporary food safety analysis. Immunoassays have achieved notable success in mycotoxin detection, particularly due to their suitability for low-resource laboratories and on-site applications. In the present study, two novel monoclonal antibody-based immunoassays were in-house developed and validated for the analysis of ochratoxin A, in line with the latest European regulations. The performance of both methodologies was evaluated using five different cereal grains, two types of grape matrices, and two types of dried vine fruits. Recovery rates and repeatability of the enzyme-based immunoassay meet the European Commission’s criteria for confirmatory methods. Concerning the lateral flow immunoassay, the screening target concentration was aligned with the European maximum permitted levels of ochratoxin A for each food product. The calculated false suspect rates for blank samples were at or below 1%, with a certainty of 95%, consistent with the requirements by the European Commission for semi-quantitative screening methods. The accuracy of both immunoanalytical approaches was confirmed through the analysis of certified reference materials. Finally, a market survey of dried vine fruits revealed one sample exceeding the European legal limit for ochratoxin A, demonstrating the applicability of the methods. • Two monoclonal antibody-based immunoassays have been developed for OTA analysis. • Both methods were validated in whole cereal flours, grapes, and dried vine fruits. • The enzyme immunoassay was compliant with European criteria for confirmatory assays. • The lateral flow assay aligned well with European criteria for screening assays. • A brief market survey revealed one raisin sample with exceeding OTA contents.