Fluorescence polarisation immunoassays for rapid determination of mycotoxins in foodstuffs

Mycotoxins are naturally occurring toxic metabolites produced by filamentous fungi under a wide range of climatic conditions on different agricultural crops during growth, drying and subsequent storage. Monitoring, control, risk assessment and prevention of mycotoxins in foods are important issues worldwide associated with public health, agricultural production, food processing and trade. For these reasons the European Commission has set recommended levels or maximum permitted levels for mycotoxins of major concern in a wide range of foodstuffs. Analytical methods for the determination of mycotoxins in foods are commonly based on chromatographic techniques (GC, HPLC or LC-MS). Although these methods permit a sensitive and accurate determination of the analyte, they require skilled personnel and are time-consuming, expensive, and unsuitable for screening purposes. Simple, rapid, and more effective screening methods for mycotoxins determination are highly demanded. Fluorescence polarization immunoassay (FPIA) is a homogenous assay that measures competition between a fluorescently labelled antigen (tracer) and unlabelled antigen in solution for binding a specific antibody. The FP signal is inversely related to the antigen content that competes with the tracer, and it increases when the binding of specific antibody to the tracer increases. Unlike most immunoassays (e.g., ELISA), the main advantage of this format is that additional manipulation steps, as multiple washing steps or separation of free from antibody-bound analyte, are not necessary. The selection of the appropriate antibody-tracer combination determines the speed, accuracy, precision and sensitivity of a FPIA. Incubation times, cross-reactivity, compatibility with organic solvents and matrix effects are analytical parameters to be evaluated and optimized in the development of a FPIA. We have recently developed several FPIAs for the determination of mycotoxins in cereals and processed products, including deoxynivalenol in wheat and derived products, ochratoxin A in wheat, T-2 and HT-2 toxins in wheat, barley, oats and oatflakes [1-3]. An accurate validation of these assays has been performed on each tested matrix using either artificially and naturally contaminated samples, and reference materials. These FPIAs are rapid, easy-to-use, readily automated, and suitable for high-throughput screening as well as for the quantitative determination of mycotoxins in foodstuffs at levels below regulatory levels. Acknowledgements Parts of the work have been supported by the Italian AGER (Agro-Food and Research, project "From Seed to Pasta") and the Italian Ministry of Education, University and Research, MIUR (P.O.N. "Ricerca & Competitività" 2007-2013), project no. 02_00186_341751212792 - S.I.Mi.S.A. "New Strategies for Improvement of Food Safety: Prevention, Control, Correction". References 1.Valenzano S., Lippolis V., Pascale M., De Marco A., Maragos C.M., Suman M. and Visconti A., 2013. Determination of deoxynivalenol in wheat bran and whole-wheat flour by fluorescence polarization immunoassay. Food Analytical Methods, DOI 10.1007/s12161-013-9684-7. 2.Lippolis V., Pascale M., Valenzano S., Porricelli A.C.R., Suman M. and Visconti A., 2014. Fluorescence polarization immunoassay for rapid, accurate and sensitive determination of ochratoxin A in wheat. Food Analytical Methods, 7:298-307. 3.Lippolis V., Pascale M., Valenzano S., Pluchinotta V., Baumgartner S., Krska R. and Visconti A., 2011. A rapid fluorescence polarization immunoassay for the determination of T-2 and HT-2 toxins in wheat. Analytical and Bioanalytical Chemistry, 401:2561-2571.