Co-occurrence of deoxynivalenol and zearalenone in crops marketed in Portugal.

A total of 307-samples of plant crops (both home-grown and imported) marketed in Portugal, including maize and maize-based products (132), wheat and wheat-based products (82), barley (25), soybean (53), sunflower (8) and alfalfa (7), were analyzed for the co-occurrence of the Fusarium toxins, zearalenone (ZEA) and deoxynivalenol (DON). Analysis for ZEA and DON was carried out by HPLC, with fluorescence and UV detection, respectively. Of the 307 samples, ZEA and DON co-occurred in 46 samples (co-occurrence of 15?); 84 samples were DON-positive and 171 were ZEA-positive. The mean ZEA and DON concentrations were 0.17 and 0.07 mg kg(-1), respectively. The highest levels found in the samples were 0.93 mg kg(-1) for ZEA and 17.9 mg kg(-1) for DON. One DON-positive and 13 ZEA-positive samples had contamination levels above the EU maximum legal limit.