Fate of Mycotoxins in Local-Race Populations of Maize Collected in the Southwest of France, from the Field to the Flour and Meal in Organic Farms

Both organic and conventional farmers are confronted with the issue of mycotoxin contamination of maize, but organic farming is considered by the public to present a higher risk. There are also concerns about the sanitary quality of maize processed as a foodstuff and marketed on farms through short distribution channels, and there is a need for data on mycotoxin contamination in such a farming system. With the objective to assess the diversity of contamination levels at harvest and to track the post-harvest fate of mycotoxins, maize grain samples were collected at organic farms from southwest France after harvest, storage and milling. There was a wide range of levels of contamination by trichothecenes A and B, zearalenone, and fumonisins. The presence of ochratoxin A and aflatoxins was scarce. In some farms, but not all, the technique of drying and initial storage in cribs resulted in increased levels of contamination by Fusarium toxins, but not aflatoxins. The transfer of mycotoxins in milling products was higher for flour than for meal. Data are discussed in terms of mycotoxin co-occurrence, correlations between concentrations, and compliance with European Union regulations.