Three-year multi-mycotoxin analysis of South African commercial maize from three provinces.

Introduction: The Food and Agricultural Organization (FAO) reported that numerous diseases can be traced back to the consumption of unsafe food contaminated with mycotoxins. Mycotoxins are secondary metabolites produced by toxigenic filamentous fungi. Mycotoxins reported to be of socio-economic concerns include aflatoxins, fumonisins, zearalenone, ochratoxin A, and deoxynivalenol. These mycotoxins are frequent contaminants of maize especially in the face of climate change and global food insecurity. South Africa is a leading exporter of maize in Africa, hence, it is crucial to evaluate exposure risks with respect to mycotoxin contamination of maize for consumers' safety. Materials and method: In total, 752 post-harvest maize samples collected from silos over a 3-year period were analysed using liquid chromatography with tandem mass spectrometry (LC-MS/MS) for the occurrence of mycotoxins. Results and discussion: The overall mean values for all the quantified mycotoxins were within the South Africa regulatory limit as well as the individual samples, apart from DON and FB mycotoxins with 5% and 1% samples, respectively, above the limit. Citrinin was quantified in South African commercial maize for the first time. The presence of major mycotoxins in South African commercial maize even within safety limits is of public health concern, hence, continuous monitoring and evaluation is recommended.