Survey of ergosterol, zearalenone and trichothecene contamination in maize from Nigeria

The contents of ergosterol, zearalenone (ZEA) and a spectrum of A- and B-types of 13 trichothecene toxins in maize samples destined for human consumption from farmers’ stores and markets in Nigeria in 2005 and 2006 were determined. Ergosterol was analysed by HPLC with UV-detection, ZEA by HPLC with fluorescence and UV-detection, while trichothecenes were determined by gas chromatography/mass spectrometry. Ergosterol was detected in 105 of the 106 samples at concentrations ranging from 0.1 to 24.2 μg g−1. ZEA was found in 4 out of 69 samples at 2–13 μg kg−1. Out of the 32 samples analysed for trichothecenes, only one sample was contaminated with 15-monoacetoxyscirpenol (15-MAS) at 4 μg kg−1, and two samples were contaminated with T-2 tetraol at levels of 73 and 280 μg kg−1. Nivalenol (NIV), scirpentriol (SCIRP), deoxynivalenol (DON), fusarenon-X (FUS-X), 15-acetyldeoxynivalenol (15-ADON), 3-acetyldeoxynivalenol (3-ADON), T-2 triol, neosolaniol (NEO), 4,15-diacetoxyscirpenol (4,15-DAS), HT-2 and T-2 toxins (HT-2, T-2) were not detected in any of the samples. Thus in spite of the limited number of samples investigated, it seems to be obvious that zearalenone and trichothecene toxins do not appear to be major contaminants of Nigerian maize. The significantly higher ergosterol levels in maize that had been stored for 9 months compared with those of maize that had been stored for 4 months or less, point to the inadequacy of currently used storage methods in preventing deterioration. This is the first report of ergosterol levels in Nigerian maize.