Survey of maize from south-western Nigeria for zearalenone, α - and β -zearalenols, fumonisin B1 and enniatins produced by Fusarium species

Abstract

A survey for the natural occurrence of Fusarium mycotoxins in maize for human consumption in four south-western states of Nigeria using High Performance Liquid Chromatography coupled with Mass Spectroscopy (HPLC/MS) showed that 93.4% of the samples were contaminated with zearalenone (ZON), α- and β-zearalenols (α- and β-ZOL), fumonisin B1 (FB1) or enniatins (ENNs). The fractions of contaminated samples were 73% for FB1 (mean:117 µg kg−1, range:10–760 µg kg−1); 57% for ZON (mean:49 µg kg−1, range:115–779 µg kg−1) and 13% for α-ZOL (mean: 63.6 µg kg−1, range:32–181 µg kg−1), while ENNs A1, B and B1 were present in 3, 7 and 3% of the samples respectively. There was no β-ZOL present above the quantification limits of 50 µg kg−1. Only the FB1 content was significantly different at the 95% confidence level among the four states. The Fusarium species most frequently isolated from maize seeds were F. verticillioides (70%), followed by F. sporotrichioides (42%), F. graminearum (30%), F. pallidoroseum (15%), F. compactum (12%), F. proliferatum (12%), F. equiseti (9%), F. acuminatum (8%) and F. subglutinans (4%). This is the first report of the occurrence of α-zearalenol and enniatins in Nigerian maize.