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.

Keywords:

• Fumonisin B1
• zearalenone
• α-zearalenol
• β-zearalenol
• enniatins
• Fusarium species
• maize
• Nigeria

Acknowledgements

This work was funded by the Alexander von Humboldt Foundation (AvH), Germany, through the award of a Georg Forster Research Fellowship to the senior author. Its support is gratefully acknowledged.