Mycotoxin levels and characterization of natural anti-fungal phytochemicals in pearl millet (Pennisetum glaucum) from Nigeria's six agroecological zones

Mycotoxin Res. 2022 Nov;38(4):243-252. doi: 10.1007/s12550-022-00465-z. Epub 2022 Aug 3.

Abstract

This study reports levels of multiple mycotoxins across Nigeria's six agro-ecological zones and corresponding levels of natural anti-fungal phytochemicals present in pearl millet (PM). 220 representative composite samples of PM were collected for mycotoxin analysis using ultrahigh performance liquid chromatography-mass spectrometry (UHPLC-MS), and 24 were randomly selected for determination of metabolites using gas chromatography-high resolution time of flight-mass spectrometry (GC-HRTOF-MS). In total, 15 mycotoxins were detected, all with levels below the European Union (EU) permissible limits and level of aflatoxins only up to 1.34 µg/kg. This is in sharp contrast to high levels of mycotoxins reported in maize samples from the same agroecological zones. Phytochemical analysis of the same samples identified a total of 88 metabolites, 30 of which are known anti-fungal properties from other previously published studies. The most common of these include methyl ester, bis (2-ethylhexyl) phthalate, and ç-tocopherol. The number of anti-fungal metabolites recovered from each sample ranged from 3 to 17 and varied widely in both number and composition across the agroecological zones. The anti-fungal metabolites may probably make PM less susceptible to fungal proliferation compared to other grains. Hence, it is worth exploring for possible sources of biological control products from PM.

Keywords: Anti-fungal metabolites; Mycotoxins; Nigeria; Pearl millet; Phytochemicals.

MeSH terms

  • Aflatoxins*
  • Esters
  • Mycotoxins* / analysis
  • Nigeria
  • Pennisetum* / microbiology
  • Phytochemicals
  • Tocopherols

Substances

  • Mycotoxins
  • Aflatoxins
  • Phytochemicals
  • Tocopherols
  • Esters