Maize flour contaminated with toxigenic fungi and mycotoxins in Kenya

ABSTRACT

"The majority of the Kenyan human population may be exposed to regular doses of a wide spectrum of highly toxic; carcinogenic; immunosuppressive; mutagenic; and hepatotoxic mycotoxins through the consumption of maizemeal. Maizemeal is consumed in Kenya at the rate of about 0.4kg/person/day; therefore; even the lowest amount of toxins consumed can cause significant effects as some are cumulative. Maize is also a major component in livestock and poultry feed; and the therefore regular indirect human exposure through the consumption of animal products that contain mycotoxin residues could be common. Due to these suspected risks; it is imperative to establish whether consumers in Kenya are actually exposed to dangerous mycotoxins in maize products hence this survey. Forty samples of flour packed in 90kg bags; 58 samples of ""Ugali"" brand (milled and packed by the Milling Corporation of Kenya Ltd); and 74 samples of ""Jagoo"" brand (Unga Maize Millers) were collected from the Nairobi area. The samples were analysed for resident mycoflora; and some mycotoxins associated with key fungal species. Important fungal species isolated from the flour included Aspergillus lavuss; A. sulphureus; fusarium moniliforme; penicillium stoloniferum; and P. cyclopium. All the three brands of flour were contaminated with Aflatoxins B1 and B2 (0.4-20 ug/kg); ochratoxin A(50-1;500 ug/kg); and Zearalenone (2;500 - 5;000 ug/kg). Ochratoxin A was the most prevalent mycotoxin. These data provide a warning that the mycotoxin contamination problem in maizemeal is critical and consumers' health is at risk. Therefore; rigorous countrywide monitoring of mycotoxins in this staple food should be pursued. If possible; maize products should be subjected to stiff microbial quality control from the farm gate to the market shelf."