Submitted to: Journal of Food Additives & Contaminants
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2007
Publication Date: 8/29/2007
Citation: Doko, M.B., Whitaker, T.B., Maestroni, B.M., Ogunbanwo, B.F., Slate, A.B. 2007. Survey of fumonisin B1 (FB1) contamination of food-grade commercial maize lots from five geographical areas in Nigeria in 2002. Journal of Food Additives & Contaminants.
Interpretive Summary: Fumonisins, toxic and carcinogenic compounds produced by molds, are found worldwide in maize and maize-based food and feed products. In Africa, fumonisin contamination of maize is a concern because maize is the primary human food and contamination levels may be high because of the lack of quality controls in the production and marketing system. In most African countries, little is known about fumonisin contamination of the food supply. In particular, with no awareness of contamination levels, high incidence of fumonisins in the food supply may present a potential health hazard to the general population and children in particular. Because official monitoring of fumonisin contamination levels is rare in developing countries where contamination is more likely to occur, the International Atomic Energy Agency (IAEA), Technical Cooperation (TC) Department, Division for Africa, developed a project to determine the incidence and contamination levels of fumonisin in 100 maize lots marketed in five geographical locations (Lagos, Ibadan, Maiduguri, Kaduna, and Enugu) in Nigeria. Fumonisin was found in all 100 lots. Levels varied from a low of 10,000 parts per billion to a high of 2,980,000 parts per billion. The study demonstrated that fumonisin is prevalent in maize marketed in Nigeria and requires development of control measures and regulatory limits to reduce contamination in the maize supply.
Technical Abstract: Samples from a total of 87 food-grade maize lots intended for human consumption purchased in 2002 from local cereal markets and maize retail outlets in Lagos (18 lots), Ibadan (20 lots), Maiduguri (17 lots), Kaduna (16 lots), and Enugu (16 lots), Nigeria were tested for fumonisin B1 (FB1). Approximately twenty 100 g samples were taken from each lot at each location and tested for FB1 by HPLC-Fluorescent detection technique, using pre-column OPA derivatives method (detection limit = 0.010 'g/g FB1). For the survey study, the FB1 concentration of a lot was estimated by averaging all sample values from the same lot. Hundred percent of the lots surveyed tested positive for FB1. The FB1 concentration among the 87 lots marketed in Nigeria varied from a low of 0.01 'g/g to a high of 2.98 'g/g FB1 and averaged 0.905 'g/g FB1. In maize lots from Ibadan and Enugu, the FB1 levels averaged 0.67 and 0.70 µg/g, respectively; whilst higher FB1 contamination levels of 0.97; 1.06; and 1.15 µg/g were reached in maize lots from Maiduguri, Kaduna and Lagos, respectively. While all 87 lots were contaminated with FB1, the overall results indicate that relatively low levels were encountered in the lots tested in Nigeria. Twenty- eight percent of the 87 lots tested less than 0.50 'g/g FB1 and 67.8% was less than 1.0 'g/g FB1. These findings were consistent with results reported worldwide confirming the widespread of the presence of the fumonisins in maize. This study exhibits the potential risk of consumer’s exposure to fumonisin, especially through the ingestion of poor food quality-grade maize.