Exposure to fumonsins through kenkey: a Ghanaian fermented maize product

Abstract

Fumonisins are a group of mycotoxins produced mainly by Fusarium verticillioides [= F. moniliformeJ, F. proliferatum, and several other Fusarium species that are widespread in maize throughout the world. The most popular way of consuming maize, a dietary staple in Ghana, is in the form of Kenkey, a ready-to-eat food. For the preparation of Kenkey, maize kernels are steeped, milled, fermented, moulded, wrapped in maize husks and boiled for 3 hours. There is however a growing concern that a high dietary intake of maize-based foods, notably Ken key, may expose consumers in Ghana to fumonisins. The study measured fumonisin levels in maize and Kenkey from 75 maize processing sites in Ghana. The maize and Kenkey samples were analysed for fumonisins using HPLC after extraction and clean-up on either strong anion exchange (SAX) or reversed-phase (CIS) cartridges respectively. More than 90% of the maize samples contained fumonisins ranging from 11 to 2,534 ug/kg whilst over 70% of the Kenkey samples also contained fumonisins at levels ranging from 15 to 1,035 ug/kg confirming the direct intake of fumonisins. Further experiments to determine the fate of fumonisins during the preparation of Kenkey using maize naturally contaminated with fumonisins at different levels revealed significant reductions during the 48-hour steeping stage. Reduction levels were dependent on the initial fumonisin content of the maize kernels. Fumonisin BI was reduced by between 59 and 86%. The initial fumonisin Bl content of the maize kernel samples ranged from 1,206 to 78 ug/kg. Reductions in fumonisin levels ranged from 16 to 31% for fumonisin B₂ and between 57 and 64% for fumonisin B₃. No significant changes in fumonisin levels were recorded during the three-day fermentation and the three-hour boiling processes. This study has established the carry-over of fumonisins from maize into Kenkey and the possible risk posed to consumers