Mycotoxin reduction through lactic acid fermentation: Evidence from commercial ogi processors in southwest Nigeria

This work demonstrates the feasibility of a traditional food processing method to reduce mycotoxins (toxins produced by foodborne molds) in commercial processing plants in Nigeria. Aflatoxin, a commonly occurring mycotoxin in maize and nuts, causes liver cancer in humans, and has also been implicated in child growth impairment and immunotoxicity. Although fumonisin, another mycotoxin in maize, has not been conclusively linked to any human diseases, it causes multiple adverse effects in other animal species and may play a contributory role in neural tube defects and growth impairment in human children. This study examined the impact of lactic acid fermentation, a food processing method used for millennia across multiple human populations, to decrease aflatoxins and fumonisins in maize products in Nigeria. We assessed the prevalence of four aflatoxins and three fumonisins in matched samples of maize grain and a Nigerian porridge ogi (before and after processing) obtained from commercial ogi processors in three southwestern Nigerian states. After processing, the mean total aflatoxin level in the final product was typically close to the maximum acceptable limit shared by Nigeria and the European Union: 4 μg/kg. Lactic acid fermentation significantly reduced fumonisin levels in maize. As ogi is a common weaning food for Nigerian children, the fermentation process used to produce it is potentially beneficial in reducing mycotoxin-related health risks in a sensitive population. It is encouraging to see that mycotoxin reductions occur even in commercial ogi production settings. However, the ultimate fate of these toxins warrants further investigation before this can be recommended as a public health intervention.