Potential of lactic acid fermentation in reducing aflatoxin B1 in Tanzania maize-based gruel

Abstract

Aflatoxins are toxic by-products of fungi, with harmful effects on human and animal health. Although maize is known to be highly susceptible to aflatoxin contamination, and a staple in many African countries, there is still lack of methods to mitigate the effects. The effect of lactic acid fermentation on reduction of aflatoxin B₁ in Tanzania maize-based gruel (togwa) by four monocultures (Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus casei and Lactobacillus fermentum), natural fermentation and back-slopping at 30°C for up to 24 h was investigated. Monocultures removed 45–55% of aflatoxin B₁ while natural fermentation and back-slopping removed 56% and 68% of aflatoxin B₁, respectively. Thus, lactic acid fermentation could be a part of a comprehensive mycotoxicosis prevention strategy in the commonly consumed maize-based gruels. Consumers could benefit from enhanced food safety through consumption of gruel less contaminated with mycotoxins and might also benefit from the probiotic effects of lactic acid bacteria. In the scenario where lactic acid bacteria starter culture access and handling could prove challenging, especially to households and small-scale food processors in developing countries, the use of back-slopping in gruel fermentation might be advocated for in order to reduce aflatoxin B₁.

Keywords: aflatoxins, lactic acid fermentation, maize gruel, togwa, food safety, mycotoxins, East Africa