Lactic acid fermentation improves the quality of amahewu, a traditional South African maize-based porridge

The ability of traditional amahewu fermentation to increase protein digestibility and detoxify mycotoxins commonly contaminating maize in southern Africa was investigated. Commercial maize meal, with or without a range of added ingredients, was fermented, following the traditional way, and the levels of proteins and amino acids assessed. Traditional amahewu samples (and the maize meal used to prepare them) were also collected from a neighbouring rural village. Mycotoxin levels (aflatoxin B1, fumonisin B1 and zearalenone) in maize meal and amahewu were analysed and compared in the two sets of samples. Increased levels of protein were observed in amahewu, especially in the samples with added yeast and bread flour (up to 149%), in comparison to the levels in starter maize. In addition, the mycotoxins detected in maize samples were drastically reduced, by 76.5–100%, following fermentation. This observation shows that traditional amahewu fermentation may improve the nutritional quality of maize-based foods and reduce the levels of toxic/carcinogenic mycotoxins.