A limited survey of mycotoxins in traditional maize based opaque beers in Malawi

A total of 9 traditional maize based opaque beers were randomly collected from tribal (chewa) rituals and commercial village brewers from Lilongwe and Dowa districts, Malawi in August 2012 for evaluation of mycotoxins using a multi-mycotoxin method based on liquid chromatography-tandem mass spectrometry. Samples were analyzed for aflatoxins B1 (AFB1), AFB2, AFG1, AFG2, fumonisin B1 (FB1), FB2, FB3, zearalenone, ochratoxin A, nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxynivalenol, neosolaniol, fusarenon-X diacetoxyscirpenol, HT-2 toxin, T-2 toxin, alternariol, alternariol methyl ether, and sterigmatocystin. All beer samples were positive for fumonisins with FB1 + FB2 and FB1 + FB2 + FB3 content of 1745 ± 1294 μg/kg (mean ± std. dev.) and 1898 ± 1405 μg/kg respectively. With exception of one beer sample, all the beers also contained aflatoxins at a mean concentration of 90 ± 95 μg/kg. Consumption of 1.0-6.0 L of the traditional beer from this study translates to daily FB1 + FB2 exposure of 29-174 μg/kg body weight (bw)/day (i.e. >provisional maximum tolerable daily intake of 2 μg/kg bw/day set by the Joint FAO/WHO Expert Committee on Food Additives) and aflatoxin exposure of 1.5-9.0 μg/kg bw/day for a 60 kg adult. The study demonstrated that the consumption of the maize based traditional home-made beer in Malawi can significantly enhance aflatoxins and fumonisin dietary exposure among beer consumers.