Occurrence of aflatoxin M1 from rural subsistence and commercial farms from selected areas of South Africa

Abstract

Aflatoxin M1 (AFM1) is a hydroxylated metabolite of aflatoxin B1 and its presence in milk is considered to be a potential health risk for humans. Due to the important role of milk in humans, especially in infant nutrition, this study is intended to evaluate the quality of milk consumed on daily basis in South Africa by both rural and urban population in regard to AFM1 contamination. To achieve this, samples were collected from rural subsistence (RSFs) and commercial dairy farms (CDFs) in selected areas of South Africa and samples were extracted using two clean-up procedures, C18 cartridges and immunoaffinity columns (IAC) and analysed using thin layer chromatography (TLC) or by fluorometry (VICAM) (VF) and high pressure liquid chromatography (HPLC) coupled with a fluorescence detector and a coring cell (CoBrA cell) for AFM1 derivatisation. Results obtained showed a frequency of contamination with AFM1 of RSFs milk samples at 22.8% by TLC, 93.9% by VF 86% by HPLC and in CDFs of 17.8% (TLC) 96.5% (VF) and 100% (HPLC). No significant differences were obtained between milk from rural subsistence and commercial farms with mean varying between 0.15 and 0.17 μg kg−1