Aflatoxin and fumonisin contamination of yam flour from markets in Nigeria

The natural occurrence of aflatoxins (AFs) and fumonisins (FBs) in yam flour samples (n = 100) obtained in south-western Nigeria was evaluated. AFs were determined by HPLC with fluorescence detection and FBs by HPLC coupled with mass spectrometry. Aflatoxin B1 (AFB1) and aflatoxin G1 (AFG1) were found in 57% and 21% of flours from white yam with concentrations ranging from <0.02 (limit of detection, LOD) to 3.2 μg kg−1 (mean = 0.4 μg kg−1) and from <0.05 to 3.5 μg kg−1, respectively. AFB1 was the only aflatoxin detected in samples from water yam, contaminating 32% of the samples with values ranging from