A survey of mycotoxins in random street-vended snacks from Lagos, Nigeria, using QuEChERS-HPLC-MS/MS

A survey in African snacks was carried out in order to evaluate the intake of 23 mycotoxins. The African snack samples were purchased from street vendors within Lagos metropolis (Nigeria) and evaluated for the presence of 23 mycotoxins using a modified QuEChERS procedure coupled with liquid chromatography-triple quadrupole linear ion trap mass spectrometer. The snacks included akara, baked coconut, coconut candy, donkwa, groundnut cake (kulikuli), lafun, milk curd (wara), fresh and dried tiger-nuts, and yam flour. Only three mycotoxins were detected in 23.8% of the studied snacks, and at concentrations ranging from 6 to 54 μg kg−1. The concentrations of aflatoxin B1 (AFB1) and AFB2 reached 23 μg kg−1 and 3 μg kg−1, respectively. Moreover a sample of baked coconut contained α-zearalenol (α-ZOL), which was up to 54 μg kg−1 in coconut candy. As considers prevalence, aflatoxins and α-ZOL were not detected in lafun and groundnut-based snacks (donkwa and kulikuli), whereas each of the three mycotoxins contaminated 12.5% (1/8) of the coconut-based samples. This is the first report of α-ZOL in cassava and coconut, and their products. AFB1 and total aflatoxins (TAFs) concentrations exceeded the maximum allowable limit recommended by National Agency for Food and Drug Administration and Control Nigeria (NAFDAC) in one sample of baked coconut (AFB1 = 23 μg kg−1 and TAFs = 26 μg kg−1) and donkwa (AFB1 = 19 μg kg−1 and TAFs = 21 μg kg−1).

► QuEChERS-LC-QTRAP method was applied to identify 23 mycotoxins in African samples.
► The QuEChERS method allowed 23 mycotoxins to be extracted simultaneously.
► This survey showed that snacks were mainly contaminated by aflatoxins.
► The first time that alfa-ZOL was found in cassava and coconut, and their products.