Natural occurrence of aflatoxins and ochratoxin A in raw and roasted groundnut from Niger State, Nigeri

Abstract

Aflatoxins (AFs) and ochratoxin A (OTA) contamination of raw and roasted groundnut from Niger State, Nigeria was assessed. Eighty-one samples were randomly collected during the rainy season (May–October) from different locations in four microclimatic zones of Niger State and analyzed for aflatoxin B1 (AFB1), AFB2 and OTA using high performance liquid chromatography. The three mycotoxins (AFB1, AFB2 and OTA) were found in 88.9, 75.3 and 90.1% of the samples respectively and the concentrations ranged 4.0–188 µg/kg for AFB1, 0.4–38.4 µg/kg for AFB2 and 0.8–45.6 µg/kg for OTA. All aflatoxin positive groundnut samples contained levels above the Nigerian and European Union (2 µg/kg) action limits for AFB1 while 55% of the samples had OTA concentrations exceeding the 5 µg/kg regulatory limit of Nigeria and EU. Since groundnut is a staple food in Nigeria, consumption of contaminated kernels may contribute to an increased dietary exposure to AF and OTA in the studied population with possible health risks associated with such exposures.