Evaluation of Five Major Mycotoxins Co-contaminating Two Cereal Grains from Nigeria

Abstract

Evaluation of Five Major Mycotoxins Co-contaminating Two Cereal Grains from Nigeria Aims: The aim of this study was to determine the co-occurrence of five major mycotoxins in two Nigerian cereal grains destined for human consumption. Study Design: Nigeria experiences high humidity and high temperatures for up to three-quarters of the year; and these are some of the conditions that promote mycotoxin production by filamentous fungi in food commodities. In this regard, rice and maize samples were collected from stores and markets in South Eastern and South Western Nigeria and evaluated for occurrence of five major mycotoxins- aflatoxins (AFs), ochratoxin A (OTA), fumonisin B1 (FB1), Fumonisin B2 (FB2), deoxynivalenol (DON) and zearalenone (ZEA). Place and Duration of Study: The study was part of a Masters dissertation developed in the Food, Environment and Health Research Group, Faculty of Health Sciences, University of Johannesburg. Methodology: Imploring three different extraction procedures, mycotoxin occurrence and levels were determined via thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Results: Results showed high incidences of all five mycotoxins in both samples with OTA highest in rice samples (92.7%), while AFs and FB1 had highest incidence in maize samples (94.9%). Data from HPLC analysis of rice and maize samples showed different concentration range of mycotoxins AFs (0.01-6.50 µg/kg and 0.07-109.78 µg/kg); OTA (0.7-180.9 µg/kg, 0.6-79.0 µg/kg; FB1 (0.9-59.6 µg/kg, 10.0-3644.0 µg/kg); ZEA (0.7-570.6 µg/kg, 1.8-652.3 µg/kg) and DON (0.1-0.7 µg/kg, 0.1-0.7 µg/kg) respectively. Conclusion: Mycotoxins concentration determined in the food samples were above Nigerian and European Union (EU) set limits. The co-occurrence of these mycotoxins in food samples analysed in this study gives further awareness to the health risks consumers of these food commodities are exposed to. The study also contributes to research being done in Nigeria in other to understand the degree of mycotoxins contamination of food consumed by the populace.