Prevalence and distribution of aflatoxin (AfB1) in groundnut and groundnut-based products in Northwestern Nigeria

The kernel of groundnut and groundnut-based products are easily contaminated by aflatoxin: a mycotoxin produced by the fungus Aspergillus flavus and A. parasiticus. A total of 526 samples of groundnut and groundnut-based products were collected from six states in Nigeria namely Kano, Jigawa, Katsina, Kebbi, Sokoto and Benue States and analyzed for Aflatoxin B1 (AfB1) contamination using the Enzyme-linked Immunosorbent Assay (ELISA) technique. Results of the analysis revealed that both groundnut kernel and processed products had varying levels of AfB1 contamination. While AfB1 contamination levels varied between 7.82 and 12.33 µg/kg in kernels of local groundnut varieties, they ranged between 3.79 and 6.79 µg/kg in those of improved groundnut varieties. Mean AfB1 levels in groundnut-based products ranged from 12.30 to 99.37 µg/kg, with the highest recorded in kuli-kuli - a by-product of groundnut oil processing. Variability between mean AfB1 contamination levels in groundnut kernels of improved and local varieties were significant while no statistical difference was found between mean AfB1 contamination levels in groundnut kernels between/amongst the states. Outcomes of the study suggest that an integrated approach including the use of improved groundnut varieties, appropriate crop management practices and awareness creation on food safety, and notably on aflatoxin, could mitigate contamination in the groundnut value chain. Key words: Aflatoxin B1, prevalence, groundnut, distribution, Nigeria.