Aflatoxin contamination of groundnut is a major hazard to human and animal health and is one of the major constraints to the groundnut trade. Risks related to human health and declining productivity in livestock after consuming aflatoxin-contaminated feed have led to groundnut importing countries setting standards that allow only extremely low levels of contamination and that are often not achievable by most resource-poor groundnut farmers. Crop husbandry practices, mechanical damage, insect and bird damage, climatic conditions (drought, stress or excessive rainfall), soil factors etc. significantly influence aflatoxin contamination. Thus, the evaluation of total aflatoxins (TAF) in purchased and processed groundnut (Arachis hypogaea L.) products in some areas (Kwande, Katsina – ala and Gboko) of Benue State, Nigeria was studied using Direct Competitive Enzymes Linked Immunosorbent Assay method (ELISA). Also the mould counts; and mould isolation and identification were done. For each of the purchased groundnut product, 5 sampling locations were earmarked in each of the area and in turn 3 samples collected from each of the locations to form a composite per location. To get the processed products, a sample of raw groundnut was collected from each of the locations and combined to form 1 composite; and the processed into paste, oil and cake. The results implied that in the groundnut cake TAF was detected in all the samples. The levels were below the 20 μg/kg maximum permissible limits (MPL) set by National Agency for Food and Drug Administration and Control (NAFDAC), Nigeria and the 10 μg/kg MPL of the Codex Alimentarius Commission, CAC. More so, the results of TAF in the groundnut oil and paste samples as well were below the above MPL. In addition, though the moisture content of all the studied samples of cake, oil and paste were within the MPL of 15% (cake), 2% (oil) and 30% (paste) in accordance to selected food regulatory Agencies; the results showed a strong positive correlation between the moisture content and the concentration of aflatoxin. Mould count/isolation results indicated that, a total of 305 isolates were identified and Aspergillus flavus with 137 (44.92%) occurrence was observed to be the major isolate among others. In a nutshell, there was no significant difference in the levels of total aflatoxin between the processed and purchased groundnut samples. Therefore, is logical to conclude that the groundnut was infiltrated by aflatoxin on farm and during storage. The contamination was generally moderate in cake and oil but relatively higher in the groundnut paste samples. These mycotoxins are indeed a threat to human and animal health, especially as they cause cancer. The research has revealed that routine check for aflatoxin content in groundnut paste is vital to minimize chances of aflatoxin poisoning from the study areas.
Keywords: Groundnut, Cake, Oil, Paste, Aflatoxin, ELISA, Nigeria