Assessment of Aflatoxin Contamination in Stored Groundnuts Sold in Maiduguri Markets, Borno State

Groundnut is a widely consumed oilseed crop in the North East geopolitical zone of Nigeria, commonly traded in markets across Borno State. However, improper storage conditions, combined with the hot and semi-arid climate, create conducive environments for Aspergillus species proliferation and subsequent aflatoxin production. This study assessed the level of aflatoxin contamination in stored groundnut samples obtained from four major markets in Maiduguri: Monday Market, Gamboru Market, Custom Market, and Kasuwan Shanu. A total of forty-eight samples were collected, sixteen each from retailers, wholesalers, and smallholder farmers. Aflatoxin B1, B2, G1, and G2 levels were determined using enzyme-linked immunosorbent assay with results confirmed by high performance liquid chromatography. Results showed that 58.3 percent of all samples exceeded the European Union maximum residue limit of 2 micrograms per kilogram for aflatoxin B1. Samples stored in polypropylene bags on earthen floors showed significantly higher contamination than those stored in metallic silos. Moisture content above 9 percent was consistently associated with elevated aflatoxin levels. The study recommends training of market actors on proper storage protocols, promotion of hermetic storage bags, and strengthened enforcement of food safety regulations by the Borno State Quality Control Agency. Keywords: aflatoxin, groundnut, contamination, storage, Maiduguri.