Evaluation of Aflatoxin Contamination in Zea mays (Maize) Sold in Katsina Central Market, Nigeria

Abstract

This study was carried out to isolate moulds and detect aflatoxin in maize sold in Katsina Central Market. A total of ten samples of maize were collected from five different vendors in the market and subjected to mould isolation, aflatoxin extraction, and characterization of the toxin type using Thin Layer Chromatography (TLC). Four fungal genera, namely Aspergillus, Penicillium, Fusarium, and Rhizopus species, were isolated from 7 (70%), 1 (10%), 3 (30%), and 7 (70%) of the samples, respectively. Aspergillus species were the predominant species isolated, with Aspergillus flavus occurring in 7 (70%) and Aspergillus niger in 6 (60%) of the total samples. Extraction of the toxin was carried out using methanol and water, while the type of toxin was determined using thin layer chromatography (TLC), where blue fluorescence on the TLC plates in 7 (70%) samples indicated the presence of aflatoxin B. Retention factor (RF) values, with a range of 0.40–0.60, were calculated using the standard formula. The research suggests proper harvesting, drying, storage, and public enlightenment to avoid contamination and consumption of maize grains infested by the number one carcinogenic toxin.