ABSTRACT

Aflatoxins are natural toxigenic metabolites frequently found in millet and cereal products. Aspergillus species are mainly responsible for Aflatoxin build-up and contamination of millet products. The main objective of this study was to detect aflatoxin-producing moulds in millet grains commonly sold in Ndoru Market, Umuahia, Abia State. Four (4) millet samples were bought from  four (4) different sales point in Ndoru market from which eight (8) organisms were isolated using spread plate technique and belong to 2 genera and 4 species; Aspergillus niger, Aspergillus sp., Penicillium sp., Penicillium sp. The fungal population in millet products were enumerated and characterized using cultural and biochemical techniques.  The percentage of occurrence is; A. niger  was found in (37%), Aspergillus sp. (25%), Penicillium sp. (25%), Penicillium sp. (12.5%). However the highest prevalence of occurrence was seen in A. niger. Aflatoxin production by isolated fungi was subsequently evaluated using the thin layer chromatography technique and viewed under UV light. Two (2) fungal isolates (Aspergillus niger, Aspergillus sp.) of the Aspergillus genera produced green fluorescence as detected in the culture filtrates while the remaining two (2) isolates (Penicillium sp.) of the Penicillium genera produced no fluorescence. The green fluorescent colouration emitted under UV light which indicates the ability to produce aflatoxin, by aflatoxigenic strains was not observed for any of the tested non aflatoxigenic isolates. The findings from this study suggest that millet products obtained from the two(2) out of the four (4) different sales point are contaminated by aflatoxigenic fungi responsible for producing aflatoxin which could be unsafe as food or feed ingredients and it is recommended to use varieties resistant to toxigenic fungi.