Distribution of Aspergillus flavus and aflatoxin accumulation in stored maize grains across three agro-ecologies in Ghana

Authors: DADZIE, M. - University Of Ghana; OPPONG, A. - Crop Research Institute - Ghana; OFORI, K. - University Of Ghana; ELEBLU, J. - University Of Ghana; IFIE, E. - University Of Ghana; BLAY, E. - University Of Ghana; OBENG-BIO, E. - University Of Ghana; APPIAH-KUBI, Z. - Crop Research Institute - Ghana; Warburton, Marilyn

Submitted to: Food Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/17/2019
Publication Date: 4/26/2019
Citation: Dadzie, M.A., Oppong, A., Ofori, K., Eleblu, J., Ifie, E.B., Blay, E., Obeng-Bio, E., Appiah-Kubi, Z., Warburton, M.L. 2019. Distribution of Aspergillus flavus and aflatoxin accumulation in stored maize grains across three agro-ecologies in Ghana. Food Control. 104:91-98. https://doi.org/10.1016/j.foodcont.2019.04.035.
DOI: https://doi.org/10.1016/j.foodcont.2019.04.035

Interpretive Summary: Fungal mycotoxins are important contaminants of agricultural commodities that pose serious concerns to producers, consumers and exporters. Aflatoxin is a carcinogenic metabolite produced by the fungi Aspergillus flavus and A. parasiticus. A. flavus and other mold species living in the soil contaminates several crops including maize where consumption of the toxin causes enormous health and socioeconomic costs to humans. Ghana lacks regulatory infrastructure for monitoring fungal contamination and detection of aflatoxin in grains prior to market. Therefore, this study assessed the extent of A. flavus contamination together with other mold on maize and total aflatoxin accumulation among stored maize grains across 34 towns and villages in 2016. A. flavus, was identified in over half the grains sampled across Fumesua, Wenchi, Ejura and Akomadan and total aflatoxin levels were above safe limits in many of these cases. These dangerous upper limits demand urgent attention in the area of aflatoxin resistance breeding in maize to help address the aflatoxin menace in Ghana.

Technical Abstract: Aflatoxins are carcinogenic secondary metabolites produced mainly by two species of Aspergillus fungi, (A. flavus and A. parasiticus). The toxin contaminates maize grains during the developmental stage as well as in storage. Grains with contamination levels above 20 ng/g are usually destroyed in the USA while the European Union and Japan allow 2–4 ng/g and nil respectively. Ghana lacks regulatory infrastructure for monitoring fungal contamination and detection of aflatoxin in grains prior to market. Therefore, this study assessed the extent of A. flavus contamination together with other mould on maize and total aflatoxin accumulation among stored maize grains across 34 towns and villages under three agro-ecologies in Ghana during the minor crop season of 2015–2016. A. flavus, was identified as the most predominant contaminant and recorded average percentage contamination of 56.7%, 30.6%, 53.5% and 45.6% on grains sampled across four communities (Fumesua, Wenchi, Ejura and Akomadan), respectively. Total aflatoxins recorded in the samples per community were in the range of below limit of detection (LOD) to 692 ng/g, 23 ng/g,945 ng/g and 112 ng/g for Fumesua, Wenchi, Ejura and Akomadan, respectively. These dangerous upper limits demand urgent attention in the area of aflatoxin resistance breeding in maize to help address the aflatoxin menace in Ghana.