Aflatoxin management in Northern Ghana: Current prevalence and priority strategies in maize (Zea mays L)

The production and utilization of maize have increased tremendously across all regions of Ghana in recent times. However, aflatoxin (AF) contamination in grain maize has remained a critical food safety concern. The study was conducted in 6 districts in the Upper East and Upper West regions of Ghana to assess farmers’ knowledge on AF, and determine AF levels under farmer storage conditions. A total of 240 respondents from 24 communities were covered using a structured questionnaire, and 240 maize samples were obtained for AF analysis. All the samples were collected within 2 to 6 weeks after harvest for AF analysis using the Indirect Enzyme Linked Immunosorbent Assay method. Overall, 78% of the respondents were aware of AF although majority (68.1%) did not perceive AF as a major food safety issue. Aflatoxin prevalence ranged from 0.011 to 308 ppb with wide variations occurring within and across communities and districts. Though no clear pattern was established, AF prevalence in Garu-Tempane and Wa-West districts was marginally higher compared to counterpart districts. Grain samples from Nabdam district showed the least AF levels with all samples recording safe limits of <4 ppb. Overall, 78.8, 92.9 and 95.4% of the samples recorded safe limits of <4, <20 and <30 ppb, respectively. There is need to scale up proven pre-and-post-harvest technologies to the mainly small-holder growers to keep AF within safe limits. The Food and Drugs Board, the main food regulatory agency in Ghana, should be strengthened to conduct periodic testing for AF in grain markets in addition to food safety education.