Evidence of the effect of pre and postharvest practices on aflatoxin contamination in the Forest and Savannah ecozones of Ghana

Food contamination by aflatoxins is a global concern due to their adverse effects on food security, trade, and health. This study contributes to the evidence on the connection between pre and postharvest practices of maize farmers and the levels of aflatoxin contamination, based on a survey of 400 farmers across Forest and Savannah zones in Ghana. The survey involving a semi-structured questionnaire was conducted between September 2019 and March 2020. Information on preharvest practices such as weed control, fertilizer application, and irrigation; and postharvest practices such as drying, shelling, storage, and pest control among others were explored by the questionnaire. A multistage sampling process was employed to determine the sample size of four hundred respondents. One kg of maize was randomly sampled from the farmers for aflatoxin analysis. The results showed that the least aflatoxin type found in the maize sample was Aflatoxin G2 (0.207 μg/kg), while the highest was Afltoxin B1 (9.618 μg/kg). The Savannah zone recorded a lower contamination level of 11.63 μg/kg than the Forest zone of 23.53 μg/kg. Aflatoxin G1 and Aflatoxin G2 were less prevalent among the samples than Aflatoxins B1 and B2. The contamination levels in both zones exceeded the maximum limits, set by Codex, and EU at 10 μg/kg, and 4 μg/kg respectively. Only the Savannah zone contamination level met the maximum limit of contamination of Ghana which is set at 15 μg/kg. About 73% of farmers who demonstrated awareness of aflatoxin contamination had their produce within the maximum limit of Ghana, CODEX, and the EU. Preharvest practices such as fertilizer application, hoeing, and chemical weed control lowered aflatoxin contamination in both zones. The results showed that awareness creation and adoption of pre and postharvest interventions are vital in reducing aflatoxin contamination in the two ecozones.