Effects of practices of maize farmers and traders in Ghana on contamination of maize by aflatoxins: Case study of Ejura-Sekyeredumase Municipality

Contamination of maize by aflatoxins is of major concern to governments and the international community because high degrees of aflatoxin in food render the food unsafe for human consumption. The disposal of such foods also constitutes an economic loss in food production. This paper reports the findings of a study conducted during the 2013 minor maize farming season in Ejura-Sekyeredumase Municipality in the Ashanti region, and in Agbobloshie market in the Greater Accra Region of Ghana. The study was to investigate management practices employed at the market level and on farms by maize traders and smallholder farmers, respectively, and their impact on aflatoxin contamination. Purposive sampling was used to select 150 farmers from maize farming communities across 10 cluster zones based on geographical location of farms within the municipality. Maize traders were also selected from a market close to maize farms and a market close to consumers for the study. In all, 30 traders were randomly selected from each market. Maize samples were collected from both markets and selected farms to determine the presence and level of aflatoxins using the Vicam Aflatest immunoaffinity column method. The study revealed that, farmers and traders adopt practices that expose maize grains to aflatoxin contamination. These include: use of farmer-saved seed stock as planting material; delayed harvesting, heaping harvested maize cobs on the field; planting by broadcasting method, use of hand dipping and teeth cracking method to determine dryness of maize, use of wooden stalls with no proper ventilation for maize storage at market centres and temporal storage in the open using tarpaulin resulting in heat build-up and moisture re-absorption. Types of aflatoxin determined from sampled maize grains were G2, G1, B2 and B1. Grains from the farms showed below detection limit at 1 ppb of aflatoxins. However total values of 50.234, 70.102 and 30.943 ng/g were, respectively obtained from three composite samples taken from Ejura market. A similar occurrence was observed at Agbobloshie market, where higher levels of 677.480, 101.748 and 4831.942 ng/g were detected in composite samples analysed. All respondents had no knowledge of aflatoxin contamination and it causes. Moreover, 63% of traders from both markets believed that, consuming contaminated maize have no health implications for consumers as food products from maize are normally cooked before consumption. In conclusion, the study reveals that, practices of farmers and traders has direct effect on maize quality. It was noted that, aflatoxin contamination of maize is likely to increase from the farm through markets and ultimately compromise the health of consumers. Farmers and traders need to be encouraged to adopt best practices in maize production and marketing to ensure food safety of the final consumer. Education on aflatoxin and its health implications must also be given the necessary attention.