Sweet potato, cocoyam, water yam, maize, millet, sorghum, and rice are major staple foods in Ghana. Flour from these roots and tubers and cereals are relatively cheaper, easy to produce and can be used in the manufacturing of wide range of products, including bread, cookies, meat pies, cake, chips and doughnut. However, due to the processing techniques used these flours may be contaminated with trace metals and aflatoxins. It was therefore necessary to determine the concentration of trace metal: As, Cu, Fe, Hg, Pb, Zn, and aflatoxin B_1, B_2, G_1, and G₂ in maize, sorghum, millet, rice, cocoyam, water yam and sweet potato flour samples used as composite flour for making bread and other pastries.

The trace metal concentration of essential metals: Cu, Fe and Zn in all the seven flour samples analyzed ranged from 0.03 ± 0.01 to 6.63 ± 0.02, 10.97 ± 0.01 to 201.40 ± 0.14, and 6.04 ± 0.03 to 34.36 ± 0.06 mg/Kg, respectively. The maximum concentrations of toxic metals: As, Hg and Pb determined in all the seven flour samples were < 0.01, < 0.01, and 0.05 ± 0.01 mg/Kg, respectively. Aflatoxin B_1, B_2, G_1, and G₂ were not detected in any of the samples.

The concentrations of As, Cu, Hg, Pb and Zn determined in all seven flour samples were below the WHO set limits and therefore pose no health threat whiles Fe concentration in some flour samples was above the WHO set limit. Aflatoxin B_1, B_2, G_1, and G₂ were not detected in all flour samples and hence pose no health threat.