keywords: Dehulling, maize, sorghum, millets, iron, zinc, magnesium
Cereals are major staple foods in Nigeria, and are rich sources of nutrients especially when used as whole grains. However, to improve palatability and organoleptic qualities, most grains undergo further processing to yield better products. These processing include dehulling, dehusking, milling, etc. which may alter the nutritional composition of the resultant products to varying degrees. But, the outer parts of the kernels, especially the aleurone layer and the germ, tend to be richer in minerals when compared to the starch endosperm. The present study investigated the effect of dehulling on the levels of micronutrients (Fe, Zn and Mg) of grains (sorghum, millet and maize). The results revealed a clear negative effect of dehulling on the concentrations of Fe, Zn and Mg. In all the grains studied, Fe, Zn and Mg decreased significantly (P < 0.05) in the experimental samples when compared to the control samples. In real terms, this represented 40- 44% decrease in the levels of Fe, Zn and Mg in sorghum, 3- 24% in maize and 2-7% in millet respectively. Although, dehulling of grains is carried out to also reduce the levels of antinutrients, it inevitably affects negatively the levels of desirable nutrients which are mostly located on the outer parts of the grains.