Estimation of the Levels of Fe in Wheat and Maize Flour Milled using Commercial Milling Machine and A Home Blender

Abstract

Milling devices are among the most commonly used in our indigenous markets and homes and variety of elements such as Cu, Ni, Zn, Pb, Ti, Co, Cr, Al, Si, and Fe are used in their manufacture and fabrication. Often times they are present as alloys. With prolonged processing, these metals are gradually introduced as contaminants in the food being processed. Wheat and maize were selected for this study due to their wide usage as sources of protein and carbohydrate in Nigeria and Africa in general. The samples were cleaned by picking out sand, stones and other impurities and ground using the commercial milling machine and a home blender and were digested with HNO3 and HClO4 in the ratio of 4:1 and analyzed using AAS. Average Fe concentration values for both wheat and maize samples milled with commercial milling machine is 13.53 mg/kg and 26.79 mg/kg respectively while samples milled with the home blender gave concentration values of 4.00 mg/kg and 2.64 mg/kg for wheat and maize respectively. The high concentration of Fe in ground maize and wheat milled using the commercial milling machine could be attributed to the abrasive friction of the grinding disc as the grains come in contact with it during grinding resulting in its chipping off into the milled sample. It is therefore recommended that the commercial milling machine be redesigned with the incorporation of a permanent magnet to minimize or totally eliminate the introduction of Fe fillings into the ground grains and other foodstuffs. 

Keywords: Commercial milling machine, wheat, maize, contaminants, home blender, grinding