Comparative Analysis of Dietary Silica in Vigna subterranean (Bambara Nut) and Arachis hypogeal (Ground Nut or Peanut)

Nutritional awareness has been longtime challenge in Nigeria even among literate populace. Many Nigerians preferred food that has characteristic taste to nutritional value. A comparative study to estimate the amount of silica in bambara nut (BN) and groundnut (GN) was carried out in order to create awareness on the preferred grain to be consumed, due to nutritional health benefits of silica. The pulverized sample of each cotyledon was carbonized at 350°C for 30 minutes using muffle furnace to obtain bambara nut ash (BNA) and ground nut ash (GNA), respectively. To produce silica, 10 g ash of each sample was digested separately with NaOH solution to form sodium trioxosiicate. The solution was treated with HCl solution to yield silica at pH adjusted to 7.0. The yield of 2.29% and 9.66%, for BN and GN, respectively, was obtained. Characterization using FT-IR technique has indicated the presence of silanol (Si-OH) and siloxane (Si-O-Si) functional groups in the spectra of the two samples. In addition, Scanning Electron Microscope (SEM) analysis respectively revealed the morphological structure of SiO₂extracted from BNA and GNA to be amorphous. Thus, the form in which cells of the body can assimilate.