Quantitative Analysis of Selenium in Staple Foodstuffs from Kanam Local Government Area, North-Central Nigeria

Abstract

Background: Although selenium was, for decades, considered toxic, many animal diseases has been found to respond to selenium. Selenium is, therefore, an essential trace element. Selenium is essential for human nutrition where it is a constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection. Selenium concentrations in plantbased foods vary widely by geographic location. This research was aimed at determining the amount of selenium in the local foodstuffs from Kanam Local Government Area in north-central Nigeria. Methods: Staple foodstuffs were selected across all the sections of the research area. Samples were homogenized in a ceramic mortar to obtain homogeneous samples with particle size > 300μm. These were digested using a diluted oxidant mixture containing 1 ml deionised H2O + 0.5 ml double-distilled HNO3. Selenium content was determined using the inductively coupled-mass spectrophotometry technique. Data obtained were analysed using the student’s t-test and results were presented as means and standard deviations. A probability level of p < 0.05 was considered statistically significant. Results: All the foodstuffs contained quantities of selenium high enough to meet the recommended daily allowance for all categories. Grain varied widely in their selenium content with white sorghum containing the lowest (6.16±3.97 μg/g) and red sorghum containing the highest (14.19±7.22 μg/g) followed by cowpea (13.05±8.79 μg/g). Conclusion: These values suggest that a diet well balanced in other nutrients is probably also nutritionally adequate with regard to selenium, although possible effects of cooking, processing, geographical variation and biological availability remain to be investigated.