Trace Elemental Characterization of Selected Edible Vegetable Oils

Abstract

Trace element content of edible vegetable oils is a basic criterion in the assessment of the quality of the oils with regard to freshness, keeping properties, storage and their influence on human nutrition and health. They are also known to have an effect on the rate of oil oxidation. In this study, the levels of 10 elements which include such essential metals as Ca, Mg, Na and K, trace elements such as Cu, Mn, Co and Ni and such toxic metals as Cd and Pb in8 varieties of edible vegetable oils (palm, palm kernel (P.K.O), sesame, soya bean, coconut, ground nut, olive and mustard) collected in Enugu were determined using the direct solvent method and a Buck Model 210VGPatomic absorption spectrophotometer. The concentrations of Ca, Na, K, Mg, Cu, Co, Mn, Ni, Pb and Cd were observed in the range of 0.69 - 0.23, 1.57- 0.48, 2.90 - 1.28, 1.30 - 1.05, 0.60 - 0.00, 1.12 - 0.51, 0.80 - 0.44, 0.00 - 0.00, 3.07 - 0.00, and 0.77- 0.55 mg/kg respectively. Ni was not detected in all the samples. The values for Pb and Cu were higher than the maximum values recommended by FAO/WHO and EU.