DETERMINATION OF PHYSICOCHEMICAL PROPERTIES OF SELECTED VEGETABLE OILS IN MINNA

Abstract

The present study investigates the physicochemical properties of selected brands of vegetable oils (groundnut, soya bean oil, palm oil and palm kernel oil) sold in Minna, using standard procedure. The specific gravity of the oil ranged from 0.93±0.30 to 0.96±0.20. There was a significant difference in the relative densities of the oils studied. Natural palm oil has the highest relative density (1.42±0.26) while natural grand pure oil has the least (1.36±0.13). The refractive index varied from 1.35±0.05 to 1.45±0.35. The high refractive index of the oil samples showed that there was high number of carbon atoms in their fatty acids. The saponification values for oils investigated in this study ranged from 151.16±0.25 to 207.90±0.10 mgKOH/g. The iodine value ranged from 31.61±0.55 mgI2/g to 103.16±0.76 mgI2/g, which indicates that the oil samples contained appreciable level of unsaturated bonds. Palm oil has the highest acid value (1.13±0.21 mg NaOH/g) while the least value was found in Baron oil (0.42±0.03 mg NaOH/g). The acid values of the oil brands did not differ significantly. The peroxide values varied from 0.37±0.06 to 6.97±0.4 meq/kg. The values of all these parameters were within FAO recommended standard for edible oil. Thus indicating that, the sample oils under study are of good quality and suitable for consumption.