Abstract

Five samples of selected brands of vegetable oils sold in Ilorin metropolis were investigated for some physicochemical parameters. Relative density, flash point, smoke point, crackle test, cold test and viscosity were determined for each sample. Also, the saponification, acids, ester and iodine values, as well as the fatty acid profile for each sample were investigated. Viscosity of the different brands of oils at varying temperature were significantly different (P < 0.05) for A356, A360 and A374, while there was no significant difference between A364 and A370. There were significant differences (P < 0.05) in the relative density, flash, and smoke points of samples A374 and A364 compared to the others (A360, A370 and A356) which were not significantly different from one another. All the vegetable oil samples passed the crackle test, but all failed the cold test. There were no significant differences (P > 0.05) in the chemical properties investigated for all the vegetable oil samples. The fatty acid profile indicated the presence of oleic and linoleic acids in all the samples while palmitic and stearic acids were present in only two of the samples, and myristic acid was found in only one of the samples. However, all the samples met the set standards for edible oils by regulatory bodies.

Key words: Vegetable oils, physicochemical parameters, fatty acids profile, NIS standards.