Physicochemical Properties of Some Vegetable Seed Oils and Their Applications

The physicochemical properties of oils were discussed, and as a case study, extracted from three
locally available plant seeds in Nigeria namely: Alchomea cordiforlia, Cyperus esculentum and Irvingia
gabonensis using n-Hexane and their properties determined. The results of the analysis revealed that
their % yield were 37.00, 27.50 and 33.00 for A. cordiforlia, C. esculentum and I. gabonensis
respectively. Their odour was non-offensive and their colours were reddish, light yellow and milky
white for A. cordifolia, C. esculentum and I. gabonensis respectively, making them bright and
attractive. The specific gravity of the oils at 25°c was 0.91, 0.94 and 0.92 for A. cordiforlia, C.
esculentum and I. gabonensis respectively. Their flash points in °C were also 155, 159 and 229
respectively, indicating that I. gabonensis is the most thermally stable oil and suitable for frying. The
chemical properties for A. cordiforlia, C.esculentum, and I. gabonensis respectively were as follows:
Acid values in mgKOH/g were 24.67, 5.33 and 3.73. Peroxide values in mEqKg-1 were 7.26, 9.86 and
2.96. Saponification values in mgKOH/g were 162.13, 179.52 and 238.43. Iodine values in g/100g
were 24.62, 11.68 and 3.38. These results indicate that the three seeds are viable sources of oil
based on their % yield. They are good for both domestic and industrial use based on their acid,
saponification and iodine values. Their properties in most cases compete favorably with palm kernel
oil (PKO) which is currently being used for many domestic and industrial purposes in Nigeria
especially for the making of paints, soap, cosmetics, lubricant and varnishes.