Extraction And Characterization Of Castor Seed Oil

Abstract

The castor seeds used for this work were obtained in a market at Esa-Oke town in the western part of Osun State of Nigeria. The seeds were prepared for use by removing the endocarp, sun-drying for five days and milled to flour. A soxhlet extraction was used for the extraction of the oil and the solvent used was hexane . The oil was recovered by simple distillation. The residual oil obtained was investigated for physicochemical parameters and fatty acid composition. The result shows that : moisture content (0.300± 0.01%), specific gravity (0.948± 0.02), refractive index @30C (1.792± 0.01) ,fire point (256.000± 1.20C), flash point (225.000 ± 2.10 C), smoke point (215.000 ± 1.00 C), viscosity @ 28 C (0.425 ± 0.12), pH (5.800 ± 0.00), congealing temperature (-18.000 ± 1.50 C), turbidity (5.000 ± 1.00 C). Others were free fatty acid (7.400 ±0.07% oleic acid), acid value (14.800± 0.14 % oleic acid), saponification value (178.000± 0.42mgKOH/g oil), peroxide value (158.640 ± 2.20Meq/Kg), iodine value (58.390 ± 0.71wijs), The crude oil sample was determined according to AOAC,(1984), They are within acceptable standard. The yield of 48% makes the commercialisation of the seed in Nigeria possible and profitable. Also, the result of the analysis confirms the oil to be of good quality and can find application in food industry as food additives as well as industrial purposes.