Determination of Oil Content and Physicochemical Properties of Oil Extracted from Niger Seed Oil Grown in Gamo Gofa, Southern Ethiopia

The Niger seed oil was collected from gamo-gofa, southern part of Ethiopia for oil extraction. The collected seed were oven dried and crushed in to powder by mortar and pestle. A soxhlet and maceration extractions were used for extraction of the oil. The solvents used for both extractions were n-hexane and ethyl acetate. The main reason two different types of solvents and two different type of extraction methods used in this project were to check which type of solvent and extraction method were effective for extraction of oil from Niger seed. From both extraction methods the extracted oil was separated from the solvents by simple distillation. The oil content and the physico-chemical parameters of the oil were determined and an oil content of 23.45% and 21.35% were obtained by maceration and 33.02% and 22.7% by soxhlet extraction method from n-hexane and ethyl acetate respectively. The physico-chemical parameters of the seed and oil were determined and the result shows that moisture content of the seed was (8.3%) and acid value of the oil (1.7391), saponification value (6.0308), Kinematic viscosity (0.561 m²/s), Density of oil (0.9788 g/ml) and Specific gravity of (0.9947). From the result obtained we conclude that n-hexane is an effective solvent and soxhlet extraction is an effective extraction method for extraction of oil from Niger seed.