COMPARATIVE STUDY OF OIL PROPERTIES EXTRACTED FROM AFRICAN PEAR PULP USING MECHANICAL AND SOLVENT METHOD
ABSTRACT
The research project is to compare the properties of African pear pulp and its oil using screw press i.e. mechanical method and solvent method using n-hexane. The pulp of African pear “Dacryodes Edulis” were evaluated for their oil yield for both methods. The pulp of African pear was dried by frying to a moisture content level of 19.53 %. Then the dried by frying sample was screw press using mechanical method and the cake was subjected to extraction by solvent extraction method using n-hexane. The oil extracted was analyzed for the Physical characteristics of the oil extracted. The oil is a liquid at room temperature, dark green in color, the odour is agreeable and not offensive, and it has a specific gravity of 0.867 for mechanical screw press and 0.809 for solvent extraction method which shows that it’s less dense than water. The specific gravity for mechanical method is low while that of solvent method , this value is close to those obtained from other research work. The oil has a viscosity of 1.011cp for mechanical method and 1.091cp at 100 .and the chemical properties i.e. (Acid value, saponification value, peroxide value, iodine value) etc. the values obtained are respectively 11.424gm/KOH/gm for mechanical method and 18.840gm/KOH/gm for solvent method, 227gm/KOH/g for mechanical method and 221gm/KOH/g for solvent method, 3.3 for mechanical method and 3.4 for solvent method ,33 for mechanical method and 34 for solvent method and Physical properties i.e. (Refractive index, specific gravity ,density viscosity ) which the values obtained are 4.3brix for mechanical method and 4.0brix for solvent method , 0.864 for mechanical method and 0.809 for solvent method ,867 for mechanical method and 809 for solvent method ,1.011 for mechanical method and 1.091 for solvent method , and the percentage oil yield for mechanical (screw press) content is 22.02% and solvent extraction content is 41.78%. This physico-chemical properties composition of this oil for method show that they have domestic and industrial potentials
