The objectives of this work are to design a small scale screw press for soya bean oil extraction; to fabricate the components of the machine based on the design specifications and; to test the oil press after fabrication and assembly of the components. This machine was aimed at easing the pain, stress, intensive labour, and time consumption encountered in the existing soya bean oil pressing processes. The basic features of the soya bean oil extracting machine are the frame, electric motor, pressing drum, oil outlet, cake outlet, hopper, pulleys, transmission belts and bearings. In operation, the gradually built-up pressure along the screw drum travel conveys, crushes, grinds, presses and squeezes oil out of the prepared soya bean into the oil outlet via the oil channel. The residual cake from where the oil is extracted is extruded out of the cake outlet in form of flakes. Analysis of variance showed that cylinder speed made significant effects at p≤0.05 on the parameter evaluated and the separation of means using F-LSD showed significant difference on the parameter evaluated. The quality of extracted soya bean oil was also analysed. The oil was evaluated as follows: free fatty acid value 2.5 %, saponification value 191 mgKOH/g, iodine value 128 I2 /100g, peroxide 4.68 meq/kg, total viable count (TVC) 0.2 x 101 CFU/mL and total coliforms count 0.0 x 101 CFU/mL. These values fall within the acceptable standard values. Based on the characteristics of the oil, it could be suitable for applications in pharmaceutical and food industries.
