Effect of Process Variables on Palm Oil Extraction Efficiency Using a Locally Fabricated Hydraulic Press in Ondo State

Palm oil extraction in rural South West Nigeria is predominantly carried out using traditional methods that result in significant oil losses and poor product quality. This study investigates the effect of selected process variables on extraction efficiency using a locally fabricated hydraulic press operated by smallholder processors in Owo Local Government Area, Ondo State. Fresh fruit bunches were sourced from three farms, sterilised, stripped, and digested at temperatures between 70 and 100 degrees Celsius. The influence of digestion temperature, press duration, press pressure, and moisture content of the press cake on oil extraction efficiency and free fatty acid content were examined using a full factorial experimental design. Oil extraction efficiency was calculated gravimetrically, and free fatty acid content was determined by titration. Results showed that digestion at 90 degrees Celsius, press pressure of 50 bar, and press duration of 20 minutes yielded maximum extraction efficiency of 87.3% with free fatty acid content within acceptable limits for edible grade oil. Moisture content of the digested mash had the most significant influence on extraction efficiency. Losses attributed to residual oil in press cake were estimated at 8 to 12%. Optimisation findings are directly applicable to improving the performance of existing hydraulic presses deployed across Ondo State oil palm cooperatives. Keywords: palm oil, hydraulic press, extraction efficiency, free fatty acid, Ondo State