Oil expression from Jatropha seeds using a screw press expeller

Experiments were conducted to determine the effects of moisture content, cooking temperature, and cooking time on the yield of oil mechanically expressed from Jatropha seed using a screw press expeller. A maximum oil recovery of 73.14% was obtained when Jatropha seeds were conditioned to a dry basis (db) moisture level of 9.69% and cooked at 110 °C for 10 min. Screw press oil recovery, residual oil, pressing rate, and oil sediment content were measured at different moisture contents for uncooked and cooked seed. At optimum processing conditions, oil recovery from cooked seed was 7% higher than that of uncooked seed. Pressing rate decreased from 30.92 to 29.5 kgh−1 and 31.38 to 29.87 kgh−1 for cooked and uncooked seeds, respectively, where as sediment content increased from 4.27 to 7.86% and 4.02 to 5.27%, respectively, as moisture content decreased. Oil expressed under the processing conditions investigated was of acceptable quality.