PROCESS OPTIMIZATION OF OIL EXPRESSION FROM WATERMELON (CITRULLUS LANATUS) SEEDS
Watermelon fruit contains large quantities of seeds and these seeds are under-utilized. It contains reasonable amount of oil (22%) which if expressed will serve as vegetable oil for human consumption or biodiesel for powering agricultural machines and boost the income of the farmers. The main objective of this research work is to study the interaction effect of operating parameters on the mechanical oil expression from the seed. The variables considered include applied pressure (85.00, 90.00, 95.00, 100.00 and 105.00 kN/mm2), roasting temperature (70.00, 80.00, 90.00, 100 and 110 °C) and moisture content (6.00, 8.00, 10.00, 12.00 and 14.00 %). A total sum of 20 batch experiments were carried out and the maximum oil yield was 13.49% (at corresponding moisture content of 6.00%, roasting temperature of 85.00oC and applied pressure of 105.00 kN/mm2 respectively) and minimum oil yield obtained was 9.41%.(at corresponding moisture content of 14.00%, roasting temperature 80 °C and applied pressure of 85.00 kN/mm2 respectively). While the optimum oil yield of 12.42% was obtained from the expression at corresponding moisture content of 6.00%, roasting temperature of 80.00ºC, and applied pressure of 105.00 kN/mm2. The result showed that the three independent variables had significant effect on oil yield and regression model equation was developed to predict the oil yield from watermelon seeds at known variables.