Solid-liquid extraction of oils of African elemi’s fruit

Abstract

African elemi (Canarium schweinfurthii) contains oil in its fruit’s pulp and kernel. Solvent extraction of these oils using n-hexane has been investigated in this work to obtain some process parameters. This was done at different temperature over a period of time with varying solvent to feed (solid) mass ratios. Oil yield and extraction efficiency were observed to increase with time, temperature and materials ratio but in different fashions. The kinetics of the oils’ extraction was found to be adequately described by Peleg equation and a variant of it. At 30^oC, kernel oil recorded the highest saturated extraction yield (C_s) with 7.5g solvent/g solid while no peak was observed for pulp oil extraction using 1 to 10g solvent/g solid. Kernel oil gave the highest saturated (maximum) yield (45.93g/100g solid) but pulp oil gave the highest initial extraction rate (B_o=3.5868 g/L.min) and fastest time constant (τ_o=9.84 min). Free fatty acid content of the extracted oils was observed to increase with leaching temperature while iodine value reduced with it. This phenomenon was more pronounced with kernel oil.