Temperature effects on the extraction of rubber and melon seed oils

Oils were extracted from the seeds of rubber [Hevea brasiliensis (Kunth) Muell. Arg.] and melon (Colocynthis vulgaris Schrad) using different solvents at varying temperatures. The objective was to determine temperature coefficients (n) for enhanced oil removal and the enthalpy changes accompanying the extraction process. Values of n, obtained from the slopes of the plots of the natural logarithm of equilibrium oil yield vs T/10, were on the order of 1.10, showing that oil, yield increased by a factor of about 1.10 for every 10° rise in temperature. Also, n values were used to predict oil yields at other temperatures by knowing the oil yield at a given temperature. Enthalpy changes (ΔH) in the extraction of both oils were determined using the Arrhenius equation. The ΔH values obtained were in the range of 4–13.5 kJ mol−1, indicating the physical nature of oil extraction by a solvent.