OPTIMUM PROCESSING PARAMETERS FOR COCONUT OIL EXPRESSION

Abstract

Coconut oil yield was found to be dependent on the following processing parameters: post heating moisture content, applied pressure, pressure duration, heating time and temperature to which the samples were subjected using hydraulic uniaxial compression.

The highest coconut oil yield obtained was 51.9% at optimum condition. This yield corresponds to an expression efficiency of 81.2% of the total coconut oil content which represented 63.9% by weight of the copra (dried coconut flesh). The highest oil yield was obtained at an expression pressure of 25MPa when samples were conditioned to an initial moisture content of 11.3% w. b. and heated at 120ºC for 15min to obtain a post heating moisture of 7.13% w. b.

       Increases in oil yield were recorded for increases in applied pressure but this tended to level off between pressures of 20 and 25MPa. At all levels of pressure used, applied pressure duration of 10min was found to be optimum for high oil yield.

       The specific gravity of coconut oil produced in this study was found to be 0.95 and the viscosity was 960 pa.s.  for the  measured  temperature of 30ºC and refractive index of 1.45. The saponification value, iodine value and free fatty acid values measured were 259, 9.6 and 27 respectively.