Effect of processing parameters on coconut oil expression efficiencies.

摘要

The effect of process parameters on oil expression efficiency from freshly dried coconut gratings was investigated. The range of parameters investigated were: pressing time, 4 and 8 min; particle size, fine (0.6-1.18 mm) and coarse (1.18-2.36 mm); pressure, 3-33 MPa; moisture content, 3%, 7%, 11% and 15%; and temperature, 30 degrees C, 60 degrees C and 90 degrees C. Results showed that 8 min of pressing and finer particles both led to significantly (P<0.05) higher oil expression efficiency. The pressure increase within the range 3-13 MPa led to significantly higher oil yields, with yields leveling off thereafter. The effect of pressure increase was highly associated with the moisture content of the gratings, and the optimum moisture content under low-pressure pressing was found to be 11%. A pressing temperature of 60 degrees C led to higher oil expression efficiency, whereas a further increase of temperature to 90 degrees C did not lead to a significant increase in oil yield..