Predicting melting characteristics of vegetable oils from fatty acid composition

The enthalpy and melting characteristics (onset melting temperature, endset melting temperature, peak melting temperature and enthalpy of melting) of 12 vegetable oils were experimentally determined within a temperature range of -60 and 25 degrees C by means of a differential scanning calorimeter. Data obtained showed that vegetable oils melt over a wide temperature range (19-44 degrees C). The enthalpy required to increase the temperature of the vegetable oil samples from -60 to 25 degrees C was between 241.1 and 325.7 kJ/kg. Results from fatty acid composition indicate that the amount of the monounsaturated or polyunsaturated is highly correlated (R-2>0.91) with the onset melting temperature, peak melting temperature and enthalpy of melting for the 12 vegetable oil samples. Poor correlation (R-2<0.27) was obtained between the melting characteristics and the amount of saturated or unsaturated fatty acid. A linear equation was therefore used to relate each of the melting characteristics of a vegetable oil sample to the amount of monounsaturated or polyunsaturated fatty acid. The models developed are valuable for predicting material behavior and for modeling processing operations for vegetable oils. (C) 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.