Predicting the melting points and the enthalpies of fusion of saturated triglycerides by a group contribution method

Knowledge of the melting point and the enthalpy of fusion of triglycerides is necessary for the determination of solid–liquid phase equilibria of triglyceride mixtures or the production of fat-containing products. It is therefore very useful to have predictive models for these properties. Triglycerides can crystallize into three different polymorphic forms which are α (hexagonal), β′ (orthorhombic) and β (triclinic). A group contribution method (GC-method) has been developed for predicting the melting point and the enthalpy of fusion for each polymorphic form of the saturated triglycerides, which have an even number of carbon atoms (between 10 and 22) in each acyl group. The GC-method is based on the fact that a triglyceride can be described as consisting of two terminal acyl groups and one median acyl group. Thus, the parameters in the GC-method describe next to which terminal acyl groups the median acyl group is located, the GC-method takes into account the position of the acyl groups in the triglyceride and the class which the triglyceride belongs to. The GC-method predicts both the melting point and the enthalpy of fusion better than the existing models.