Differential Thermal Analysis of the Melting and Solidification of Milk Fat

Differential thermal analysis (I)TA) heating curves were recorded for milk fat cooled slowly, rapidly, and tempered; for the same fat from which 7% of HMG fraction was removed, and the same fat after randomization of' the fatty acids on the glycerides. Thermal treatments led to differences in DTA curves that could be explained by the formation of nfixed c~}'stals of different glyceride groups. DTA cooling curves of milk fat, milk fat from which 7% of HMG was removed, and randomized nfilk fat are presented. DTA curves of conventionally churned and continuously made butters indicate that the latter type contains more mixed crystals, which may be an explanation for its different physical properties. Tributyrin was found to be a more satisfactory reference compound for DTA than was dioctylphthalate.