Triglycerides obtained by dry fractionation of milk fat: 2. Thermal properties and polymorphic evolutions on heating

The crystallographic and thermal properties of milk fat and fractions were investigated on heating using the coupling of synchrotron X-ray diffraction with differential scanning calorimetry. We showed that re-crystallisations occurred during the heating of the stearin and the olein fractions with the formation of a β′ 2L (41.1–42.6 Å) structure and a β′ 3L (66 Å) structure, respectively. By creating a quantified solid–liquid phase behaviour versus temperature diagram, the amount of the solid and liquid phases and the relative proportion of each of the crystalline structures within the solid phase were determined.