MILK-FAT AND ITS FRACTIONS

Physical properties of whole anhydrous milk fat (AMF) and its fraction s have been studied by differential scanning calorimetry (DSC) and X-r ay diffraction as a function of temperature (XRDT). Several successive dry fractionations of both winter and summer AMF allowed to separate 32 fractions which have been analysed for compositions. Triacylglycero l (TG) compositions have been related to thermal and structural behavi ours of the 32 fractions obtained by combined DSC and XRDT studied as a function of their thermal treatment. It allowed to show that the num erous TG of AMF self-organise into three main crystal families charact erised by different melting domains which have been described in terms of TG composition, thermal properties and structures. These studies s howed a large solubility of monounsaturated TG in trisaturated long-ch ain TG and a relative immiscibility of the three TG families into each other. The influence of technological parameters such as cooling rate s, homogenisation, tempering, on thermal, structural and rheological p roperties of AMF and some of its fractions mixtures has also been stud ied at the pilot scale thanks to a series of Surface-Scraped Heat Exch angers and homogeniser, as a function of their blending. This first pa per give on overview of the scientific results of this study prior to their full publication.