Abstract
Margarine and fat spread contain typical water-in-oil emulsions, including semi-solid fats, as continuous oil phases. The application of palm oil, one of the most promising transfat alternatives, for semi-solid fats is increasing. However, granular crystals often occur in palm-oil-based solid fats and cause deterioration. In this study, we carried out differential scanning calorimetry (DSC), optical microscopy, and X-ray diffraction (XRD) experiments on granular crystals in margarine. Microstructures of the granular crystal were precisely observed with a synchrotron radiation small-angle XRD technique and polarization microscopy with a compensator. We analyzed the microstructures and formation processes of granular crystals in relation to the fractional crystallization of the β form of 1,3-dipalmitoyl-2-oleoyl-sn-glycerol promoted by crystallization and transformation of tripalmitin and tristearin fractions.
