Comparative study on crystallization behaviors of physical blend- and interesterified blend-based special fats

Crystallization behavior of special fats has a crucial influence on their physical properties. A comparative study was carried out on the crystallization characteristics of physical blend- and interesterified blend-based fast-frozen special fats (PBSF and IBSF). The content of trisaturated TAGs (SSS) decreased from 27.3% for PBSF to 12.5% for IBSF. At 0-45 °C, the SFC of PBSF and IBSF varied from 60.2% to 16.3% and from 53.1% to 2.9%, respectively. XRD results indicated that PBSF and IBSF had β′ and β crystals with double chain length structures, but IBSF had more β′ crystal content. Isothermal and non-isothermal crystallization kinetics studied by pNMR and DSC revealed that the nucleation and growth mechanism of PBSF and IBSF was different during crystallization. For IBSF, there were a large amount of spherical crystals with small size present in the crystal network. However, rod-like crystals with big size were distributed throughout the crystal network of PBSF.