THE IMPACT OF EMULSIFICATION AND WHIPPING ON FAT CRYSTALLIZATION BEHAVIOR: A COMPARATIVE STUDY BETWEEN ANHYDROUS MILK FAT AND A LAURIC FAT

Abstract

In the present study, one commercial lauricfat (LF) and one anhydrous milk fat (AMF) were compared for their behavior in three different states: bulk, O/W emulsion and whipped cream. The objective of this work was to identify the crystallization and polymorphic behavior of the aforementioned fats, while pointing out the differences between the two fats, and for each of them, between the fat’s bulk, O/W emulsion and whipped cream state. For this purpose a combination of differential scanning calorimetry (DSC) stop&return, pulsed nuclear magnetic resonance (p-NMR) and powder X-Ray diffraction (XRD) was employed. In the bulk phase, during crystallization under quiescent conditions, the two fats show a distinct thermal and polymorphic behavior. In this regards, the AMF would require a lower supercooling degree or a longer crystallization time compared to LF which showed little/no evolution during the isothermal crystallization. The XRD measurement revealed a mix of α and β’ form for LF, all forms in a double chain lamellar structure (2L). Under the same conditions the bulk AMF was characterized by a 2Lα + 2Lβ’ and in addition compared to the lauric fat, a 3Lα form. The pointed differences exist between the two fats, mainly due to their chemical compositions. The emulsification/whipping did not affect the behavior of neither AMF nor LF. The lack of differences between bulk, O/W emulsion and whipped cream of the same fat upon DSC stop&return disclose the presence of heterogeneous nucleation in all three states. Regardless the complexity of fat chemical composition, throughout obtaining O/W food emulsion and/or structured creams the fat can be processed without altering its original properties.