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

peer reviewedIn 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

Thermal and structural behavior of two lauric fats compared to AMF in bulk and oil-in-water emulsion states

In a previous study the thermal and polymorphic behavior of four different industrial lauric fats which are sold under the same commercial description, was compared (1). According to the findings the four fats were split in two groups based on the similarities found at polymorphic level. In the present paper two of these industrial lauric fats (F1 and F2, one from each group) were incorporated into oil -in -water emulsions. The objective of this study was to point out the differences in the crystallization and polymorphic behavior between bulk and emulsified fat. Moreover anhydrous milk fat (AMF) was used in the same way for comparison. For that purpose, the fats were investigated for their thermal and polymorphic behavior by differential scanning calorimetry (DSC) and X-ray diffraction (XRD), both in bulk and emulsified state. The DSC and X -Ray investigations made possible the observation of the differences in the crystallization behavior and kinetics that occurred for those fats in the bulk and emulsified state. 1. Anihouvi, P.P., C. Blecker, A. Dombree, S. Danthine, Comparative Study of Thermal and Structural Behavior of Four Industrial Lauric Fats, Food Bioprocess Technol. 6:3381-3391 (2013

La variabilité du profil de substitution de l'hydroxypropylcellulose affecte ses propriétés physico-chimiques

peer reviewedHydroxypropyl cellulose (HPC) is a water-soluble polymer with many applications in food, pharmaceutical, medical, or paints industries. Past studies have reported that differences in functionality can occur between products of similar pharmaceutical grades. Understanding the origin of these differences is a major challenge for the industry. In this work, the structure and physico-chemical properties of several HPC samples of the same commercial grade were studied. Structural analysis by NMR and enzymatic hydrolysis were performed to study molar substitution and distribution of substituents along the polymer chain respectively. Water-polymer interactions, surface properties as well as rheological and thermal behavior were characterized to tentatively correlate them with the structure, and gain new insights into the structure-function relationship of this polymer. The differences in structure revealed between the samples affect their properties. The unexpected behavior of one sample was attributed to a more heterogeneous substitution pattern, with the coexistence of highly and weakly substituted regions along the same polymer chain. The more block-like distribution of substituents has a great effect on the clouding behavior and surface tension reduction ability of the polymer