Processed cheese as a polymer matrix composite: A particle toolkit for the replacement of milk fat with canola oil in processed cheese.

In this study, we show that the replacement of milk fat with canola oil in a model caseinate-based imitation cheese product to increase its nutritional value can be done by treating processed cheese as a particle filled gel network. Using microscopy, model imitation cheese products with different lipid phases were found to have similar microstructures where fat or oil appears as inert particle fillers in a continuous protein network. Using a texture profile analyzer, we show that the textural properties of model imitation cheese are dependent on the material properties of the inert filler. Addition of rigid particle fillers generally results in greater reinforcement of the matrix (i.e., increased hardness). The addition of oat fiber particles at 5% volume fraction to model cheese containing 51% milk fat and 49% canola oil resulted in a product with similar functionalities (i.e., hardness, oil stability, and meltability) as that of model cheese containing 100% milk fat. The current study therefore shows that the addition of edible non-fat particles for matrix reinforcement can be used as an alternative method for reducing saturated fats in foods while keeping other desirable properties of the product.

Structure and functionality of nanostructured triacylglycerol crystal networks.

In this review, recent advances in the characterization of the nanoscale structure of fat crystal networks are outlined. The effect of different factors on the properties of crystalline nanoplatelets (CNPs) is comprehensively described. These are discussed together with the observed changes in polymorphism and micro- or mesostructural properties so as to have a complete understanding of the influence of different internal and external factors on the material properties of fats. The relationship between the nanostructure and the material properties of fats (i.e., oil binding capacity and rheology) is also described. Characterization of the nanostructure of fats has provided a new dimension to the analysis of fat crystal networks and opportunities for nanoengineering that could result in innovations in the food industry with regards to processing and structuring fatty materials.

Formation of ß Polymorphs in Milk Fats with Large Differences in Triacylglycerol Profiles.

In this study, we characterized the polymorphism of milk fat (MF) with various TAG compositions during isothermal crystallization at 20 °C. TAG composition of MF from seven individual cows was determined using GC-FID and MALDI-TOF MS, and MF polymorphism was studied using X-ray diffraction. Results showed that TAG profile determines the polymorphic behavior of MF. Saturated TAG with carbon numbers 34-38 promoted the formation of α polymorphs, whereas unsaturated TAG with 52-54 promoted the formation of the ß polymorphs. Furthermore, MFs with unsaturated fatty acid profiles were increased in unsaturated TAG with 52-54 carbons. The presence of MF crystals in the ß polymorph has been controversial over the years as most authors mainly find MF crystals in the α and ß' form. In our work, we showed that the ß polymorph is formed in MF on the basis of its TAG composition.