Crystallization Kinetics and Mechanical Properties of Nougat Creme Model Fats

Oil mobility in sucrose-in-oil dispersions as a function of particle morphology and BET surface

Solid particles in dispersions, for example sucrose, can reduce the mobility of liquid oils, potentially through sorption or physical entrapment. So far, little is known about the mechanisms and influencing factors behind oil immobilization. Fatty acid composition of oils and the sucrose characteristics (particle size, morphology, BET surface) are thought to affect oil immobilization in sucrose-in-oil dispersions. For this purpose, dispersions were prepared using four refined oils (coconut, peanut, rapeseed and sunflower oil) and four sucroses (powdered sucrose, granular fine and coarse sucrose and cotton candy). The oils varied in their fatty acid composition, viscosity, and diffusion coefficient, while the sucrose samples differed in their BET surface, particle size, and morphology. To investigate the influence of these properties on oil immobilization, the sucrose-in-oil dispersions were examined across different length scales using oil binding capacity, flow behavior, viscosity and wettability (macroscopic scale), as well as oil diffusion (molecular scale). Oil immobilization in sucrose-in-oil dispersions was affected stronger by the sucrose properties, especially their morphology and BET surface, than by the oil properties. On a macroscopic level, cotton candy showed the highest oil immobilization, followed by powdered sucrose. On a molecular level, oil diffusion was hindered most by powdered sucrose, while the geometric hindrance was smallest in dispersions with cotton candy.

Crystal network structure and stability of beeswax-based oleogels with different polyunsaturated fatty acid oils

The effect of different types of oils including camellia oil (CLO), sunflower oil (SFO), corn oil (CO) and linseed oil (LO) on the formation, crystal network structure and mechanical properties of 4%wt beeswax (BW) in oleogel was investigated. BW oleogels containing oils with higher contents of polyunsaturated fatty acids gelled first (1%wt), especially LO with higher contents of linolenic acid rather than CLO with higher contents of monounsaturated fatty acids. In comparison, oils with higher polyunsaturated fatty acid contents exhibited higher D_b with more extensive microstructure at different cooling rates, which was related to shorter nucleation induction time of crystal and higher crystallinity. Stronger van der Waals forces were observed in oleogels with higher polyunsaturated fatty acid contents especially for LO oleogel. Rheology also showed that LO oleogel with higher content of linolenic acid had higher crystallinity and lower crystal melting interfacial tension, resulting in the formation of a more stable network structure.

Pre-Crystallization of Nougat by Seeding with Cocoa Butter Crystals Enhances the Bloom Stability of Nougat Pralines

Fat bloom is an outstanding quality defect especially in filled chocolate, which usually comprises oils of different origins and with different physical properties. Dark chocolate pralines filled with nougat contain a significant amount of hazelnut oil in their center and have been reported as being notably susceptible to oil migration. The current study was designed to test the assumption that a targeted crystallization of nougat with cocoa butter seed crystals is an appropriate technological tool to reduce filling oil transfer to the outside of the praline and, hence, to counteract chocolate shell weakening and the development of fat bloom. For this purpose, the hardness of nougat/chocolate layer models and the thermal properties of chocolate on top of nougat were analyzed during storage at 23 °C for up to 84 days. Pronounced differences between layer models with seeded nougat and with control nougat that was traditionally tempered were observed. The facts that chocolate hardness increased rather than decreased during storage, that the cocoa butter melting peak was shifted towards a lower temperature, and that the hazelnut oil content in the chocolate was reduced can be taken as explicit indicators for the contribution of seeded nougat to the fat bloom stability of filled chocolate.

Whipping properties and stability of whipping cream: The impact of fatty acid composition and crystallization properties

In this study, five fats (hydrogenated palm kernel oil, HPKO-A and HPKO-B; refined vegetable oils, RVO-A and RVO-B; transesterification oil, TO) were used to prepare whipping creams. HPKO-A and RVO-A which rich in lauric and myristic acids facilitated the formation of small crystals and dense crystal network, while higher stearic acid content of HPKO-B formed large spherical crystals. The richness in palmitic acid (RVO-B and TO) and oleic acid (TO) led to the formation of weak crystal network. Higher partial coalescence was correlated to higher collision frequency of fat globules and crystal connection, therefore, the overruns, firmness and stability of creams prepared by HPKO-A and RVO-A were higher than those of HPKO-B and RVO-B. The least stability of cream prepared by TO was related to the weak crystal networks. In summary, higher lauric and myristic acids content resulted in dense crystal networks, promoting partial coalescence and improving the cream quality.