Based on the type of vegetable, the different processes applied led to microstructures with different rheological properties. This study shows that particle size distribution, morphology and phase volume are important parameters to explain the complex relationship between rheology and microstructure for these types of systems.

Organogels based on edible oils and specific mixtures of phytosterols can serve as structured systems with a low saturated fat content. These low-SAFA organogels can be used also to create o/w emulsions. Little is known about the structures formed in these specific organogels and at the emulsion interface. We studied o/w organogels on different length scales to describe and understand their micro-structural features. Very basic processing conditions such as composition, temperature and storage time were taken into account. Two different types of structure were observed; at the smallest scale, long thin crystals are formed out of the oil phase into the continuous water phase. We propose that these are needle-like crystals. Next, tube-like structures are identified and can be visualized as tubular micelles. A model is proposed which fits the dimension (*7 nm) with the length scale of the molecular building blocks (TAGs and sterols). As edible fats from food products are enzymatically hydrolyzed in the gut prior to absorption, we also looked into the impact on the lipase reaction speed. Simple in vitro enzymatic hydrolysis experiments showed a slower enzymatic digestion. Organogel systems and emulsion made thereof have interesting food structuring properties with possible advantages in composition (low SAFA) and digestion speed.

Microstructure of dispersions of lamellar droplets carrying anchoring hydrophobically endcapped poly(sodium acrylate)s as novel steric stabilizers Kevelam, J; Martinucci, S.; Engberts, J.B.F.N.; Blokzijl, W.; van de Pas, J.C.; Blonk, H.; Versluis, P.; Visser, Antonie J.W.G. Copyright Other than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).Take-down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons the number of authors shown on this cover page is limited to 10 maximum. We have studied the influence of anchoring hydrophobically single-endcapped poly(sodium acrylate)s on the microstructure and colloidal stabilization of self-assembled lamellar droplets formed from a mixture of anionic and nonionic surfactants in concentrated aqueous electrolyte solutions. A fluorescently labeled hydrophobically endcapped poly(sodium acrylate) has been synthesized and characterized using timeresolved fluorescence spectroscopic techniques; it appears that the fluorophore has considerable freedom of internal rotation. Using this labeled poly(sodium acrylate), the presence of an adsorbed polymer layer bound to the surface of the droplets was imaged by confocal scanning laser microscopy, providing visual evidence that the droplets are sterically stabilized. Laser diffraction and refractive index measurements were employed to determine average particle sizes of the colloidal particles, and it was established that increasing the molecular weight of the hydrophilic (pendant) backbone at a constant (hydrophobic) anchor density, or increasing the concentration of polymer in the dispersion at constant molecular weight, results in a decrease of the average droplet size. This is in agreement with theoretical predictions that an increased lateral pressure in the adsorbed layer, due to a higher polymer segment density near the surface, is relieved by increasing the curvature of the lamellar droplets. Finally, the adsorption of hydrophobically endcapped polymers to lamellar droplets has been described in terms of a Freundlich isotherm, reflecting the degressive increase of the amount of polymer adsorbed onto the surface of the droplets with increasing polymer concentration. Again, an increase of lateral pressure with surface coverage is held responsible for this effect.

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Diffusion-driven water uptake in a substrate (imbibition) is a subject of great interest in the field of food technology. This is a particular challenge for rice grains that are preprocessed to accelerate the water uptake, i.e., to reduce the cooking time. Rice preprocessing disrupts the mesostructural order of starch and induces a microporous structure in the grains. The meso-and microstructural length scales have not been considered in joint approach until now. The (re)hydration of rice grains can be modeled by free (concentration-driven) diffusion or by water demand-driven diffusion. The latter is driven by the ceiling moisture content related to the extent of gelatinization of the rice substrate network. This network can be regarded as a fractal structure. As the spatial resolution of our models is limited, we choose to model the apparent water transport by a set of coupled partial differential equations (PDEs). Current models of water uptake are often limited to a single dimension, and the swelling of the substrate is not taken into account. In this article, we derive a set of PDEs to model water uptake in a three-dimensional (3D) inhomogeneous substrate for different types of water diffusion as well as the swelling of the substrate during water uptake. We will present simulation results for different 3D (macroscopic) structures and diffusion models and compare these results, qualitatively, with the experimental results acquired from magnetic resonance imaging.