Rheological properties of ethyl cellulose-monoglyceride-candelilla wax oleogel vis-a-vis edible shortenings.

The gelation process, elasticity, and mechanical recovery after shear were studied in mixed oleogels of ethylcellulose (EC), monoglycerides (MG), and candelilla wax (CW). EC oleogels produced without MG showed grainy texture due to incomplete dissolution of crystalline fractions of raw EC in the vegetable oil (150 °C). These fractions were eliminated by dissolving the raw EC/MG mixture in ethanol, evaporating the solvent, dispersing, and dissolving the solid residue in the vegetable oil (150 °C) prior gelation. The EC polymeric network, and MG, and CW crystals had a positive interaction on the elasticity of mixed oleogels. Mixed oleogels produced under static conditions showed a 100 % of elasticity recovery after shearing, a phenomenon associated with an EC interchain hydrogen bonding mediated by hydroxyl groups of MGs. This tentatively resulted from the formation of junction zones of the type EC-[MG]n-EC. The rheological behavior of these olegels was remarkably close to that of commercial shortenings.

Structuration, elastic properties scaling, and mechanical reversibility of candelilla wax oleogels with and without emulsifiers.

The crystal network development, elastic properties scaling behavior, and mechanical reversibility of candelilla wax (CW) oleogels with and without emulsifiers were studied. Saturated monoglycerides (MG) and polyglycerol polyricinoleate (PGPR) were added at 1 or 2 times the critical micelle concentration. Although the micelles of both emulsifiers act as nucleation sites for the mixture of aliphatic acids and alcohols of CW, they did not affect the oleogel's thermodynamic stability. It was established that the crystal network of CW consists of at least two types of crystals, one rich in n-hentriacontane and other rich in aliphatic acids. Both crystals species contributed significantly to the oleogel elasticity. The elastic properties scaling behavior of CW oleogels fitted the fractal model within the weak-link regime. The setting temperature and added emulsifier modified the crystal network fractal dimension. During shearing, oleogels had massive breaking of junction zones, causing the loss of fractality in the crystal network, which in turn decreased the system's elasticity.

Water-in-oil organogel based emulsions as a tool for increasing bioaccessibility and cell permeability of poorly water-soluble nutraceuticals.

The use of organogels in food and pharmaceutical sciences has several technical problems related with restricted diffusion of the drugs and lack of a proper gelator molecule. These features are important into the new product design. An alternative to improve technological properties in organogels is the use of emulsions. However, there is a lack of knowledge about the behavior on bioaccessibility and permeability of bioactives loaded into organogel-based emulsions. The objective of the present experimental work was to study the physical properties of organogel-based emulsions made with vegetable oil loaded with three different bioactives (betulin, curcumin and quercetin) and the influence on their bioaccessibility. Organogels were made of canola or coconut oils and myverol as gelator (10% w/w). Water-in-oil emulsions (at 5, 10 and 12.5 wt% of water content) were prepared by mixing the melted proper organogel and water (80 °C) under high shear conditions (20,000 rpm). Micrographs, rheological tests (amplitude, frequency, temperature sweeps and creep-compliance measurements), DSC and particle size analysis were performed to samples. In vitro digestion (oral, gastric and intestinal phase), lipolysis assays, bioaccessibility and permeability tests by cell culture of Caco-2 were made. Organogels of coconut oil have shown poor emulsification properties.

Phase behavior, structure and rheology of candelilla wax/fully hydrogenated soybean oil mixtures with and without vegetable oil.

Vegetable oil organogelation is one of the most promising strategies to eliminate trans fatty acids in plastic fats. Organogels prepared with edible wax are stable at refrigerator and room temperature. Some functional properties (i.e., texture) of wax organogels can be improved by adding saturated triacylglycerols. Mixtures of fully hydrogenated soybean oil (FH) and candelilla wax (CW) were studied with and without the addition of high oleic safflower oil (HOSFO). Crystallization and melting behavior, X-ray diffraction, and crystalline microstructure of the mixtures were analyzed. The elastic modulus (G'), and the structural recovery after shear of the organogels were also assessed. Mixtures without HOSFO formed solid dispersions of CW and FH crystals, where up to ~10% CW crystals were incorporated into the FH crystal lattice. The vegetable oil solutions of FH/CW mixtures crystallized from the melt, developed mixed crystal networks composed of FH crystals in the ß polymorph and CW in an orthorhombic subcell packing. As the systems crystallized in the most stable polymorph, only minor microstructural changes were shown along 28days of storage at 25°C. CW and FH crystals showed a synergistic effect on the elasticity of organogels. This was attributed to the large number FH crystals nucleated on the surface of CW crystals. The structural recovery after shear was superior for mixed organogels composed of CW platelets and grainy FH crystals compared to that of CW organogels. A recovery of up to 65.7% the G' of gels formed under static conditions was observed upon shearing.