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.

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.