Use of High-Intensity Ultrasound to Change the Physical Properties of Oleogels and Emulsion Gels

The objective of this work was to evaluate the effect of high-intensity ultrasound (HIU) on the physical properties of a soft oleogel (2% of candelilla wax, 2% of monoacylglycerol, and 2% of hardfat) and of water-in-oil (W/O) emulsion gels (EG) with various amounts of water (0%, 5%, and 25%). Physical properties of these systems such as thermoresistance, microstructure, melting profile, hardness, rheology, and oil loss were measured. When HIU was applied to the oleogel for 3 min using a 3.2 mm-diameter tip at an amplitude of vibration of 216 μm, a reduction in crystal size and crystal area (P < 0.05) was observed with an increase in hardness and no change in G′ nor in oil loss compared to the nonsonicated oleogel. Other sonication conditions (lower power levels, shorter durations, and bigger tips) tested in this study reduced the hardness and elasticity of the sample and increased oil loss. When HIU (3.2 mm-diameter tip, 216 μm, 3 min) was used in emulsions, harder and more elastic (P < 0.05) samples were obtained only in the samples with 25% water. This study shows that the texture of oleogels and EG with 25% of water can be improved by using HIU. The impact of these results is that the fat content of an EG can be reduced by 25% by adding water and HIU can be used to recover the structure lost due to water addition.     

Effect of the addition of hardfats on the physical properties of cocoa butter

Fully hydrogenated oils, also known as hardfats, are currently employed in a limited number of applications in the food and chemical industries. The use of these compounds has been proposed for the improvement or standardization of the physical properties of lipid systems, showing great potential for use in the production of chocolate, confectionery, and similar products. This work evaluated the addition of different hardfats on the physicochemical properties of cocoa butter (CB). Fully hydrogenated oils with significantly different chemical composition, obtained from palm kernel oil (FHPKO), palm oil (FHPO), cottonseed oil (FHCO), soybean oil (FHSO), and crambe oil (FHCrO), were evaluated for their fatty acid and triacylglycerol compositions. Blends of CB/hardfats, at concentrations of 1, 3, and 5% w/w were studied by determining the melting point, solid fat profiles, microstructure, and consistency. Hardfats FHPO, FHCO, FHSO e FHCrO proved to be effective additives to modulate the physical properties of CB. Major changes on the physical properties of CB were performed by the FHSO. FHPKO was found unsatisfactory as a modifier of the CB. Practical applications : The use of hardfats as crystallization additives in products containing CB is here recommended for technological adjustments of CB formulations in relation to attributes like heat resistance and hardness, often necessary when commercialized in regions of warm climates or with large variation in temperature. The hardfats may act as potential modulators of CB crystallization, aiming to obtain higher quality products and significant cost reduction of industrial processing.