Optimization and Characterization of Crosslinked Chitosan-Based Oleogels Based on Mechanical Properties of Conventional Solid Fats

Industrial <i>trans</i> and saturated fatty acids, which are key components of solid fats used in food products, should be replaced with unsaturated fatty acids from vegetable oils to reduce cardiovascular risk. However, unsaturated oils lack the structured networks required to replicate the technological properties of solid fats. Oleogelation, especially using polymer-based networks, offers a promising solution. This study optimized chitosan-based oleogels crosslinked with vanillin to mimic the texture of butter, partially hydrogenated fat, margarine, and palm fat while minimizing oil loss. Oleogels were prepared via the emulsion-template method and optimized through a central composite design combined with a desirability function, evaluating the effects of chitosan, vanillin, Tween^® 60 concentrations, oil type (canola or soybean), and storage temperature (4 °C or 25 °C). Optimized oleogels were characterized for their rheological and microstructural properties. Chitosan concentration primarily governed oil loss, hardness, and adhesiveness of oleogels, independent of the oil phase and storage temperature. However, storage at 4 °C reduced oil loss but increased the hardness and adhesiveness compared to storage at 25 °C. The highest desirability scores (0.72 to 0.94) were achieved in soybean oil oleogels with 0.99% chitosan, 0.24-0.32% vanillin, and 0.17-0.18% Tween^® 60, closely mimicking the texture of butter and margarine. These oleogels demonstrated stronger networks, enhanced gel strength, and elasticity, positioning them as viable alternatives to conventional solid fats.