Development and Physicochemical Characterization of Rice Bran Oil Oleogels Structured with Beeswax, Carnauba Wax, and...

Oleogels have emerged as promising alternatives to conventional solid fats by structuring liquid oils without increasing trans or saturated fat levels. This study therefore aimed to develop rice bran oil (RBO)-based oleogels using beeswax (BW), carnauba wax (CW), and their combinations, and to compare their physicochemical properties with commercial margarine. Thirteen formulations with varying wax concentrations were prepared and analyzed using differential scanning calorimetry, microscopy, rheology, texture profile analysis, oil binding capacity, slip melting point, peroxide value, color analysis, and fatty acid profiling. Our results demonstrated that the thermal behavior of the oleogels is dependent on the type and concentration of the wax, with CW oleogels exhibiting higher crystallization and melting temperatures than BW, while hybrid systems displayed intermediate and synergistic properties. Distinct crystal morphologies were observed, with BW forming needle-like and CW forming spherulitic structures, while the hybrids created interconnected networks. All samples exhibited shear-thinning and gel-like behavior, with greater viscosity and gel strength observed at increasing wax concentrations. The hybrid oleogels achieved hardness comparable to higher CW levels and approached margarine texture, while maintaining high oil binding capacity (>94%). The RBO oleogels contained higher unsaturated fatty acids but showed lower oxidative stability than margarine. Overall, BW-CW hybrid oleogels demonstrated strong potential as healthier, solid fat alternatives with improved structural and thermal characteristics.