Impact of rice bran wax composition and oleogelation conditions on the structural stability of sunflower oil-based oleogels

The growing demand for healthier ingredients has driven research toward innovative systems, such as oleogels, which can provide nutritional benefits without compromising food texture and mouthfeel. Among various structuring agents, rice bran wax (RBX) is a promising candidate for creating three-dimensional networks in liquid vegetable oils. However, the functional success of these systems is heavily dependent on wax composition and processing conditions. This study investigates the impact of RBX compositional profile and oleogelation conditions on the structural stability of sunflower oil-based oleogels. A laboratory-extracted RBX (obtained via an optimised isolation protocol) was compared with two commercial alternatives to evaluate the possible influence of interfering compounds on microstructural assembly. Results show that the compositional profile of the laboratory-purified RBX promotes highly cohesive inter-crystalline interactions, yielding a robust and continuous solid matrix even at low concentration (1%wt) depending on the process conditions. Conversely, the application of mechanical stirring during the oleogelation phase was found to hinder the development of a continuous solid network, promoting the formation of aggregates that led to notable oil separation during storage. Under these dynamic conditions, minor components present in commercial waxes appeared to partially mitigate this aggregation, indicating a clear trade-off between compositional homogeneity and resilience against mechanical stress. These findings demonstrate that high-performance oleogels can be achieved by optimising both wax isolation protocols and environmental conditions during oleogelation. This research provides fundamental insights for future research aimed at incorporating chemically uniform RBX oleogels into complex food matrices as a sustainable alternative to saturated fats, contributing to the development of improved lipid-based food products