Impact of rice bran wax purity 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 purity and processing conditions. This study investigates the impact of RBX purity and oleogelation conditions on the structural stability of sunflower oil-based oleogels. A purified 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 reduced quantity of impurities in the laboratory-purified RBX allowed for a more cohesive crystalline matrix, yielding enhanced stability even at low concentration (1 %wt) under static gelation conditions. Furthermore, 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 significant oil leakage during storage. These findings demonstrate that high-performance oleogels can be achieved by optimizing both wax isolation protocols and environmental conditions during oleogelation. This research supports the potential for incorporating high-purity RBX oleogels into complex food matrices as a sustainable alternative to saturated fats, contributing to the development of improved lipid-based food products