Curcumin, the bioactive compound found in turmeric, exhibits a wide range of health-promoting properties. However, its application in food and medicine is limited by its poor bioaccessibility. The purpose of this study was to investigate the potential for corn oil oleogels structured with three different concentrations of rice bran wax (RBW) (2%, 6%, and 10% w/w) to serve as a delivery system for curcumin to increase its bioaccessibility compared to an ungelled (0% RBW) control. Additionally, the physical properties of oleogels were characterized with and without curcumin to assess the impact of curcumin on oleogel physical properties. Various measures, including texture profile analysis (TPA), solid fat content (SFC), polarized light microscopy (PLM), differential scanning calorimetry (DSC), and x-ray diffraction (XRD) were used to characterize the oleogels. Moreover, an in vitro simulated digestion study was used to assess the bioaccessibility of curcumin in the oleogel systems. Data analysis revealed no significant differences in polymorphic or thermal properties between oleogels with and without curcumin; however, differences in microstructural properties were documented for oleogels with curcumin. No difference was observed in the SFC of ungelled and 2% RBW oleogel samples. Furthermore, oleogel hardness only differed at 10% RBW. After in vitro simulated digestion, oleogels prepared with 6% and 10% RBW significantly increased curcumin bioaccessibility relative to the ungelled control and 2% RBW oleogel. Results from this study provide insight into the potential utilization of RBW oleogels for delivering curcumin and other poorly water-soluble compounds in food, dietary supplement, pharmaceutical, and cosmetic industries.
