Hazelnut Oil Oleogels Structured With Rice Bran Wax: Textural, Rheological and In Vitro Digestion Properties

ABSTRACT

In this study, hazelnut oil was structured with rice bran wax (RBW) at different concentrations (6%, 8%, and 10% w/w) to investigate the effects of wax content on physicochemical properties, in vitro digestion behavior, and 3‐monochloropropane‐1,2‐diol (3‐MCPD) bioaccessibility. The oleogels were characterized for thermal, textural, and rheological properties, followed by in vitro digestion and assessment of 3‐MCPD bioaccessibility. All formulations exhibited high oil binding capacity (OBC) (> 85%). The enthalpy of melting increased significantly with wax content from 6.59 to 12.6 J/g, indicating that greater energy was required for melting at higher RBW concentrations. Higher RBW concentrations increased hardness (2.5–26.7 N) and storage modulus, reflecting stronger gel structures. Free fatty acid release was inversely correlated with wax concentration, decreasing from 70.5% in the 6% RBW oleogel to 52% in the 10% RBW oleogel. 3‐MCPD bioaccessibility decreased significantly from 66.6% to 45.2% as RBW concentration increased. Overall, RBW effectively structured hazelnut oil into stable oleogels with enhanced mechanical strength, but at the expense of reduced lipid digestibility. These results highlight the potential of RBW–structured hazelnut oil oleogels as fat replacement systems and demonstrate that increasing RBW concentration can be used to modulate lipid digestion and the bioaccessibility of oil‐soluble compounds.

Practical Applications : The results of this research highlight the potential of rice bran wax–structured hazelnut oil oleogels as alternatives to conventional solid fats in food formulations. Their high hardness and elastic network make them suitable for applications in bakery products, spreads, and confectionery, where texture and stability are critical. Importantly, the reduced lipid digestibility observed suggests an additional role for these systems in designing foods with controlled fat release, which may be beneficial for calorie reduction and the development of lower‐energy food products or for lowering the bioaccessibility of unwanted compounds such as contaminants. The use of rice bran wax, a by‐product of rice processing, further supports sustainability and valorization of agricultural side‐streams, in line with circular economy principles. Thus, these oleogels offer dual functionality: improving food structure while serving as vehicles to modulate lipid digestion and bioaccessibility, making them promising candidates for health‐oriented and sustainable product development.