Camellia Oil Oleogels Structured with Walnut Protein–Chitosan Complexes: Preparation, Characterization, and Potential Applications

As a step towards the substitution of saturated fats with camellia oil in foods, a camellia oil-based oleogel was prepared using a walnut protein isolate-chitosan (WPI-CS) composite via an emulsion template method. The preparation process, structural characteristics, and stability of the oleogel were systematically analyzed. Our findings showed that varying the ratio of WPI-CS to camellia oil (CO) effectively regulated the emulsion particle size, zeta potential, and viscosity, thereby subsequently influencing the oil-holding capacity (OHC), rheological properties, and thermal stability of the oleogel. When the WPI-CS:CO ratio was 13:7, the oleogel exhibited superior performance, including relatively high OHC, improved rheological properties, and excellent thermal stability. In addition, the OHC of the oleogel varied significantly with temperature, and high oxidative stability was observed at WPI-CS ratios such as 13:7-10:10. Application tests in cake formulations demonstrated that the oleogel has potential as a partial butter replacement. This study provides a theoretical basis for the construction of WPI-based oleogels and offers new insights for the development of healthy fat substitutes.