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.

Edible oleogels have emerged as promising alternatives to conventional solid fats. They convert liquid oils into semi-solid structures while reducing saturated and trans fatty acid intake. Despite rapid growth in this field, their performance is not governed by a single factor but by coupled effects of oil composition, oleogelator properties, intermolecular interactions, and processing history. In recent years, substantial progress has been achieved in understanding the formation mechanisms, structural regulation strategies, and food applications of oleogels. This review systematically summarizes the key factors influencing oleogel formation and performance, including oil phase composition, gelator type and concentration, molecular interactions, and processing parameters. Emerging structural modulation approaches, such as multi-component oleogelators, hybrid biopolymer systems, and advanced processing technologies, are critically discussed with respect to their effects on crystallization behavior, network architecture, rheological properties, thermal stability, and oil-binding capacity. Particular emphasis is placed on the hierarchical structure–function relationships linking molecular assembly and network organization to macroscopic functionality, digestibility, and bioactive compound delivery. Recent applications of oleogels in bakery products, meat analogs, dairy alternatives, confectionery products, and frying systems are also reviewed. Finally, current challenges and future opportunities related to next-generation oleogelators, hierarchical structural regulation, intelligent responsive systems, and industrial-scale manufacturing are discussed. This review provides a comprehensive framework for understanding the structural engineering of edible oleogels and offers insights into the rational design of healthier and more functional lipid-based food systems.