Rheological and Physicochemical Characterization of Structured Chia Oil: A Novel Approach Using a Low-Content Shellac...

Vegetable oils structured with natural wax blends have attracted increasing interest due to their tunable crystallization and gelling behavior. This study evaluated the structuring of chia oil (ChO) using low concentrations (1-5%) of a shellac wax (SW) and beeswax (BW) blend in a 1:1 ratio, focusing on physicochemical, viscoelastic, and thixotropic properties. ChO structured with 1% SW/BW formed a weak network with high oil loss, whereas concentrations of 3-5% formed denser networks, resulting in OBC values of 75.6-88.4% and firmness values of 16.9-55.1 g. Structuring with 5% SW/BW significantly reduced peroxide values (p < 0.05), indicating a reduction in oxidative deterioration after oleogelation, while concentrations of 1-3% had no significant effect (p > 0.05). Although induction periods were slightly extended in structured samples, differences across oleogelant concentrations were not statistically significant (p > 0.05). Rheological analysis revealed that 3-5% SW/BW-structured ChO exhibited semisolid gel behavior, characterized by enhanced deformation resistance and thermal stability. Thixotropic recovery tests revealed that structural recovery improved as the deformation amplitude decreased within the linear viscoelastic range, suggesting that thixotropic behavior was influenced by oleogelant concentration. These findings demonstrate the potential of SW/BW-structured ChO as fat alternatives in lipid-based foods that require mechanical resilience, structural recovery, and enhanced oxidative stability, even at low wax levels.