Effects of Conjugated Linoleic Acid on Oleogel Structure and Oxidative Stability

Oleogels have attracted attention as healthier alternatives to traditional solid fats. Conjugated linoleic acid (CLA) is valued for its bioactive effects; however, integrating CLA into oleogels and ensuring their stability remains challenging. Beeswax (BW) is a widely used organogelator, yet CLA-enriched oleogels with BW have not been previously explored. This study aimed to prepare and characterize CLA-enriched oleogels using beeswax, focusing on their physical, thermal, rheological, and oxidative stability properties.

CLA was chemically synthesized from linoleic acid and incorporated into sunflower oil at concentrations of 25% and 50%. BW was used as the oleogelator at 2%, 3%, and 4%. Oleogels were prepared via heating and controlled cooling. Physicochemical analyses included oil binding capacity, gel stability, color, rheology, texture, X-ray diffraction (XRD), and thermo-oxidative stability. Storage stability was monitored over 120 days at 25°C by measuring peroxide value (PV) and thiobarbituric acid reactive substances (TBARS).

Oleogels exhibited strong oil-binding capacity and viscoelastic behavior. Increasing BW concentration enhanced structural firmness, while higher CLA content significantly improved oxidative stability but reduced thermal resistance (Tonset and Tmax). XRD analysis revealed predominantly α- and β′-type crystals originating from BW. CLA-enriched oleogels showed significantly lower PV and TBARS values during storage compared to controls, particularly in formulations with moderate CLA levels and ≥3% BW.

CLA’s antioxidant properties contributed positively to oleogel oxidative stability; however, excessive CLA concentrations adversely affected thermal resistance and gel homogeneity. BW effectively structured the gels and facilitated CLA integration. The interaction between CLA and BW influenced crystal formation, firmness, and storage stability. Study limitations include the use of a single oil type and absence of sensory evaluation or thermal cooking simulations.

CLA-enriched BW oleogels represent a promising alternative to traditional solid fats by combining biofunctional benefits with mechanical and oxidative stability at room temperature. Their incorporation into food systems may reduce dependence on unhealthy fats while extending shelf life. Future research should investigate sensory properties, culinary performance, and broader food applications.