Combination of internal structuring and external coating in an oleogel-based delivery system for fish oil stabilization.

In this study, we created oleogel-based formulations featuring varying degrees of beeswax for internal structure and whey protein isolate (WPI) as external coating to improve the oxidative stability of fish oil. Oleogel was characterized by rheological analysis to access gelation behavior, and morphology was visualized using electron microscopy. It was found that the WPI-coated oleogel displayed strong physical stability during storage. The oxidative assay demonstrated that WPI-coated oleogel had the best protection against fish oil oxidation under both thermal treatment and ultraviolet-C radiation. The oxidation of fish oil was inhibited by 2-3 fold, compared to its unencapsulated form. This stability was attributed to the modulation of beeswax and WPI on the micropolarity and microviscosity of the formulation, as evidenced by pyrene fluorescence measurement. Our approach combining internal structuring and external coating may contribute to the development of oleogel system for efficient delivery of lipophilic bioactive components.