High Internal Phase Emulsions (HIPEs) offer a novel strategy for structuring liquid oils into semi-solid systems with improved stability and functionality. This study aimed to synthesize HIPE-based emulsion gels from sardine oil by-products and evaluate their potential as colloidal lipid carriers to enrich omega-3 fatty acids and enhance texture in freshwater fish surimi, which inherently has low lipid content and weak gel strength. HIPE gels were formulated using sodium caseinate (SC) and carrageenan (CAR) as emulsifiers at oil phase fractions of 30%, 50%, and 70%. The 70% HIPE formulation exhibited superior stability, showing minimal oiling-off (1.76%) and the smallest mean droplet size (32.82 µm). Confocal laser scanning microscopy (CLSM) revealed a continuous and homogeneous microstructure. Rheological analysis demonstrated solid-like viscoelastic properties (G′ > G″), confirming the formation of a strong internal network. When incorporated into surimi at 15% (w/w), the HIPE gel significantly improved texture, with hardness of 2469.16 ± 0.94 N, springiness of 83.88 ± 0.27%, cohesiveness of 0.60, and protein content of 16.18%. These results suggest that marine oil-based HIPE gels can function as stable omega-3 delivery and texturizing systems, enhancing both nutritional value and structural integrity in freshwater fish products. The integration of food-grade hydrocolloids within HIPE systems provides a sustainable and functional lipid structuring strategy for next-generation protein-based foods.

Keyword: hydrogel, Hydrocolloid stabilization, oleogel, Omega-3 delivery system