Encapsulation of Omega-3 Fatty Acids from Nigerian Freshwater Fish Oil for Food Fortification Applications

Omega-3 fatty acids, particularly eicosapentaenoic acid and docosahexaenoic acid, are essential nutrients with documented cardiovascular and neurodevelopmental benefits. Nigerian freshwater fish such as catfish and tilapia contain significant omega-3 fatty acids, but their incorporation into processed foods is limited by susceptibility to oxidative deterioration. This study extracts omega-3-rich oil from catfish (Clarias gariepinus) obtained from aquaculture farms in Ogun State, South West Nigeria, and evaluates microencapsulation using complex coacervation and spray drying for food fortification applications. Fish oil was extracted by wet rendering and characterised for fatty acid composition by gas chromatography-mass spectrometry and oxidative stability by rancimat analysis. Wall materials evaluated for complex coacervation include gelatin-gum arabic, whey protein-pectin, and sodium caseinate-maltodextrin systems. Microencapsulation efficiency, particle size, oxidative stability under accelerated conditions, and release properties under simulated gastrointestinal conditions were assessed. Results showed that the whey protein-pectin system achieved the highest encapsulation efficiency of 93 percent and the best oxidative stability, with the induction period extended threefold compared to unencapsulated oil. Particle size was 150 to 300 micrometres. Incorporation into biscuits at a level providing 150 mg omega-3 per serving did not significantly affect sensory quality. The study draws on recent omega-3 encapsulation literature and contributes to functional food fortification research with Nigerian fish oil sources. Keywords: omega-3, microencapsulation, catfish oil, food fortification, oxidative stability