Fortification of Milk with Omega-3 Fatty Acids Using Novel Bioactive-Carrier Hollow Solid Lipid Micro- and Nanoparticles for Improved Omega-3 Stability and Bioaccessibility

Preparing foods and beverages fortified with fish oil is challenging because fish oil oxidizes easily and is not soluble in water. Novel hollow solid lipid micro- and nanoparticles (HoSoLiP) were developed by a simple and green process using supercritical CO2 technology to fortify milk with fish oil and to increase the oxidative stability and bioaccessibility of fish oil. Spherical free-flowing fish oil-loaded HoSoLiP (6.9 μm) with a fish oil loading efficiency of 92.8% were formed. Omega-3-enriched milk was developed by incorporating the fish oil-loaded HoSoLiP into skim milk. The HoSoLiP-incorporated EPA and DHA in the fortified milk were stable for 3 weeks, whereas the free fish oil-incorporated milk was stable for only 1 week. The in vitro digestion study showed that HoSoLiP significantly improved the bioaccessibility of the omega-3 fatty acids (EPA and DHA) in fish oil loaded in the HoSoLiP (40.4%) compared to the milk fortified with free fish oil (27.4%) (p < 0.05). This approach generates a novel powdered fish oil formulation that is loaded into solid lipid particles and allows the incorporation of fish oil into beverages in a simple and clean way while improving its stability and potential health benefits.