Ferritin Cage–Alginate Oligosaccharide-Stabilized Emulsion for Co-Carriage and Protection of Zinc Ion and Hydrophobic Molecule

Ferritin, a natural cage-like protein, can be applied as a nanomaterial to encapsulate and deliver bioactive ingredients, while challenges remain when using ferritin to deliver multiple bioactive ingredients. In this study, a ferritin–zinc ion–alginate oligosaccharide (AOS) core–shell complex (FZA) and hydrophobic astaxanthin (AST) were applied as the water and oil phase to prepare oil-in-water emulsions simultaneously containing mineral element and hydrophobic AST. The ferritin works as a multicompartment carrier to encapsulate the Zn2+ ions and bind with the AOS. This emulsion exhibited smaller particle size and higher apparent viscosity, elastic modulus, and anti-delamination stability. After heat treatment, natural light irradiation, and ultraviolet irradiation, the retention rates of AST in FZA-stabilized emulsion were increased by 23.09%, 18.25%, and 19.24%, respectively, compared with AST dissolved in oil. The release rate of AST in FZA-stabilized emulsion was increased by 26.97% compared with that dissolved in oil in vitro digestion simulation, and release rate of Zn2+ ions in FZA-stabilized emulsion improved by 20.38% relative to the control. This study provides experimental evidence for the emulsion stabilized by the AOS and ferritin multi-interface, which achieves dual co-delivery and protection of mineral and hydrophobic molecules.