Encapsulation of bioactive salmon protein hydrolysates with chitosan-coated liposomes

• Antidiabetic salmon peptides were encapsulated using high pressure homogenisation.
• Encapsulation involved electrostatic coating of liposomes with chitosan.
• Chitosan delayed simulated gasto-intestinal digestion.
• Chitosan reduced freeze-dehydration and freeze-thaw processes.

A nano-encapsulation strategy for a chitosan-coated liposomal oral delivery system using milk fat globule membrane (MFGM) phospholipids for the entrapment of antidiabetic peptides prepared from Atlantic salmon (Salmo salar) protein hydrolysates (SPH) was developed. The size, zeta potential, entrapment efficiency, stability during freeze-drying freeze thawing, and long-term storage abilities of the nano-capsules were investigated as a function of concentrations of phospholipid and chitosan coating material. Chitosan coating greatly improved the stability of liposomes. The maximum encapsulation efficiency (71.3%) and physical stability were achieved with 10% MFGM phospholipid and 0.4% chitosan. Chitosan coating significantly prolonged the release of SPH in simulated biological fluids. In conclusion, liposomes with “optimal” chitosan coating-concentration show great promise as a potential new delivery system for protein hydrolysates.