Complex coacervation of dealkaline lignin with three different skin gelatins to encapsulate fish oil

The gelatin-anionic polysaccharide complex coacervation system represents a promising platform for developing oil powders. Herein, the complex coacervation of dealkaline lignin (DAL) with three types of skin gelatins (Bovine skin gelatin, BSG; porcine skin gelatin, PSG; cold water fish skin gelatin, CFSG) was explored for fish oil encapsulation. At optimal pH conditions, the particle sizes of the fish oil@gelatin-DAL complex coacervates were comparable (100-μm scale) across all three gelatin types. The resulting oil powders exhibited production yields of 58.7%–75.1%, loading capacities of 35.5%–44.5%, encapsulation efficiencies of 5.08%–8.66%, maximum peroxide values of 130.0–212.3 mmol/kg oil under 63 °C, and accumulative free fatty acid released percentages (49.3%–85.8%) in the in vitro digestion process. The differences were associated with the molecular interaction of gelatins with fish oil/DAL. All results suggested that DAL is a promising material to prepare oil powders in functional foods if low encapsulation efficiency is solved.