Encapsulation of fish oil by complex coacervation and freeze drying with modified starch aid

This work developed a combination method between gelatin-sodium hexametaphosphate (SHMP) complex coacervation and freeze-drying with aid of starch sodium octenyl succinate (SSOS) for the preparation of fish oil -encapsulated powders. The results suggested the preparation and properties of the powders were dependent on the used gelatins. Porcine skin gelatin (PSG), bovine skin gelatin (BSG), and fish gelatin (FG) had good gelling properties and could successfully prepare the complex coacervates and powders. The solution pH and SHMP: gelatin mass ratio were critical parameters for the preparation of the complex coacervates. SSOS was a good freeze-drying aid to increase the encapsulation efficiency (EE). The obtained fish oil-encapsulated powders had similar fish oil loading capacity values (24.0-26.2%) and different fish oil EE values: PSG (98.4%) > FG (96.4%) > BSG (95.2%). After the in vitro digestion process, the fish oil-encapsulated powders were digested and free fatty acid release percentage was dependent on gelatin source: PSG (55.5%) > FG (34.1%) > BSG (27.0%). This work provided useful information for the potential use of gelatin, fish oil, and SSOS in the development of powder foods.

Automated summary

This study developed a method combining gelatin-SHMP complex coacervation and freeze-drying with the aid of SSOS for the preparation of fish oil-encapsulated powders. The choice of gelatin type and the pH of the solution were critical factors in preparing the complex coacervates. SSOS was found to improve the encapsulation efficiency. The fish oil-encapsulated powders had similar loading capacity but different encapsulation efficiency values, and their digestion and release of free fatty acids depended on the gelatin source. This work provides valuable information for the development of powder foods using gelatin, fish oil, and SSOS.