Co-encapsulation of fish oil and curcumin using complex coacervation followed by freeze-drying

Nutrients co-encapsulation is a significant research focus in functional foods. This study developed a method to co-encapsulate fish oil and curcumin (Cur) using bovine bone gelatin (BBG)-chitosan (CS) complex coacervation, followed by freeze-drying with maltodextrin (MD) as a drying aid. The results confirmed that the successful encapsulation of fish oil/Cur droplets in the powder particles. As the MD/BBG mass ratios increased (0–8), several trends were observed for the powders: the oil loading capacity decreased progressively (17.7%–2.7%), oil encapsulation yields increased and then decreased (54.1%–27.9%), oil encapsulation efficiencies exponentially increased (75.6%–92.9%), Cur loading capacities exponentially decreased (0.82%–0.24%), Cur encapsulation yields exponentially increased (63.7%–85.9%), Cur encapsulation efficiencies linearly decreased (79.8%–73.4%), and peroxide values during the oxidative stability process logistically increased (19.5–44.5 mmol/kg oil at 1 h). During simulated small intestinal digestion, an MD/BBG mass ratio of 5 resulted in the highest percentage (92.8%) among all ratios tested (0–8). These results suggested fish oil can act as an effective carrier for Cur in functional powders, and that miscible nutrients can be co-encapsulated within complex coacervates. This work provided an efficient strategy for developing raw materials with co-encapsulated nutrients for functional foods and contributed to understanding the underlying mechanism of the multi-nutrient co-encapsulation.