Controlled preparation of fish oil powders via complex coacervation and genipin crosslinking

The application of fish oil is limited by its unpleasant fishy flavour, sensitivity to environments (e.g., oxygen, light, and heat), and poor water solubility. The complex coacervation-based encapsulation of fish oil in powders is a promising method to improve the behavior of fish oil in food science and engineering. Controlled preparation of fish oil powders has become an important topic in improving their properties. Herein, the fish oil-encapsulated powders were controlled prepared by combining a fish gelatin (FG)-alginate complex coacervation method with an intra-particulate genipin-crosslinking method. The genipin crosslinking did not affect the particle morphologies, moisture contents, and fish oil encapsulation ability. However, it did affect other physicochemical properties, fish oil oxidation ability, and in vitro digestion behaviors. Especially, the genipin-to-FG mass ratio of 1.0% induced the lowest water activity (0.45 ± 0.01), highest tapped density (0.107 ± 0.007 g/cm³), highest Carr indexes (58% ± 2%), highest Hausner ratios (2.43 ± 0.13), lowest peak value (636.0 ± 10.0 μm) of the powder sizes, and lowest peroxide peak value (442 ± 3 mmol/kg oil). This work provided useful information to understand the relationship between genipin modification and the properties of the fish oil-encapsulated powders.