Fucoxanthin-Loaded Oil-in-Water Emulsion-Based Delivery Systems: Effects of Natural Emulsifiers on the Formulation, Stability, and Bioaccessibility

The effect of natural emulsifiers (whey protein isolate, WPI; modified lecithin, ML; and gum arabic, GA) on the formulation, stability, and bioaccessibility of fucoxanthin-loaded oil-in-water (O/W) emulsions was determined in this study. The fine emulsions were prepared under high-pressure homogenization at 100 MPa for 4 passes, using 2 wt % WPI, ML, and GA, resulting in emulsions with the droplet sizes of 136, 140, and 897 nm, respectively. The chemical stability of fucoxanthin in the emulsions after long-term storage at ambient temperature decreased in the following order: WPI > GA > ML. The release of free fatty acids of fucoxanthin, studied by in vitro digestion, decreased in the following order: WPI > ML > GA > bulk oil. The bioaccessibility of fucoxanthin in emulsions stabilized by WPI, ML, and GA after in vitro digestion were 92.5 +/- 6.8%, 44.6 +/- 0.4, and 36.8 +/- 2.5, respectively. These results indicate that natural emulsifier type and concentration used significantly affects the formulation, stability, lipid digestion, and fucoxanthin bioaccessibility, which may be ascribed to the different properties of each emulsifier. The bioaccessibility of fucoxanthin was improved by using emulsion-based delivery systems.