Physical Properties of Fish Oil Microcapsules Prepared with Octenyl Succinic Anhydride-Linked Starch and Maltodextrin

The microcapsules of fish oil were prepared through spray drying with octenyl succinic anhydride-linked starch (OSA-S) and maltodextrin (MD) as wall materials. The physical properties of microcapsules were evaluated, such as microstructure, hygroscopicity, dissolution, the average particle size, and rheological properties. It was found that the microcapsules were spherical with some wrinkle on the surface as observed by an optical microscope and a scanning electron microscope. Furthermore, the holes in the shell of microcapsules were fish oil droplets as shown in a laser confocal microscope, indicating that the fish oil microcapsules were a typically multinucleated system. In addition, there was no significant change in average particle size (0.2-0.9 mu m) after 1-month storage at room temperature, and there was no chemical reaction between the wall materials and fish oil as was proven by infrared spectra. Finally, reconstituted emulsions (RCE) of microcapsule exhibited shear-thinning behavior at low shear rate, which was helpful to the processing, transportation, and storage of emulsion.