Shape control and stability of multicore millimetre-sized capsules using a combined monoaxial dispersion electrospraying–ionotropic gelation technique

Multicore millimetre-sized fish oil-loaded alginate capsules were developed using a combined monoaxial dispersion electrospraying–ionotropic gelation technique and their stability was explored. By adjusting the preparation parameters, the capsule shapes could be irregular, spherical with a short-tail, spherical, fusiform, and fusiform with a long-tail. The continuous phase of the millimetre-sized capsules consisted of hydrophilic alginate calcium and water. Moreover, the water content increased from 17% to 69% with increased alginate concentration (2.5–30 mg mL⁻¹). The capsules prepared with alginate concentration of 10 mg mL⁻¹ or 20 mg mL⁻¹ show a similar loading ratio (about 5–8%) of fish oil during storage. Headspace solid-phase microextraction–gas chromatography mass spectroscopy (HS-SPME-GC-MS) results confirmed the capsules masked the fishy odour of fish oil. Moreover, fish oil slowly migrated from the inside to the outside of the capsules. This work presented a simple method to prepare multicore millimetre-sized capsules with controlled shapes and a basic understanding of the effect of encapsulation using alginate to mask the fish oil odour.