Wall material, consisting of SCF 70 with WPI or SC as emulsifiers
(in a mass ratio of 1:1), was dissolved in 700 g distilled water.
The solution was allowed to hydrate for at least 1 h before emulsion
preparation and held in a 50 C water bath to ensure a full dissolution
of the emulsifiers, followed by cooling down to room
temperature. Core material, including sunflower oil and Cynatech
Bioastin astaxanthin, was added to the solution in a mass ratio to
the wall material of 1:4. The total concentration of the dissolved
solids (wall and core materials) was 30% of the weight of final
emulsion. The pH of pre-emulsions was adjusted to around 6.7
using 1 M NaOH or 1 M HCl as required. Coarse emulsions were
prepared using an Ultraturrax Janke & Kunkel T25 homogeniser
(Germany) at 13,500 rpm for 2 min, and then passed through a
two-stage homogeniser (APV, Denmark) at 80 and 800 bars.