Aqueous solutions containing different amounts of alginate
were prepared by dissolving powdered alginic acid (1% or 2%, w/w)
in distilled water and stirring continuously at 60 C for an hour, and
then reducing the temperature to 35 C. Alginate solutions and bcarotene-
loaded emulsions were then mixed together (1:1, mass
ratio) for 2 h with continuous stirring to form a mixture that contained
5% oil (w/w) and either 0.5% or 1% alginate (w/w). The bcarotene-
loaded hydrogel beads were prepared using a commercial
encapsulation unit (Encapsulator B-390, BUCHI, Switzerland) with
a 120 mmvibrating nozzle to inject the b-carotene/alginate solution
into 10% calcium chloride solution. The encapsulation device was
operated under fixed conditions: frequency 800 Hz; electrode
800 V; and pressure 450 mbar. The hydrogel beads were held in the
Ca2þ solution for 1 h at ambient temperature to promote crosslinking.
The beads were then collected by filtration and subsequently
washed with distilled water and phosphate buffer to
remove any excess ions from their surfaces. The formed beads were
then storage in a refrigerator so that any residual external water
was removed, and then their total weight was determined.
biomacromolecules