Colloidosomes, a special type of multilayer emulsion, might
also offer advantages for protecting carotenoids solubilized in
a lipid carrier. Colloidosomes are produced by using electrostatic
attraction to coat an oil droplet with smaller droplets of
a second emulsion made with a surfactant of opposite charge
to the one used to make the larger primary emulsion (Gu et al.,
2007). As with multilayer emulsions formed with biopolymers,
colloidosomes have the advantages of forming a thick physical
barrier to inhibit contact with aqueous prooxidants, and may be
formulated in such a way as to allow for controlled release of
carotenoids. In addition, the smaller droplets used to coat the
carotenoid-containing, larger droplet could be loaded with concentrated
antioxidants to protect carotenoids in the inner droplet.
This might prove especially useful since the antioxidants would
be concentrated at the site of the prooxidant attack rather than
being diluted throughout the system.