Carotenoid–protein interaction as an approach for the formulation of functional food emulsions

Functional foods represent an emerging market of growing economic importance. The formulation of carotene fortified food emulsions involves the difficulty to transfer the carotenoids into the lipid phase. Usually, undesirable organic solvents are used to dissolve the carotenoid in the lipid phase, in particular astaxanthin and β-carotene. Here, we present a novel approach in which the carotenoid is first bound to bovine serum albumin (BSA) and then the carotenoid–protein complex is used to prepare an emulsion. Absorbance spectroscopy indicates the formation of the complex in the aqueous phase and provides first results of the carotenoid load, which is supported by the colour of the cream phase. The droplets in the emulsion are visualized by confocal laser scanning spectroscopy, indicating the protein layer. The laser diffraction spectroscopy and confocal laser scanning spectroscopy provide the particle size distribution and insight of the stability of emulsion interface.