Cellular Uptake of Carotenoid-Loaded Oil-in-Water Emulsions in Colon Carcinoma Cells in Vitro

Oil-in-water emulsions allow the preparation of lipophilic compounds such as carotenoids in the liquid form. Here, the effect of a combination of some emulsifiers, such as two whey protein isolates (BiPro and BioZate), sucrose laurate (L-1695), and polyoxyethylene-20-sorbitan-monolaurate (Tween 20), on the stability of lycopene and astaxanthin in emulsions, droplet size, and cellular uptake of these carotenoids has been investigated. The degradation of lycopene was slightly more pronounced than that of astaxanthin in all emulsions. The concentration of lycopene and astaxanthin decreased by about 30% and 20%, respectively, in all emulsions after 3 weeks of storage in the dark at 4 °C. The kind of emulsifiers or their combinations have played an important role in the cellular uptake by the colon carcinoma cells line HT-29 and Caco-2. Keywords: Astaxanthin; lycopene; O/W emulsion; cellular uptake; chemical and physical stability