β-lactoglobulin as a vector for β-carotene food fortification.

Food fortification is a strategy to overcome vitamin A deficiency in developing countries. Our aim was to investigate the involvement of the bovine milk protein β-lactoglobulin (β-Lg), a potential retinoid carrier, in vitamin A absorption. In vivo experiments were conducted by force-feeding mice with retinol or β-carotene associated with either β-Lg or oil-in-water emulsion, with subsequent determination of both vitamin A intestinal mucosa and plasma contents. Caco-2 cells were then used to investigate the mechanisms of vitamin A uptake when delivered by either β-Lg or mixed micelles. We showed that β-Lg was as efficient as emulsion to promote β-carotene, but not retinol, absorption in mice. Similar results were obtained in vitro. Interestingly, an inhibitor of the Scavenger Receptor Class B Type I significantly decreased the uptake of micellar β-carotene but not that of β-carotene bound to β-Lg. Overall, we showed that β-Lg would be a good vector for β-carotene food fortification.