Bioaccessibility of β-carotene during in vitro co-digestion of encapsulated mango peel carotenoids with milk

R-carotene is a carotenoid with provitamin A activity whose digestive stability and bioaccessibility prior to intestinal absorption are important to fully exploit its health benefits. Microencapsulation protects carotenoids, but there is a lack of information on the extent to which its characteristics and interactions with complex food matrices could impact the carotenoid micellization during digestion. We evaluated the effect of milk fat content on the in vitro bioaccessibility of R-carotene from microparticles containing carotenoids from mango peel. The microparticles tested contained solvent-extracted carotenoids and supercritical fluid-extracted carotenoids, and were separately co-digested with whole, semi-skimmed and skimmed milks. Bioaccessibility was assessed using an in vitro digestion method adapted to carotenoids. R-carotene recoveries after in vitro digestions ranged from 79.6 to 102.2 %, with the highest values corresponding mainly to microparticles with the lowest initial R-carotene concentration. R-carotene bioaccessibilities ranged from 8.8 to 75.5 %, the highest values being obtained mainly when the microparticles were co-digested with whole milk, especially when those containing supercritical fluid-extracted carotenoids were used. The bioaccessibility-enhancing effect of the milk fat was explained by the higher concentration of free fatty acids in the micellar phase, while the better results in the microparticles containing supercritical-fluid-extract was attributed to the lower initial concentration of R-carotene. In conclusion, increasing the milk fat content increased the bioaccessibility of encapsulated R-carotene from mango peel, further determining that, a lower initial concentration of R-carotene in the microparticles resulted in higher bioaccessibility.