Assessment of carotenoid bioavailability of whole foods using a Caco-2 cell culture model coupled with an in vitro digestion.

Epidemiological studies have shown that consumption of carotenoid-rich fruits and vegetables is associated with a reduced risk of developing chronic diseases. beta-Carotene, alpha-carotene, and beta-cryptoxanthin are precursors of vitamin A, a nutrient essential for human health. However, little is known about the bioavailability of carotenoids from whole foods. This study characterized the intestinal uptake performance of carotenoids using monolayers of differentiated Caco-2 human intestinal cells and mimicked human digestion to assess carotenoid absorption from carrots and corn. Results showed that Caco-2 cellular uptake of beta-carotene and zeaxanthin was higher than that of lutein. Uptake performances of pure carotenoids and carotenoids from whole foods by Caco-2 cells were both curvilinear, reaching saturated levels after 4 h of incubation. The time kinetics and dose response of carotenoid uptake presented a similar pattern in Caco-2 cells after plating for 2 and 14 days. Furthermore, the applicability of this new model was verified with whole grain corn, showing that cooked corn grain significantly enhanced carotenoid bioavailability. These results support the feasibility of the in vitro digestion cell model for assessing carotenoid absorption from whole foods as a suitable and cost-effective physiological alternative to current methodologies.