Influence of physical state of β-carotene (crystallized versus solubilized) on bioaccessibility.

β-Carotene has potentially beneficial biological effects. However, its use is currently limited because of its low water-solubility, high melting point, and low oral bioavailability. This study investigated the influence of physical state (crystalline versus solubilized) on the bioaccessibility of β-carotene using a simulated gastrointestinal tract (GIT) model. Three delivery systems were compared: (1) β-carotene predissolved in a nanoemulsion; (2) β-carotene crystals mixed with a nanoemulsion; and (3) β-carotene crystals mixed with a phosphate-buffered saline (PBS). The changes in the microstructure of the delivery systems were characterized after each stage of the GIT model. The β-carotene bioaccessibility decreased in the order of delivery system 1 ≫ 2 > 3, which indicated that carotenoids solubilized within a oil phase were much more bioaccessible than those that formed crystals. This study provides important information for developing effective delivery systems for lipophilic bioactive components in food and beverage applications.