Beta-carotene: Digestion, Microencapsulation, and In Vitro Bioavailability

Beta-carotene is an important nutrient for human health, but its low absorption from natural sources has led to the development of microencapsulation methods to improve stability and bioavailability. To properly design a gastrointestinal delivery system for beta-carotene, the processes occurring during digestion from mastication to absorption must first be understood. This review provides an overview of beta-carotene digestion and microencapsulation methods, with an emphasis placed on spray-drying and gelation. Given the lack of a standardized in vitro model to study the bioavailability of beta-carotene, important parameters that have been shown to affect bioavailability of beta-carotene (i.e., pH, enzyme concentration, type of model) are discussed to ensure measurements are made using physiologically relevant conditions. Current quantitative methods to measure beta-carotene after digestion are evaluated to ensure accuracy and precision of measurements. This study contributes to the knowledge concerning beta-carotene digestion, release, and absorption and provides guidelines for developing microencapsulation methods and in vitro digestion protocols to accurately measure in vitro bioavailability.