Characterization and in vitro bioavailability of β-carotene: Effects of microencapsulation method and food matrix

The objectives of this study were to determine the effect of microencapsulation method on physical properties and in vitro release and bioavailability of three types of β-carotene: a spray-dried powder of β-carotene and maltodextrin, commercially available water-dispersible β-carotene powder, and chitosan-coated β-carotene alginate. In vitro digestion trials were conducted with and without food matrices (yogurt, pudding) to elucidate the effect of food matrix on in vitro release and bioavailability. Microencapsulation method significantly affected (p < 0.05) water activity, moisture content, and particle size. The maltodextrin powder had the lowest moisture content (3.5%) and the smallest volume mean diameter (10.5 μm), whereas the chitosan-alginate beads had the lowest water activity (0.195). The maltodextrin powder had the highest surface β-carotene content (39.5%), while the commercial water-dispersible powder had the highest β-carotene content (10%). The microencapsulation method significantly influenced (p < 0.05) release and incorporation into micelles, regardless of food matrix. Water-dispersible β-carotene achieved the highest release (93.3%) and the highest incorporation into micelles (36.4%) in the absence of a food matrix, and the highest release (34.8%) and the highest micelle content (17.0%) with pudding. Food matrix significantly decreased release and micelle incorporation (p < 0.05), with yogurt decreasing release and micelle incorporation more than pudding.