Structural and physicochemical properties of composites between starch nanoparticles and β-carotene prepared via nanoprecipitation

To apply starch nanoparticles (SNP) as host materials for β-carotene encapsulation, aqueous SNP dispersions (10, 25, 50, and 100 mg/10 mL) and β-carotene in acetone (10, 50, 100, 150, and 200 μg/mL) were mixed. The acetone in the mixture was evaporated to prepare SNP and β-carotene composites, which were homogeneously dispersed in aqueous media with over 90 % solubility. When SNP content was higher than 50 mg, over 80 % of β-carotene was encapsulated in the composite matrix. X-ray diffraction, nuclear magnetic resonance spectroscopy, and transmission electron microscopic analyses confirmed the micellar-shaped composite particles with diameters <120 nm and an amorphous structure. High SNP content in the composites enhanced β-carotene stability under extremely hot and acidic conditions as well as against ultraviolet rays and oxidation reactions. The encapsulated β-carotene was not readily released in simulated gastric fluid, but was gradually released in simulated intestinal fluid via SNP digestion in the composites.