Fabrication, characterization and in vitro digestion of food-grade β-carotene high loaded microcapsules: A wet-milling and spray drying coupling approach

Abstract β-Carotene high loaded microcapsules were fabricated via coupling the wet-milling and spray drying without employing any organic solvent or solubilizing oil. The impact of process parameters, including milling time and spray-drying inlet temperature, on the physicochemical stability, redispersibility, micromorphology and in vitro digestion of β-carotene microcapsules was investigated. The optimized microcapsules exhibited a small average diameter after rehydration (229.4 nm) with ultrahigh encapsulation efficiency and loading capacity (99.18 % and 19.17 %, respectively). The crystalline β-carotene was not completely transformed into amorphous state with a final crystallinity of 13.79 %. The morphology of microcapsules was dependent on the milling time and spray-drying inlet temperature, and the best integrity and uniformity of microcapsules were achieved after milling for 150 min and spray-dried at 105 °C. Furthermore, the in vitro release rate of β-carotene during the simulated gastrointestinal digestion was increased from 12.08 % to 33.72 % by extending the milling time and decreasing the inlet temperature of spray drying.