Characterization and bioaccessibility of β-carotene in re-assembled casein
The characterization and bioaccessibility of β-carotene (β-CE) in re-assembled casein (CN) were investigated in this study. At pH 4.6, β-CE in re-assembled CN significantly lowered the zeta-potential to a negative value compared to that of CN. The morphology of β-CE in re-assembled CN was characterized by atomic force microscopy. β-CE in re-assembled CN exhibited a more uniform and homogenous dispersion, with peak-to-valley differences of 6.8 nm rather than 91.3 nm for the pure β-CE. β-CE in re-assembled CN can effectively protect β-CE against degradation under conditions of heat and ultraviolet radiation. The antioxidant activity of β-CE when it was encapsulated in re-assembled CN was significantly higher than β-CE in control samples under both experimental conditions. The total release rate of β-CE was 76.7% and 63.4% by trypsin and pepsin hydrolysis, respectively. These results indicated a feasible application in the food industry.