Preparation and Properties of Chitosan Salicylaldehyde Hydrogel Loaded with Anthocyanins

In the presence of blueberry anthocyanins (ACNs), chitosan hydrogel crosslinking with salicylaldehyde (ACNs/CS-SA) was constructed. The structure and morphology of ACNs/CS-SA were characterized. The stability, swelling properties and ACNs controlled-release behaviors for the ACNs/CS-SA were investigated in the media of different pH. ACNs were uniformly dispersed in three-dimensional network structure of CS-SA hydrogel by physical embedding, which was confirmed by FT-IR and XRD characterization. The thermal stability of ACNs was significantly improved due to gelation, which was confirmed by TG-DTG characterization. Both the swelling properties and ACNs controlled-release behaviors for the ACNs/CS-SA exhibited pH response. In buffer media of pH2.7, 4.6 and 6.7, the cumulative release rates of ACNs for 24 h were 74.28%±4.58%, 40.72%±4.04% and 15.70%±1.71%, and the release process followed Weibull equation with the correlation coefficients R² 0.99405, 0.95165 and 0.99712, respectively. This study lays a theoretical and experimental foundation for the development of novel drug encapsulation materials and the application of ACNs owing to the ACNs/CS-SA pH responsiveness and ACNs thermal stability improvement.