Cellulose nanofiber-based bigels for co-encapsulation of l-ascorbic acid and β-carotene: structural characteristics and release behavior.

This study developed a bigel system capable of simultaneously encapsulating l-ascorbic acid and β-carotene using cellulose nanofiber hydrogel and glycerol monostearate oleogel. The effects of varying the oleogel-to-hydrogel ratio on the structural characteristics and bioactive compound loading capacity of the bigel system were investigated. Specifically, systems with a balanced oil-water ratio exhibited a uniform interpenetrating network structure and stability. Additionally, the bigel demonstrated high loading efficiency and effectively delayed the release of these active compounds at different temperatures. In vitro simulated digestion kinetics indicated that the release of both l-ascorbic acid and β-carotene was best described by the Korsmeyer-Peppas model. The release exponent (n < 0.45) suggested a Fickian diffusion-controlled release mechanism, in which the transport of bioactive compounds was primarily governed by concentration-gradient-driven diffusion through the bigel matrix. In conclusion, the bigel facilitates the co-encapsulation and controlled release of both hydrophilic and hydrophobic active compounds, offering novel insights and promising applications for the design of functional foods.