Fabrication and characterization of Ca(II)-alginate-based beads combined with different polysaccharides as vehicles for delivery, release and storage of tea polyphenols

Abstract

In order to enhance the encapsulation efficiency of tea polyphenols (TP) and retard their diffusion from alginate hydrogel beads, we structured alginate network by coating or adding fillers. In the present study, alginate-based blends consisting of inulin, Arabic gum, or chitosan were prepared for assessment of the best formulation. Results indicated that encapsulation efficiencies of TP in plain alginate bead as well as beads reinforced with inulin, Arabic gum and chitosan were 38.51%, 36.48%, 48.56% and 57.76%, respectively, revealing that selected appropriate filler materials could indeed increase the encapsulation efficiency of TP. Additionally, the release profile of TP revealed that the porosity of alginate beads could not efficiently retard the diffusion of polyphenols from beads. However, alginate bead coated by chitosan gave the most retarded release of TP both in water and in the simulated gastrointestinal conditions. Moreover, TP encapsulated in the obtained beads could partly protect them from degradation during storage. Our results suggested that selected appropriate fillers or coating materials can indeed enhance the encapsulation efficiency of TP and retard their release, which could promote the application of TP as a functional ingredient in the food industry.