Alginate-chitosan microspheres for controlled release of tea polyphenol

Tea polyphenol loaded alginate-chitosan microspheres were prepared by ionic gelation method for controlling tea polyphenol release by using various combinations of chitosn and Ca2+ as cation and alginate as anion. Scanning electron microscopy were used to investigate the surface characteristics of tea polyphenol loaded microspheres. These microencapsulated beads were evaluated as a pH-sensitive system for delivery of tea polyphenol. The main advantage of this system is that all procedures used were performed in aqueous medium which may preserve the tea polyphenol bioactivity. At pH7.4, the amounts of tea polyphenol released increased significantly as compared to those released at pH 1.2. It is evident that the rate of tea polyphenol release could be controlled by changing the chitosan and the calcium chloride concentrations.