Preparation of phycocyanin microcapsules and its properties

• Phycocyanin/alginate/chitosan microcapsules were prepared by an extrusion method.
• Microencapsulation conferred greater stability to phycocyanin during storage.
• Microcapsules could rapidly release phycocyanin under mild alkali condition.

Phycocyanin was microencapsulated by an extrusion method using alginate and chitosan as coating materials. This work was aimed to optimize the encapsulation process, characterize the physicochemical properties of microcapsules, and evaluate the storage stability and in vitro release performance. The optimum process conditions for preparing microcapsule gained from the single factor experiments were as follows: alginate content 2.5%, ratio of phycocyanin to alginate 1.5:1, content of calcium chloride 2.5%, and chitosan content 2.0%. Phycocyanin/alginate/chitosan microcapsules (PACM) were found to have compact spherical shape with mean diameters of 1.03 mm, whereas phycocyanin/alginate microspheres (PAM) were internal porous spherical appearances with mean diameters of 1.81 mm. Storage stability study showed that encapsulation by alginate and chitosan conferred greater ability to phycocyanin against temperature during storage. In vitro release study revealed that both PAM and PACM could be resistant against acidic environment, and would rapidly release phycocyanin under mild alkali condition. The sustained-release profile of phycocyanin from PACM was superior to that from PAM.