Physicochemical and functional properties of anthocyanin microparticle encapsulated by ovalbumin and chitosan

Anthocyanins (ACN) is a group of phytochemicals with various health promoting functions. However, the low stability limits their application. In this study, anthocyanin microparticles were prepared by encapsulating cyanidin-3-O-glucoside using ovalbumin-carboxymethyl chitosan (OC) complex. The final microparticles appeared in oval capsule form and had encapsulation rate from 44 to 52 %. The complex with 5 h of reaction time showed the highest free water content and fluidity, which were favorable for ACN encapsulation. The prepared microparticles had the best foaming capability (41.4 %), foaming stability (58.69 %) and viscoelasticity (G′ 17.8Pa at 10Hz). The linkage of the complex and encapsulated anthocyanin was mainly through hydrogen bond. The encapsulated cyanidin-3-O-glucosides presented higher thermal stability than the free form and reached 45 % of retention rate after 5 h of heating at 90°C. They were also more resistant to pH change and had over 60 % of retention rate at pH 5. Therefore, these properties provided a wide-ranging application of the prepared microparticle in different functional foods with enhanced stability of ACN and improved bio accessibility and bioavailability. The approach of this study could have the potential for applying to other unstable bioactives in functional food application.