Exploring anthocyanins-polysaccharide synergies in microcapsule wall materials via spray drying: Interaction characterization and evaluation of particle stability

Abstract

Anthocyanins are unstable under processing and storage conditions. In this sense, microencapsulation using polysaccharides as wall materials has been used as a viable alternative to improve stability. On the other hand, there are no studies that evaluate the interactions between polysaccharides and anthocyanins to explain how this stabilization occurs. The present work carried out infrared (FTIR), zeta potential and thermogravimetry analyzes to evaluate the possible interactions between maltodextrin, Capsul® and gum arabic with purified anthocyanins. In this study, it was observed that microcapsules produced with maltodextrin had a higher content of anthocyanins on their surface, and FTIR analysis identified intermolecular hydrogen bonds between all wall materials and anthocyanins. Through zeta potential analysis, an electrostatic bond in the surface layer between anthocyanins with maltodextrin or Capsul® is suggested. The interaction between maltodextrin and anthocyanins thermally stabilized the microcapsules. Among the materials studied, maltodextrin showed the highest interaction affinity with anthocyanins. Capsul® did not present a microcapsule with good thermal stability, which shows that the anthocyanins must be protected in the nucleus for this. Furthermore, gum arabic and maltodextrin showed evidence of intermolecular hydrogen bonds with anthocyanins. In the case of gum arabic, it was concluded that anthocyanins were more localized in the core of the microcapsules.