A novel complex coacervate formed by gliadin and sodium alginate: Relationship to encapsulation and controlled release properties

This paper investigated the formation of a novel complex coacervate between gliadin (G) and sodium alginate (SA) as well as its relationship with the encapsulation and controlled release properties by loading curcumin (Cur). G-SA coacervates (GSAC) were fabricated using the anti-solvent method to form gliadin nanoparticles (GNPs) and then electrostatic deposition with SA to form coacervates. Based on the turbidimetric analysis and zeta-potential results, coacervates were formed at a wide range of pH (1.0-7.0) through electrostatic interaction in the gliadin-SA system. The gliadin-SA interaction was spontaneous exothermic process shown by the isothermal titration calorimetry. The spherical particles of curcumin-loading G-SA coacervates (GSAC-Cur) with well-homogeneity and great-dispersion as well as particle aggregation were observed on SEM. At coacervated pHs, GSAC-Cur showed particle size from 433.55 to 1496.50 nm, PDI around 0.28, zeta-potential from -1.9 to -50.9 mV and encapsulation efficiency from 61.29% to 81.01%. Controlled release profiles confirmed that G-SA coacervates reduced the released speed of curcumin in the release process. In summary, we concluded that the properties of GSAC-Cur corresponding to the embedding and controlled release could be better by forming coacervates via pH-induced.

Automated summary

In this study, a novel complex coacervate between gliadin and sodium alginate was formed and successfully loaded with curcumin, demonstrating spherical particles with good homogeneity and dispersion. The formation of coacervates at different pH induced by electrostatic interaction reduced the release speed of curcumin, leading to better encapsulation and controlled release properties.