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 ζ-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, ζ-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.