Fabrication and characterization of curcumin-loaded albumin/gum arabic coacervate

In this study, gum arabic (GA) and bovine serum albumin (BSA) were used for encapsulation of poorly water-soluble curcumin (CN) by complex coacervation method. To optimize coacervate formulation, three factors including pH (3.7-4.2), BSA/GA weight ratio (3: 1, 2: 1, 1: 1) and CN content (1000-5000 mg), at three levels were examined in central composite design (CCD) using response surface methodology (RSM). A quadratic polynomial equation was used for encapsulation efficiency (EE) optimization. The complex coacervation between GA and BSA was restricted to a narrow pH range, where both molecules carry maximum opposite charges. Optimum conditions were found at BSA/GA weight ratio of 2: 1 and pH 3.7. Encapsulation efficiency in this condition was found to be around 92%. Scanning electron microscopy (SEM) revealed a sponge-like coacervate phase and showed the size in the range of 40-80 mm. Further characterization of dried coacervates was performed using XRD and DSC. Penetration test showed that among three mentioned variables, biopolymers ratio had a dominant effect on texture. This study showed that the BSA/GA emulsification-coacervation is an efficient and promising technique for CN encapsulation according to encapsulation efficiency and facility of the method. (C) 2015 Elsevier Ltd. All rights reserved.