Properties and kinetics of the in vitro release of anthocyanin-rich microcapsules produced through spray and freeze-drying complex coacervated double emulsions

Abstract

This study aimed to prepare anthocyanin-rich microcapsules by spray and freeze-drying complex coacervated double emulsion using gelatin-acacia gum (GE-AG) and chitosan-carboxymethylcellulose (CS-CMC) and to investigate their properties and in vitro release kinetics. Microencapsulation efficiency (MEE) of the microcapsules varied from 84.9% to 94.7%. CS-CMS microcapsules showed significantly higher MEEs than those of GE-AG microcapsules. A significant higher MEE and lower moisture content and hygroscopicity was observed in spray-dried double emulsion (SDE) microcapsules. Freeze-dried double emulsion (FDE) microcapsules possessed higher total anthocyanin and total phenolic contents. The best fit for release kinetics was achieved using first-order and Higuchi models for SDE and FDE microcapsules, respectively. Diffusion-controlled release in the simulated gastric fluid was found for SDE microcapsules, while erosion-controlled release in simulated gastric and intestinal fluids predominated for FDE microcapsules. These findings suggest that the microcapsules can be applied for loading anthocyanins as a nutraceutical with controllable release requirement.

Keywords: 2,2-Diphenyl-1-picrylhydrazyl (DPPH) (PubChem CID: 2735032); 3,4,5-Trihydroxybenzoic acid (gallic acid) (PubChem CID: 370); 6-Hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox) (PubChem CID: 40634); Bile salts (PubChem CID: 439520); Black rice; Carboxymethylcellulose sodium (PubChem CID: 6328154); Chitosan (PubChem CID: 71853); Complex coacervation; Distilled water (PubChem CID: 962); Double emulsion; In vitro gastrointestinal digestion; Potassium chloride (PubChem CID: 4873); Release behavior; Sorbitan monooleate (span 80) (PubChem CID: 9920342); Urea (PubChem CID: 1176).