Highly efficient encapsulation of anthocyanins by complex coacervates prepared from pectin and chickpea proteins

Interactions between proteins and polysaccharides can form novel complex structures with unique functionalities, making protein-polysaccharide coacervates highly promising for applications in the food and pharmaceutical industries. The aim of this study was to prepare coacervates using apple pectin as the polyanion and chickpea proteins as the polycation, and to evaluate their efficiency in encapsulating anthocyanins from aronia juice, along with their potential for controlled and targeted delivery. Proteins were extracted from chickpea by different protocols - by conventional alkaline extraction or by alkaline extraction assisted with ?-L-arabinofurosidase. The zeta potential was measured at range of pH values from 1 to 6, and mixing ratio pectin:protein was varied from 1:1 to 1:3. Additionally, the amount of anthocyanins bound by individual protein-pectin complex was determined. Results showed that applied conditions - mixing ratio 1:1, pH 2.6 and 2.8 for alkaline and enzyme-assisted alkaline protein isolate, respectively, led to the formation of stable coacervates with the ability to bind anthocyanins from aronia juice. The coacervates prepared with proteins extracted by alkaline extraction and arabinofuranosidase-assisted alkaline extraction bound 55% and 49% of anthocyanins, respectively. The results demonstrated considerable potential of the investigated pectin- protein coacervates for effective encapsulation of anthocyanins and their controled and site-specific delivery.