Impact of the Addition of Disaccharides on the Encapsulation of Chokeberry Polyphenols on Rice and Pea Proteins

Promising approach for the expansion of the functional food sector is combining various ingredients with potential health benefits. The aim of this study was to create protein aggregates by freeze-drying encapsulation. Rice or pea proteins were used as carriers for encapsulation of chokeberry juice polyphenols. Additionally, disaccharides (sucrose and trehalose) were added to explore possible enhancement of encapsulation of polyphenols. Two methods were employed for complexation of ingredients prior to freeze-drying: one based on complexation of all ingredients at the same time and the other on complexation first of proteins with disaccharides and then with chokeberry juice. All parameters affected the binding of polyphenols on proteins. Total polyphenols, proanthocyanidins, individual polyphenols, and antioxidant potentials of created protein aggregates were determined. When rice protein was the main carrier, the addition of disaccharides caused a decrease in total polyphenols and proanthocyanindins contents (22.41-24.01 mg GAE/g and 6.36-7.28 mg PB2E/g, respectively) in comparison to aggregates without their addition (28.03 mg GAE/g and 8.57 mg PB2E/g, respectively). In the case of pea proteins, a different trend was observed. Aggregates without disaccharide addition had a lower amount of total polyphenols and proanthocyanindins (21.25 mg GAE/g and 5.56 mg PB2E/g, respectively) than those with disaccharide addition (21.42-26.44 mg GAE/g and 6.37-9.45 mg PB2E/g, respectively). Interactions between compounds were proven through IR spectra, and they included changes in amid structures, as well as hydrogen bonds and hydrophobic interactions. Such formulated plant-based protein aggregates can be used in the food industry for the enrichment of foods with polyphenols, incensement of antioxidant potential, and prolonging stability of products.