Chokeberry Pomace as a Source of Polyphenols for Complexation with Plant-Based Proteins

One way to utilize by-products from fruit production is the extraction of bioactive compounds and their subsequent complexation with appropriate carriers. Consequently, we used chokeberry pomace extract for complexation with plant-based proteins, namely almond, rice, pea, and pumpkin-seed protein matrices, which differ in their composition and protein content. The obtained complexes, as well as the chokeberry pomace extract and protein matrices, were evaluated for the concentration of individual polyphenols, total polyphenols, procyanidins, and antioxidant activity. Color parameters and IR spectra were also recorded. The results of this study emphasized the importance of the structure and properties of polyphenols and proteins, which are significant factors affecting polyphenol adsorption onto protein-based carriers. All proteins showed similar affinity for anthocyanins (69% for cyanidin-3-galactoside, and 23% to 29% for cyanidin-3-arabinoside). Rice proteins had the highest affinity for quercetin-3-rutinoside (87%), while pumpkin proteins showed the highest affinity for quercetin-3-galactoside (87%) and quercetin-3-glucoside (65%). Rice proteins also had the highest affinity for phenolic acids (67% for neochlorogenic acid, 81% for chlorogenic acid, and 48% for isochlorogenic acid). These results provide a good baseline for the formulation of dried protein-based complexes, based on chokeberry pomace, rich in polyphenols which can have possible uses in food products, to enhance their antioxidant potential.