Impact of saccharides and amino acids on the interaction of apple polyphenols with ion exchange and adsorbent resins

Model solutions containing catechin, caffeic acid, chlorogenic acid, phloridzin and rutin were used to examine their recovery using two adsorbent resins, four cation and four anion exchange resins at two temperatures (20 °C and 40 °C) and two pH values (pH 1 and 7). In addition, the interference of glucose, fructose and sucrose and of a saccharide mixture on polyphenol binding by one anion exchange and two adsorbent resins was assessed to approximate real conditions. In a further step polyphenol recovery using the aforementioned adsorbent and ion exchange resins was studied upon the addition of the amino acids alanine, glutamic acid, phenylalanine, lysine and histidine. The data reveal that both saccharides and amino acids influence polyphenol recovery positively and negatively, depending on the experimental conditions and the resin type; possible explanations for these findings are discussed. The information obtained in this study helps to gain a better understanding of the complex mechanisms of ion exchange and adsorption processes involving multi-component systems. The insights gained allow to design cost-efficient recovery of plant secondary metabolites from crude extracts for producing tailor-made health-beneficial fractions.