Digestibility of polymerized whey protein using in vitro digestion model and antioxidative property of its hydrolysate

Polymerized whey protein (PWP) is whey protein aggregates formed by heating whey protein at certain conditions. PWP has been successfully used as thickening agent, fat replacer and microcapsule wall material. However, the digestion properties of PWP have not been systematically investigated. This study aims to analyze zeta potential, particle size, peptide composition, and antioxidative property of digested PWP (prepared by heating at 70–85 °C for 10–30 min) obtained by hydrolyzing with pepsin and trypsin sequentially using in vitro digestion model. Digestive products of PWP heated at 85 °C showed more significantly negative zeta potential in comparison with that of control sample (p