Quinoa bioactive protein hydrolysate produced by pancreatin enzyme-functional and antioxidant properties

Quinoa protein with great functional properties has been considered a potential source for food fortification or the production of functional foods. In this study, quinoa protein hydrolysate (QPH) was prepared from quinoa protein concentrate (QPC) after hydrolysis by pancreatin (pancreatic) enzyme. The emulsifying, foaming, and antioxidant activities, the emulsion and foam stabilization, as well as amino acid profile and chemical composition were evaluated. The highest degree of hydrolysis (19.17%) was obtained after 180 min. The amino acid profile (by high-performance liquid chromatography: HPLC) showed that glutamic acid and lysine had the highest contents and all essential (limiting) amino acids were recorded. Fourier-transform infrared (FTIR) spectroscopy showed hydroxylic and aromatic amino acid residues in the QPC and it was inferred that different functional groups have originated in QPH that confirms the hydrolyzing action of pancreatin enzyme. QPH had the lowest solubility at the isoelectric pH of 5 (pI similar to 5) and had better emulsifying, foaming, and antioxidant properties compared to QPC. In contrast, QPC had better emulsion/foam stabilizing properties. Overall, this study suggests that pancreatin could be employed for hydrolysis of quinoa protein and its hydrolysate with functional properties could be possibly considered for food fortification or production of functional foods.