Effects of high pressure on the physicochemical and functional properties of peanut protein isolates

This study aimed to investigate the effects of high pressure (HP) on the physicochemical and functional properties of peanut protein isolates (PPI). The properties studied were surface hydrophobicity (H0), contents of sulfhydryl group (SH) and disulfide bond (S–S), sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) characteristics, differential scanning calorimetric(DSC) characteristics, protein water-holding capacity (WHC), oil-binding capacity (OBC), and heat-induced gelling property. HP treatment from 50 MPa to 200 MPa for 5 min gradually increased the WHC and OBC, and significantly increased the H0 (p < 0.05). The hardness of the heat-induced gelling increased by 50% after HP treatment at 100 MPa, but gradually decreased with further increased pressure. HP treatment at 50–200 MPa significantly increased the S–S content (p < 0.05) but decreased the SH content. The content of conarrachin II significantly changed with HP treatment in SDS-PAGE. These results suggest that HP treatment can be used to modify the properties of PPI at the appropriate pressure within a short time.