Effects of Different High Hydrostatic Pressure Treatments on Gel Formation of Pea 7S and 11S Globulins

Abstract

In this study, the rheological and textural properties and water-holding capacity of pea 7S and 11S globulin gels induced by high hydrostatic pressure (HHP) at 100–500 MPa for 10 min were measured. The major interaction forces maintaining gel morphology were determined by dissolving the gels in different solvents. The microscopic structure of the gels was observed using scanning electron microscopy (SEM). The results showed that after HHP treatment at 300 MPa, pea 7S and 11S globulin solutions gradually turned into gels. When the pressure continued to increase to 500 MPa, the formed gels exhibited higher strength, harder texture and higher water-holding capacity. The 11S globulin had weaker gel-forming ability, but higher water-holding capacity (100%) compared with 7S. Furthermore, the overall water-holding capacity and gel strength of 7S–11S mixed gels (in mass ratios of 1:2, 1:1 and 2:1) were significantly improved compared with those of the neat gels. The major forces that maintain the gel structure were hydrogen bonds and hydrophobic interaction, followed by disulfide bonds and electrostatic interaction. Therefore, by changing HHP conditions, the strength and texture of pea globulin gels could be controlled.

Keywords

• pea globulin; high hydrostatic pressure; gel; rheological properties; structure