Relations between rheological properties and network structure of soy protein gels

Abstract

This paper focuses on the relations between network structure and rheological properties of soy protein gels as a function of pH and ionic strength. Network structure has been characterized independently by permeability measurements and confocal scanning laser microscopy in terms of coarseness. Results showed that gels at pH 3.8 and 5.2 were coarser than at pH 7.6, except for pH 3.8–0 M NaCl. Rheological properties determined were dynamic moduli, Young's modulus, fracture stress and fracture strain. Gels at pH 3.8 had lower fracture strains and higher moduli than gels at pH 5.2 and 7.6, while fracture stresses were about the same. To relate the rheological properties to network structure in a self-consistent way, an additional structural parameter was required: curvature of the strands.