Dependence of Thermal Properties as Well as Network Microstructure and Rheology on Protein Concentration for Ovalbumin and Vicilin

Critical protein concentration (CPC) values for network formation for ovalbumin (5.5%, w/w) and vicilin (8%, w/w) were determined based on the appearance of a well crosslinked network using light microscopy, in conjunction with a significant decrease in the dynamic rheological parameter, tan δ= G″/G′. Increasing protein concentration resulted in increased G′ (storage modulus) and G″ (loss modulus) for both proteins. These relationships were described by power law equations. Ovalbumin networks had a lower CPC and tan δ value at protein concentrations above the CPC than did vicilin networks. This was related to a greater increase in the G′ and G″ moduli during the initial stages of cooling.