Effect of heat treatment on the properties of soy protein‐stabilised emulsions

The effect of heat treatment on the properties of soy protein‐stabilised emulsions was investigated. Emulsions were prepared with unheated and heat‐treated soy protein (NSP and HSP) dispersions. Heating on soy protein dispersions at 95 °C for 30 min resulted in smaller average oil droplet size, lower tendency for oil droplet flocculation, higher protein adsorption and lower viscosity. The properties of emulsions were significantly influenced by the protein concentration. The sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) profiles showed that the heat treatment on soy protein dispersions increased the protein adsorption at O/W interface. The viscosity of all samples at low shear rate was inversely proportional to the d₃₂, suggesting a positive relation to the total interfacial area per unit volume. Emulsions showed shear‐thinning behaviour. The relaxation time was found to increase with aqueous phase viscosity determined by the Cross viscosity model.