Abstract: The aim of this study was to investigate the effect of high pressure homogenization (0–4 cycles) on the rheological properties and oxidative stability of soy protein isolate (SPI)-stabilized emulsion system. The results showed that with the increase of homogenization cycles, creaming index, average particle size, the amount of interfacial protein adsorption, apparent viscosity, elastic modulus (G’) and viscous modulus (G”) increased firstly and then decreased. Hydroperoxide value (primary oxidation product) of the emulsion system continued to increase, and thiobarbituric acid reactive substances (TBARS; secondary oxidation products) value increased firstly, then decreased and finally increased once again. After three cycles of homogenization, no precipitation occurred, and the amount of interfacial protein adsorption, apparent viscosity, and G’ and G” reached their maximum; in contrast, the lowest hydroperoxide value and TBARS value were observed. As explained above, high pressure homogenization can improve the stability, rheological properties and oxidative stability of the SPI-stabilized emulsion system.

Key words: soy protein isolate, high pressure homogenization, rheological properties, oxidation stability