Foaming, emulsifying properties and surface hydrophobicity of soy proteins isolate as affected by peracetic acid oxidation

ABSTRACTIn this study, the effects of the disulfide bond cleavage induced by peracetic acid oxidation on the surface properties and surface hydrophobicity of soy proteins isolate (SPI) were investigated. The surface hydrophobicity, foaming capacity and emulsifying capacity of oxidized-SPI increased gradually at the initial stage with the increase of peracetic acid concentration. When the concentration of peracetic acid was increased up to 0.4%, compared with that of native SPI, the surface hydrophobicity, foaming capacity, emulsifying capacity and emulsifying stability of oxidized-SPI increased by 114.0, 81.4, 65.2, 49.8%, respectively, and achieved optimal results. However, excessive oxidation led to a decrease in surface hydrophobicity, foaming capacity and emulsifying stability of SPI, but it had no obvious effect on the foaming stability and emulsifying capacity of SPI. The foaming capacity, emulsifying capacity and emulsifying stability of SPI were positively related to the changes of surface hydroph...