Superficial properties of soy protein 7S and 11S at low pH

Based on the conditions of 7S forming fibril,the emulsifying and foaming properties of soy protein 7S and11S( including acidic and basic subunits) was investigated under prolonged heat treatment at low p H. The results showed that the foaming properties of different soy protein components were significantly improved( p < 0.05),while the emulsification was not sigificantly regular changed even the emulsion stability was reduced by heating treatment at low p H. There were no relationships between the fibrillar aggregates and modified properties.Compared with the heating treatment at p H7.0,the surface hydrophobicities of soy protein 7S and 11 S were significantly increased under heating treatment at low p H,and the special structure with high surface hydrophobicities was benefit for improving foaming properties of soy protein. Then,the surface hydrophobicities and foaming properties of 7S and 11 S were improved significantly after prolonged heat treatment at low p H.