Characterisation of Glucono-¿-lactone Induced Soy Protein Gelation

The purpose of this study was to conduct an investigation into the development of a soy cheese with acceptable texture. The effects of heat treatment, different oils/fat and reducing and non-reducing sugars on the soy protein isolate (SPI) and SPI curd were studied. The physico-chemical, biochemical and textural properties of three types of soy cheese were compared: (1) glucono-¿-lactone (GDL) induced, (2) bacterially fermented and (3) GDL-induced and fermented. The results indicate that the fermented-GDL-cheese had the most acceptable texture. Heat treatment of SPI at neutral pH caused it to denature partially and increased the storage modulus and hardness of subsequently GDL-induced gels. Subsequent heat treatment of the acidic gels further significantly enhanced the storage modulus and gel hardness. The SPI emulsion containing palm stearin showed higher emulsifying stability, emulsifying activity, protein adsorption and denaturation degree than the emulsions containing sunflower and soy oil at neutral pH.