Abstract:

Soy protein isolate was phys. (heat pretreatment) and chem. (urea, guanidine-HCl, and cleavage of SS bonds) modified in order to dissoc. subunits, unfold the protein, and improve surface properties: hydrophobicity, emulsification capability, and stability. Heat pretreatment as well as chem. treatment with urea or guanidine-HCl or redn. of disulfide bonds, will improve emulsification performance in comparison to native soy protein isolate. Significant differences in redn. of surface tension of water in the presence of native and modified proteins were obsd. (45 and 35 dynes/cm, resp.). Measurements of fluorescence indicated that the relative hydrophobicity of the soy protein was also improved (from 600 to 1360) after heat pretreatment or contacting the soy protein with an 8M urea soln. [on SciFinder(R)]