The influence of pH, protein concentration, and ionic strength, on rheological properties of thermally treated acidic soy protein dispersions, was studied. Structural changes due to pH effect and thermal treatment were analized. DSC-thermograms at pH 3.5 showed a shoulder at 74.1160.168C that could be attributed to both b-conglycinin and the hexameric form of glycinin; and a peak at 81.8860.298C corresponding to 11S dodecameric form. At pH 2.75 one endotherm corresponded to denaturation of b-conglycinin. The acidic dispersions presented pseudoplastic behavior with h app values higher than those at pH 8.0. At pH 3.50 the h app was higher than at pH 2.75. The maximum viscoelasticiy was obtained with addition of 0.1 and 0.25M NaCl in the dispersions of pH 3.50 and 2.75, respectively. The increase in viscoelasticity was enhanced by the formation of 11S native fraction dimers.To prepare the acid isolates (pH 2.50, 2.75, 3.00, 3.25, and 3.50) and that at pH 8.0, the isoelectric precipitate was dispersed in distilled water and adjusted to the desired pH with either 2N HCl or 2N NaOH. Dispersions thus obtained were lyophilized.To determine the extent of influence of the pH treatment on protein denaturation, alkaline isolates previously modified by treatment at different pHs were also prepared. Different acid dispersions(pH 2.50-3.0) were prepared from the isoelectric precipitate, by adjusting the pH with 2N HCl; these dispersions were then kept at the corresponding pH for 1h at 20ЊC, and then adjusted to pH 8.0 with 2N NaOH prior to lyophilization. Preparation of 7S and 11S-enriched fractions