Two kinds of soluble aggregates, HC-SPI and HT-SPI, were obtained through centrifugation at 10000 g for 10 min, from two modified soy protein isolates, which were mediated by hydrothermal cooking at 121 °C (0.1 MPa, gauge pressure) for 30 min in an autoclave and by moisture heat treatment at 90 °C for 30 min in a water bath, respectively. The physicochemical and conformational properties, including SDS-PAGE/GPC, surface charge and hydrophobicity, free sulfhydryl group (SH) contents and

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... bond (SS) contents, as well as secondary and tertiary conformations, were evaluated. Remarkable differences in SDS-PAGE patterns, GPC profiles, surface charge and hydrophobicity, free sulfhydryl group (SH) and disulfide bond (SS) contents, tertiary and quaternary conformations were observed between HC-SPI and HT-SPI. The significantly different free sulfhydryl group (SH) contents between HC-SPI and HT-SPI (especially as compared to N-SPI) suggest discrepancy in S-S formation mechanism. Both of the tertiary and quaternary conformations showed varying exposure extent with varying aromatic residues (Phe, Tyr and Trp).These results suggested good relationships between the physicochemical properties and conformational features of these soluble aggregates from SPI.