MECHANISM OF PHYSICAL MODIFICATION OF INSOLUBLE SOY PROTEIN-CONCENTRATE

The mechanism for solubilization of alcohol-leached soy protein concen trate (ALSPC) by physical modification was studied from the standpoint of molecular interactions, which are related to the differences in pr otein solubility under different conditions. The low solubility of ALS PC is caused by both noncovalent and covalent forces, but the noncoval ent forces do not affect the solubility of modified soy protein concen trate (MSPC). Gel filtration shows that the major constituents of solu ble protein from ALSPC and MSPC are protein molecules and protein aggr egates, respectively. Physical modification promotes the formation of aggregates that are readily soluble in buffer. Fluorescence spectrosco py further proved that the hydrophobic groups are located in the inter ior of the aggregates. The reason for the formation of soluble protein aggregates during physical modification of ALSPC is discussed.