Preparation of soluble soybean protein aggregates (SSPA) from insoluble soybean protein concentrates (SPC) and its functional properties

Soluble soybean protein aggregate (SSPA) was efficiently prepared from alcohol-washed insoluble soybean protein concentrate (SPC) by the method of hydrothermal cooking (HTC) with high pressure homogenization and evaluated by differential scanning calorimetry (DSC), SDS-PAGE, gel filtration chromatography and texture analyzer. The conditions of low ionic strength and low concentration of protein (<5%) at pH 9.0 were found to be more suitable for the preparation of SSPA. DSC analysis showed that low temperature short time (LTST) HTC induced partial denaturation of protein aggregates while high temperature long time (HTLT) HTC induced fully denatured protein aggregates. Significant differences were observed between HTC–LTST and HTC–HTLT with respect to solubility, hydrophobicity, apparent viscosity, emulsion properties, foaming stability and gel strength. The most effective method for preparation of SSPA was HTC–LTST. SSPA prepared with this method showed higher hydrophobicity. SSPA has practical significance for the researchers working in the field of soy protein.