Effect of microfluidization and ultrasonic on solubility of soybean protein isolate

The solubility of soybean protein isolate ( SPI) decreased gradually with extension of storage time at room temperature.The content of soluble protein reduced from 59.5% ± 1.2% to 43.3% ± 1.6% , when the storage time up to 360d.Size and turbidity of SPI showed that aggregation didn’t stead to the dissolution with extension of storage time.The proportion of soluble SPI increased 88.1% ± 1.3% by used microfluidization and ultrasonic. In addition, SDS-PAGE and SEC-HPLC showed that the changes of subunits conducive to improve solubility of SPI after microfluidization and ultrasonic treatment. Distribution of SPI aggregation size became small and narrower after microfluidization and ultrasonic treatment.Turbidity of different supernatants all decreased sharply.