Effect of heat treatment on functional properties of soybean protein isolate

The effects of heat treatment on the functional properties of soy protein isolate (SPI) were studied SPI dispersions (2% ,W ∶ V) ( pH 7. 0) were heated at 80,90,100 ℃ for 15,30,60,100,180 min respectively. The properties of heated SPI,such as solubility,emulsifying and foaming properties,surface hydrophobic,degree of protein denaturation and molecular weight distribution,were determined respectively. The results showed that the properties of 2% SPI were almost not affected by the heat treatment at 80 ℃ except the emulsify stability which was slightly decreased after heating. After heating at 90,100 ℃ for 1 h,the foaming capacity of 2% SPI was increased significantly while the foaming stability and emulsifying properties were decreased remarkably. The solubility of SPI was improved after heat treated at high temperature for short time. Furthermore,the correlation revealed the foaming capacity and the solubility are moderately significant correlated.