Influence factors of foaming properties and emulsifying properties of soybean protein isolate

The foaming properties and the emulsification capability of soybean protein isolate(SPI) were closely related to protein content, NaCl content, carrageenan content, sucrose content, potassium sorbate content, pH, heating temperature and so on. The emulsification capability and foaming properties of SPI reached the maximum when the protein content was 2.0g/100ml and 2.5g/100ml, respectively. The pH far from 4.5, the emulsifying properties and foaming properties increased. When the heating temperature was 45℃, the emulsifying property was the best and the foaming property was the worst. The optimum formula for SPI was NaCl 1.00g/100ml, carrageenan 0.2g/100ml, and potassium sorbate 0.08g/100ml, under such condition, the emulsifying properties and foaming properties were the best. Sucrose addition could decrease the foaming properties of SPI. However, 6.0g/100ml addition of sucrose could evidently improve the emulsifying properties of SPI.