Factors affecting the solubility and emulsifying property of soy protein isolate

The effects of pH,concentration of SPI and NaCl,stirring duration and temperature on the solubility and emulsifying property of soybean protein isolate(SPI) were studied.The results showed that when concentration of SPI was 0.8% and pH 6.0,the solubility and emulsifying property of SPI reduced within the selected concentrations of NaCl,while enhanced prominently with longer stirring duration and hoist temperature.In room temperature,the maximum solubility,1070.7 μg/mL,was reached when stirring for 50 min,which was 1.5 times of that(696.7μg/mL) of untreated SPI.The maximum emulsifying property,24.3 mL/g,was reached when stirring for 10 min,which was 1.6 times of that(15.5mL/g) of untreated SPI.When heated to 60 ℃,the solubility and emulsifying property reached to maximums,1100 μg/mL and 33.8 mL/g,which were 1.6 times and 2.2 times of those of untreated SPI.This research provides a theoretical basis for the application of SPI in food processing industry.