Effect of ultrasonic-assisted modification with alkaline protease on functional properties of peanut protein isolate

Peanut protein isolate was used as a raw material,and the effect of ultrasonic on the alkaline hydrolysis of peanut protein isolate was studied,the optimal conditions of the ultrasonic-assisted enzymatic modification were also identified.The result showed that ultrasonic did not change the trend of the hydrolysis of peanut protein solubility and the temperature,pH,substrate concentration,enzyme dosage,but peanut protein isolate solubility increased by 30.9%.The optimum conditions of ultrasonic-assisted enzymatic modification were as follows: substrate concentration 60 g/L,enzyme dosage 4%,reaction temperature 50℃,pH 8.0,ultrasonic power 200 W.After the ultrasonic-assisted enzymatic modification,the degree of hydrolysis,solubility,emulsifying,foaming capacity of peanut protein isolate increased by 40.6%,30.9%,58.8% and 85.9%,respectively,and the foam stability and emulsion stability reduced by 21.5% and 47.9%,respectively.