Effect of pretreatment with sweeping frequency ultrasound on zymohydrolysis characteristic of zein

In order to explore the effect of sweeping frequency ultrasound (SFU) promoting zymohydrolysis reaction, improve the relative inhibitory activity (RIA) of hydrolysate to Angiotensin-I-Converting Enzyme (ACE) , the SFU was used to treat zein.The One-factorial experiments were taked to search the best operating mode of SFU, pretreatment parameters of ultrasound and the optimal conditions of hydrolysis.With the optimal conditions of ultrasonic pretreatment and hydrolysis, we could find out that ACE inhibitory activity was 48.48%, DH was 11.20% .The IC 50 value of hydrolysate was 3.77mg/mL, it decreased by 31.20%, compared with traditional enzymatic hydrolysis (without ultrasound treatment) .The yield of product was 66.15%, compared with traditional enzymatic hydrolysis, it improved by 14.39% .These results proved that SFU could effectively promoted enzymatic hydrolysis of zein, and improved RIA of hydrolysate to ACE.