Functionality, ACE ‐Inhibitory Activities and Antioxidant Activity of Whey Protein: Effects of Simultaneous Dual Frequency Ultrasound Pretreatment

ABSTRACT There is high demand for food proteins with enhanced functional qualities and bioactive characteristics developed through safe technologies. The hydrolysate of whey protein isolate (WPI) was subjected to simultaneous dual frequency energy‐gathered ultrasound (SDFU) pretreatment, and its functionality, antioxidant activity and ACE‐inhibitory activities evaluated. The results showed that ultrasound pretreatment significantly ( p < 0.05) increased the protein functionalities (solubility, emulsion stability index and emulsion ability index) with the highest improvement being recorded at 20 min of sonication. Antioxidant activity of ultrasound pretreated whey hydrolysate was improved after 1 h of hydrolysis using trypsin. The optimal ACE‐inhibitory activity of 92.34% was achieved at optimal conditions of 15% concentration, temperature of 46°C, enzyme substrate ratio of 2000 U/g and pH of 8.06 using response surface design. SDFU can be used as pretreatment technique to improve the functionality, antioxidant and ACE‐inhibitory activities of WPI.