Effect of mono- and dual frequency power ultrasound assisted enzymolysis on the degree of hydrolysis and ACE inhibitory activity of Stevia protein hydrolysates


 Purpose: To study the effects of ultrasound pretreatment at different frequencies and working modes, including mono frequency (MFU) dual-frequency (DFU), on degree hydrolysis (DH) angiotensin-I-converting enzyme (ACE) inhibitory effect Stevia protein (SP).
 Methods: Protein from leaves was extracted by water (50 g suspended in 1000 mL). The stevia extract (SPE) carried out using alcalase 5 % substrate (E/S) ratio. A then to investigate its microstructure morphology scanning electron microscopy (SEM).
 Results: results showed that did not increase DH SP significantly (p > 0.05). However, highest ACE activity hydrolysate obtained DFU level (20/50 KHz). Overall, ultrasonic mode had a significant influence activity.
 Conclusion: selection is essential for preparation peptide.