Abstract

 
 
 
 Purpose: To study the effects of ultrasound pretreatment at different frequencies and working modes, including mono frequency ultrasound (MFU) and dual-frequency ultrasound (DFU), on the degree of hydrolysis (DH) and angiotensin-I-converting enzyme (ACE) inhibitory effect of Stevia protein (SP).
 Methods: Protein from Stevia leaves was extracted by water (50 g suspended in 1000 mL). The hydrolysis of stevia protein extract (SPE) was carried out using alcalase at 5 % enzyme substrate (E/S) ratio. A study was then carried out to investigate its microstructure and morphology using scanning electron microscopy (SEM).
 Results: The results showed that ultrasound pretreatment did not increase DH of SP significantly (p > 0.05). However, the highest ACE inhibitory activity of stevia protein hydrolysate was obtained at DFU level (20/50 KHz). Overall, ultrasonic frequency mode had a significant influence on ACE inhibitory activity.
 Conclusion: The frequency selection of ultrasound pretreatment of SP is essential for the preparation of ACE inhibitory peptide.
 
 
 
Highlights
IntroductionThe demand for protein has increased due to increase in global population [1]
In recent years, the demand for protein has increased due to increase in global population [1]
The molecular unfolding of the Stevia protein that affected by ultrasound increases its surface hydrophobicity, which enabled the release of angiotensin-I-converting enzyme (ACE) inhibitory peptides during the enzymatic hydrolysis
Summary
The demand for protein has increased due to increase in global population [1]. It is estimated that nearly 25% of the world population lack a suitable protein supply [2]. Stevia rebaudiana Bertoni, a herbal medicine belonging to the Asteraceae family originated from Latin America. It is growing widely in different countries including Japan, Korea, and China as a commercial plant [4]. Studies have shown that dried stevia extract is rich in flavonoids, green pigment, amino acids, and other essential nutrients.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
