Optimization of some conditions of Neutrase-catalyzed plastein reaction to mediate ACE-inhibitory activity in vitro of casein hydrolysate prepared by Neutrase

Abstract

Casein hydrolysate was prepared by hydrolyzing casein with Neutrase and then modified by a Neutrasecatalyzed plastein reaction. The prepared hydrolysate had a degree of hydrolysis of 13.0% and exhibited ACE inhibition in vitro with an IC 50 value of 40.4 μg⋅mL −1 . With the decreased amount of free amino groups of the modified hydrolysate as the response, some conditions of the plastein reaction including substrate concentration, enzyme to substrate ratio, reaction temperature and time were studied by single factor experiments and response surface methodology, and optimized finally as 62% (w/w), 3.0 kU⋅g −1 peptides, 30°C and 6.3 h, respectively. The maximum decreased amount of free amino groups of the modified hydrolysate prepared under these optimized conditions was 210.0 μmol⋅g −1 peptides, while corresponding IC 50 value was lowered to 14.7 μg⋅mL −1 . The present result indicates that Neutrase-catalyzed plastein reaction was capable of enhancing ACE-inhibitory activity in vitro of casein hydrolysate, and also highlights the importance of a forthcoming study to investigate the peptide compositions of the modified hydrolysate and the role of protease used in the plastein reaction.

Antihypertensive activities of the plasteins derived from casein hydrolysates in spontaneously hypertensive rats

“…This indicated that the applied plastein reaction conferred CHPRO and CHPHE with higher in vitro ACEI activities. This result was consistent with those previously reported results (Li et al, 2010;Sun & Zhao, 2012;Xu et al, 2014;Zhao & Li, 2009), proving again that the plastein reaction could enhance in vitro ACEI activities of protein hydrolysates.…”

“…Transpeptidation occurred in the plastein reaction is considered very important to the enhanced activities (Li, Li, & Zhao, 2010;Udenigwe & Rajendran, 2016). Casein and soy protein hydrolysates after their plastein reaction thus show increased in vitro ACEI activities (Gao & Zhao, 2012;Sun & Zhao, 2012;Xu, Kong, & Zhao, 2014;Xu, Li, & Zhao, 2013;Zhao & Li, 2009). In the presence of some hydrophobic amino acids, in vitro ACEI activities of casein hydrolysates can also be enhanced by the plastein reaction (Li et al, 2010).…”

ACE inhibitory activity of pangasius catfish (Pangasius sutchi) skin and bone gelatin hydrolysate

“…Based on the results of the previous studies, ACE inhibitory activity of peptides increased with prolonged incubation with enzyme. However, longer hydrolysis time led to the peptides lost their ability to inhibit ACE (Wu et al 2008;Xu et al 2011). …”

Effect of power ultrasound pretreatment on peptidic profiles and angiotensin converting enzyme inhibition of milk protein concentrate hydrolysates

“…In this study, ultrasound was applied as a pretreatment method before the enzyme hydrolysis of MPC with Neutrase in order to study the peptidic profiles of the resulting hydrolysates and link them to the improvement in the angiotensin converting enzyme (ACE) inhibiting activity of the hydrolysates. Neutrase, an endoprotease, has been recommended in several studies for the production of ACE inhibiting hydrolysates . In a recent study involving five different proteases, Neutrase showed the highest potential to generate ACE inhibitory peptides from MPC …”

“…Neutrase, an endoprotease, has been recommended in several studies for the production of ACE inhibiting hydrolysates. 18,19 In a recent study involving five different proteases, Neutrase showed the highest potential to generate ACE inhibitory peptides from MPC. 13…”