Effects of sonication and high-pressure carbon dioxide processing on enzymatic hydrolysis of egg white proteins

Abstract

The objectives of this study were to examine the effect of sonication and high-pressure carbon dioxide processing on proteolytic hydrolysis of egg white proteins and antioxidant activity of the obtained hydrolysates. It appeared that the ultrasound pretreatment resulted in an increase in the degree of hydrolysis of the enzymatic reaction while the high-pressure carbon dioxide processing showed an inhibition effect on the enzymatic hydrolysis of egg white proteins to some extent. The antioxidant activity of the obtained hydrolysates was improved by ultrasound pretreatment of egg white proteins at the pH 8.3. Thus, the combination of ultrasound pretreatment at the pH 8.3 and subsequent enzymatic hydrolysis with alcalase at 50°C and pH 8.0 could offer a new approach to the improvement of the functional properties of egg white proteins and their biological activity. [Projekat Ministarstva nauke Republike Srbije, br. E!6750

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

“…The weakened interactions and structure of the protein after ultrasound treatment may expose more hydrolysis sites for enzyme action causing an increase in degree of hydrolysis and bioactivity. For example, ultrasound pretreatment of milk proteins showed an increased degree of hydrolysis and ACE inhibitory activity, when different enzymes were employed while in egg white proteins, there was increased antioxidant activity after ultrasound pretreatment and alcalase hydrolysis but only improved the ACE inhibitory activity of ovatransferrin when thermolysin was used for hydrolysis . In wheat germ proteins, ultrasound pretreatment improved the ACE inhibitory activity of alcalase hydrolysates …”

Production of Antioxidant Egg White Hydrolysates in a Continuous Stirred Tank Enzyme Reactor Coupled with Membrane Separation Unit

“…The EWPs are recognized as the second most extensive source of the allergenic reactions, where the main allergens are ovomucoid (OM), ovalbumin (OVA), ovotransferrin (OVT), and lysozyme (LYS) (Martos et al 2013). Enzymatic hydrolysis of EWPs has shown a great potential to improve their functional properties and biological properties and to reduce the protein allergenicity, while retaining their nutrition value (Knežević-Jugović et al 2012). The high selectivity and mild reaction conditions associated with the enzymatic process have made this approach an attractive alternative in the production of a high-value protein hydrolysate with added functional and health benefit, which are often difficult to obtain by conventional chemical (acid or alkali) route and thermal processing.…”

Impact of ultrasound on egg white proteins as a pretreatment for functional hydrolysates production

“…The effect of substrate pH during the ultrasound pretreatment on enzymatic hydrolysis It is widely recognized that changes of the pH value of substrate solution can cause denaturation of proteins by changing the charge distribution and conformation of the molecules and facilitates the accessibility of proteases to the inner peptide bonds [28]. Therefore, the influence of the pH of EWP solution during the ultrasound pretreatment prior to hydrolysis has been tested.…”

“…Enzymatic hydrolyses were carried out in a 600-mL mechanically stirred batch reactor with temperature and pH control by using three enzymes separately, namely Alcalase, Neutrase and papain according to the previously published protocol with slight modification [28]. The substrate for enzymatic hydrolysis was 10 % (w/w) aqueous solution of untreated or pretreated egg white (11.9 mg/mL, protein content determined according to the standard Kjeldahl method, N × 6.25) which was adjusted to optimum pH for particular enzyme activity with 2 M HCl or 2 M NaOH, then stirred and allowed to equilibrate to the working temperature for 15 min (typically 50 °C).…”

“…Despite the promising effects of sonication alone or in combination with heat or pressure on a laboratory scale, there is limited information on the hydrolysis of EWPs from different ultrasound treatments and proteolytic enzyme systems. Few studies have been carried out on the effect of ultrasound on functional properties of EWPs including surface hydrophobicity, concentration of sulfhydryl (SH) groups, gelation temperature, bulk viscosity, foaming and emulsifying properties, but research on impact of ultrasound on enzymatic hydrolysis of EWPs and biological activity of hydrolysates is a rather scare [27,28].…”