Ultrasound technique could produce new functional egg white proteins
The suggestions come from a new study that tested how different kinds of ultrasound pre-treatments of egg white protein (EWP) altered its susceptibility to enzymatic hydrolysis, before analysing the structural properties of the resulting EWP hydrolysates.
Writing in Food Chemistry, the Serbian research team reported that ultrasound pre-treatments appear to greatly improve the enzymatic hydrolysis of EWPs under different conditions when compared to other methods - adding that a combination of high intensity ultrasound pre-treatment and enzymatic hydrolysis of egg white proteins (EWPs) “has been shown to be an acceptable alternative for the development of new value-added EWP hydrolysates.”
“The illustrated results have obviously proved that ultrasound pre-treatments regardless of the type are beneficial for the enzymatic hydrolysis of EWPs in comparison to the thermal pre-treatment,” said the team, led by Jelena Jovanović from the University of Belgrade.
“[These] EWP hydrolysates are an attractive protein source in human nutrition, which may be used in products for special nutrition like defined formula, diets or ‘medical food’ as well as for protein fortification of food for general use,” they added.
Study details
Jovanović and her colleagues performed a series of experiments in which EWP was subjected to two different types of ultrasound pre-treatment (using either a probe-type sonicator and an ultrasound cleaning bath) before a series of hydrolytic reactions were carried out in a stirred tank reactor at different substrate concentrations, enzyme concentrations, and temperatures using either untreated, thermally treated, or the ultrasonic pre-treated EWPs.
They found that the apparent reaction rate constants for proteolysis (k2) were significantly higher for EWP pre-treated with probe-type sonicator, and ultrasound cleaning bath technologies (0.053, and 0.045 min−1 respectively) compared to those that were untreated or thermally treated (0.009 and 0.011−1 respectively).
“Ultrasound pre-treatment also decreases hydrolysis activation (Ea) and enzyme deactivation (Ed) energy, enthalpy (ΔH), and entropy (ΔS) of activation,” wrote the authors – adding that the content of sulfhydryl groups and ζ potential showed a significant increase for both applied ultrasound pre-treatments and that a reduction of particle size distribution are achieved, “providing some evidence that the ultrasound causes EWP structural changes affecting the proteolysis rate.”
Jovanović and her team commented that the results add to fundamental understanding of the impact of ultrasound pre-treatment on enzymatic hydrolysis of EWPs, which “could be useful to scale-up process from laboratory bench to industrial plant.”
Source: Food Chemistry
Published online ahead of print, doi: 10.1111/1750-3841.13503
“Ultrasound Pretreatment as an Useful Tool to Enhance Egg White Protein Hydrolysis: Kinetics, Reaction Model, and Thermodinamics”
Authors: Jelena R. Jovanović, et al
