Comparative Composition and Antioxidant Activity of Peptide Fractions Obtained by Ultrafiltration of Egg Yolk Protein Enzymatic Hydrolysates

Abstract

The objective of the study was to compare the antioxidant activity of two distinct hydrolysates and their peptide fractions prepared by ultrafiltration (UF) using membranes with molecular weight cut-off of 5 and 1 kDa. The hydrolysates were a delipidated egg yolk protein concentrate (EYP) intensively hydrolyzed with a combination of two bacterial proteases, and a phosphoproteins (PPP) extract partially hydrolyzed with trypsin. Antioxidant activity, as determined by the oxygen radical absorbance capacity (ORAC) assay, was low for EYP and PPP hydrolysates with values of 613.1 and 489.2 μM TE·g−1 protein, respectively. UF-fractionation of EYP hydrolysate increased slightly the antioxidant activity in permeate fractions (720.5–867.8 μM TE·g−1 protein). However, ORAC values were increased by more than 3-fold in UF-fractions prepared from PPP hydrolysate, which were enriched in peptides with molecular weight lower than 5 kDa. These UF-fractions were characterized by their lower N/P atomic ratio and higher phosphorus content compared to the same UF-fractions obtained from EYP-TH. They also contained high amounts of His, Met, Leu, and Phe, which are recognized as antioxidant amino acids, but also high content in Lys and Arg which both represent target amino acids of trypsin used for the hydrolysis of PPP.

Potential Therapeutic Applications ofMucuna pruriensPeptide Fractions Purified by High-Performance Liquid Chromatography as Angiotensin-Converting Enzyme Inhibitors, Antioxidants, Antithrombotic and Hypocholesterolemic Agents

“…In addition, ultrafiltration also can be used to perform peptide separation according to their molecular masses and charges. 25 The protein content was determined through filtrates and retentates. The highest protein content was observed in PF >10 kDa (1.813 mg/mL) and the lowest in PF <1 kDa (0.088 mg/mL).…”

Purification and Characterization of an Antioxidant Protein from Fertilized Eggs

“…During incubation, the antioxidant system was considerably advanced to protect the embryo from damaging effects of free radicals (Starrs et al , 2001). Some reported antioxidants, such as antioxidant vitamins and enzymes, dealt with oxidative stress at hatching time in different tissues (Chay et al , 2011; Mine et al , 2010; Wilson et al , 1992). In this study, proteins derived from fertilized eggs firstly exhibited antioxidant activity which increased during incubation significantly.…”

Egg proteins: fractionation, bioactive peptides and allergenicity

“…Depending on the different molecular size, gel‐permeation chromatography segregated proteins from defatted egg yolk fractions . But it is not suitable for industrial‐scale application, because of the fragile nature of gels used in gel‐permeation chromatography and possible interaction between gels and proteins . Therefore, ion‐exchange chromatography has been more widely used as a large‐scale method to separate charged proteins from egg yolk.…”

“…Surface properties of membranes, pH, and salt concentration are major factors in determining the success of protein fractionation . Ultrafiltration is considered as a preliminary step to remove enzymes, whereas nanofiltration with negatively charged membranes successfully gets rid of salts from protein fractions . Generally, a serial membrane filtration process includes dilution, filtration, delipidation by hydrophobic filters, and diafiltration to desalt and concentrate proteins .…”

“…Generally, a serial membrane filtration process includes dilution, filtration, delipidation by hydrophobic filters, and diafiltration to desalt and concentrate proteins . For instance, desalting of egg yolk proteins dominated by phosvitin was achieved using 10 000 and 30 000 Da molecular weight cut‐off polyethersulfone membranes …”