Effects of high-pressure processing and enzymatic dephosphorylation on phosvitin properties.
BACKGROUND
Egg phosvitin could be a good source of functional peptides. Enzymatic dephosphorylation and high-pressure processing combined with thermal treatment applied before proteolysis could produce phosvitin hydrolysates with different properties compared to its native form.


RESULTS
Phosvitin structure was maintained overall during high-pressure treatment of 600 MPa applied at an initial temperature of 65 °C regardless of the pH and duration of treatment, confirming the high structural stability of this phosphoprotein. Treatment of phosvitin with phosphatase increased the degree of dephosphorylation from 24% to 63%, after 2 and 18 h, respectively. Moderate dephosphorylation of phosvitin prior to proteolytic digestion improved its hydrolysis, allowing formation of peptides with a molecular weight lower than 17,000 kDa as determined by size exclusion chromatography. Angiotensin-converting enzyme (ACE) inhibition and antioxidant activity of dephosphorylated and protease-treated phosvitin was increased by 52% and 39%, respectively, as compared to protease-digested native phosvitin.


CONCLUSIONS
Enzymatic dephosphorylation before proteolysis mimicking in vivo gut conditions improved ACE inhibition and antioxidant activity of phosvitin hydrolysates.
Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011-1061, USA.
Stephanie P
SP
Volk
Dong U
DU
Ahn
Michael
M
Zeece
Stephanie
S
Jung
D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000975:Antioxidants / Q000494:pharmacology; D002942:Circular Dichroism; D004530:Egg Yolk / Q000737:chemistry; D006358:Hot Temperature; D010447:Peptide Hydrolases / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification; D010710:Phosphates / Q000378:metabolism; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D010766:Phosphorylation; D010774:Phosvitin / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D011312:Pressure
D000806:Angiotensin-Converting Enzyme Inhibitors; D000975:Antioxidants; D010455:Peptides; D010710:Phosphates; D010774:Phosvitin; D010744:Phosphoric Monoester Hydrolases; D010447:Peptide Hydrolases