Background: Phosvitin (PV) is a highly-phosphorylated metal-binding protein in egg yolk.
Phosphoserine clusters make PV resistant to enzymatic digestion, which might be nutritionally undesirable.
Objective: This study was designed to determine the effects of high hydrostatic pressure and enzymatic
hydrolysis (HHP-EH) on the antioxidant and anti-inflammatory properties of PV hydrolysates (PVHs).
Methods: PV was hydrolyzed by alcalase, elastase, savinase, thermolysin, and trypsin at 0.1, 50, and
100 MPa pressure levels. PVHs were evaluated for degree of hydrolysis, molecular weight distribution
patterns, antioxidant and anti-inflammatory properties in chemical and cellular models. The effect of
PVH on gene expression of pro-inflammatory cytokines (TNF-α and IL-1β) was also evaluated using
real time-PCR. The hydrolysate with most potent antioxidant and anti-inflammatory properties was subjected
to LC-MS/MS analysis to identify the peptide sequence.
Results: Hydrolysates produced at 100 MPa exhibited higher degree of hydrolysis and greater reducing
power and free radical scavenging activity compared to those obtained at atmospheric pressure. After
adjusting the phosphate content, alcalase- and trypsin-digested PVHs showed superior iron chelation
capacity (69-73%), regardless of pressure. Both alcalase- and trypsin-digested PVHs significantly inhibited
nitric oxide production by RAW264.7 macrophage cells. LPS-stimulated up-regulation of proinflammatory
cytokines was also suppressed by alcalase-digested PVH.
Conclusion: The HHP-EH method could play a promising role in the production of bioactive peptides
from hydrolysis-resistant proteins. HHP-assisted PVH may be useful in preparing a potential pharmaceutical
with antioxidant and anti-inflammatory properties.