High hydrostatic pressure induced extraction and selective transfer of β-phosvitin from the egg yolk granule to plasma fractions

Egg yolk phosvitin is of particular interest due to its functional and biological properties. Recently, it was demonstrated that high hydrostatic pressure (HHP) (400 MPa for 5 min) induced the transfer of folic acid and phosvitin from the egg yolk granule to the plasma fraction. A granule fraction (G(in)) produced by egg yolk centrifugation was pressure-treated at 400 and 600 MPa for 5 and 10 min, and centrifuged to generate granule fractions (G(P1) in to G(P4)) and plasmas (P-P1 in to P-P4). Iron and phosphorus contents were also increased in P-P1 to P-P4 fractions, confirming the transfer of phosvitins from pressure-treated granule to plasma. Pressurization drastically improved phosvitin recovery in P-P fractions, specifically at 600 MPa for 10 min, which had the highest value of phosvitin/100 mg of dry plasma at 33.3 +/- 4.39 mg. Consequently, HHP represents an alternative approach for phosvitin transfer and recovery in the egg yolk soluble fraction.