Effect of high hydrostatic pressure on the enzymic hydrolysis of beta-lactoglobulin B by trypsin, thermolysin and pepsin.
Hydrolysis of beta-lactoglobulin B (beta-lg B) by pepsin, a process slow at ambient conditions, is facilitated at a moderately high hydrostatic pressure such as 300 MPa, corresponding to an apparent volume of activation delta V# = -63 ml mol-1 at pH 2.5, 30 degrees C and gamma/2 = 0.16. Digestion of beta-lg by trypsin and thermolysin is likewise enhanced by pressure, and the pressure effect has been traced to pressure denaturation of beta-lg B, which by high-pressure fluorescence spectroscopy has been shown to have a large negative volume of reaction, delta V(o) = -98 ml mol-1, at pH 6.7, 30 degrees C and gamma/2 = 0.16. Pressure denaturation is only slowly reversed following release of pressure and the enhanced digestibility is maintained at ambient pressure for several hours.
Stapelfeldt
H
H
Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
Petersen
P H
PH
Kristiansen
K R
KR
Qvist
K B
KB
Skibsted
L H
LH
D006868:Hydrolysis; D006874:Hydrostatic Pressure; D007782:Lactoglobulins / Q000378:metabolism*; D010434:Pepsin A / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013820:Thermolysin / Q000378:metabolism*; D014357:Trypsin / Q000378:metabolism*
D007782:Lactoglobulins; D014357:Trypsin; D010434:Pepsin A; D013820:Thermolysin