Influence of stabilizing bonds on the texture properties of high-pressure-induced whey protein gels

High-pressure-induced gel formation of whey protein isolate (WPI, 15% protein) was studied at an operating pressure of 600 MPa, a temperature of 30degreesC and pressure holding times between 0 and 30 min. Stable gels were formed at each pressure treatment. Beyond the stabilizing molecular interactions disulfide bonds dominated in the formed gels, detected by means of an extraction test applying different buffer systems. The content of native whey protein fractions alpha-lactalbumin, beta-lactoglobulin A and B decreased and the amount of intermolecular disulfide bonds increased with prolonged pressure holding time. The gels became both stronger and more elastic with increasing holding time. Finally, combining the observations it comes up that the amount of stabilizing disulfide bonds directly influences the texture properties of high-pressure-induced whey protein gels. (C) 2003 Elsevier Ltd. All rights reserved.