Denaturation of β-lactoglobulin in pressure-treated skim milk

The kinetics of β-lactoglobulin (β-LG) denaturation in pressure-treated reconstituted skim milk samples over a wide pressurization range (100−600 MPa) and at various temperatures (10−40 °C) was studied. Denaturation was extremely dependent on the pressure and duration of treatment. At 100 MPa, no denaturation was observed regardless of the temperature or the holding time. At higher pressures, the level of denaturation increased with an increasing holding time at a constant pressure or with increasing pressure at a constant holding time. At 200 MPa, there was only a small effect of changing the temperature at pressurization. However, at higher pressures, increasing the temperature from 10 to 40 °C markedly increased the rate of denaturation. The two major genetic variants of β-LG (A and B) behaved similarly to pressure treatment, although the B variant appeared to denature slightly faster than the A variant at low pressures (≤400 MPa). The denaturation could be described as a second-order process for both ...