Denaturation of α-lactalbumin and bovine serum albumin in pressure-treated reconstituted skim milk

Abstract

The kinetics of α-lactalbumin and bovine serum albumin (BSA) denaturation in pressure-treated reconstituted skim milk samples at pressures of 100–800 MPa and temperatures of 10–40 °C was studied. No denaturation was observed at pressures up to 400 MPa, whereas at 500 MPa or higher, the level of denaturation increased with increasing holding time at each pressure/temperature, with increasing pressure at each holding time/temperature or with temperature at each pressure/holding time. BSA denatured at a faster rate than α-lactalbumin, and denaturation for both proteins could be described as second order. Evaluation of the kinetic and thermodynamic parameters suggested that α-lactalbumin denaturation was an aggregation-limited reaction, whereas for BSA, the denaturation transitioned from aggregation-limited to unfolding-limited as the pressure increased.

Keywords

• α-lactalbumin
• Bovine serum albumin
• Milk
• Denaturation
• High pressure