Effect of dense-phase CO2 on polyphenoloxidase in model solutions

This paper was addressed to investigate polyphenoloxidase structural changes in model solutions upon inactivation by DP-CO2 treatments. Polyphenoloxidase was chosen as a typical example of an enzyme responsible for food quality decay. Mushroom polyphenoloxidase was exposed at room temperature for 5 min to DP-CO2 treatments at increasing pressure up to 12 MPa in order to obtain samples with decreasing residual activity. Samples having decreasing residual polyphenoloxidase activity were also prepared by thermal inactivation at 50 °C for up to 30 min. Molecular changes in polyphenoloxidase structure upon DP-CO2 and thermal inactivation were studied by HPLC gel permeation.