The combined effects of pressure and temperature on the activity of carrot peroxidase (POD) were investigated in the pressure range 0.1-600 MPa and the temperature range 25-45degreesC. At lower pressures (<396 MPa), carrot POD stability increased compared to unpressurized samples. Inactivation of 91% was obtained at 600 MPa and 45degreesC. High hydrostatic pressure (HHP) combined with temperature treatment enhanced the inactivation of carrot POD. Regeneration of POD activity with the combined HHP and temperature treatments followed first order kinetics at 25, 35 and 40degreesC. Regeneration was not observed at 506 MPa and 45degreesC. HHP had no significant effect on the loss of vitamin C or on protein content. HHP combined with mild heat treatment was found to be better than the thermal treatment at high temperatures for inactivation of POD in carrot processing.