Abstract: Objective: The effects of high pressure(HP) treatment parameters on horseradish peroxidase(HRP) activity was studied. Method: The experiments was carried out under the high hydrostatic pressure (0.1～500 MPa), temperature (20～60 ℃), dwell time (2～34 min) and pH7.0 of the enzymatic solution. Result: ① The pH7.0 of the enzymatic solution is optimal acidity, and HRP activity value is highest at environmental pressure(0.1MPa) and ambient temperature(20℃). ② The effect of compression is significant on HRP activity under the treatment temperature 40 ℃, dwell time 10min and pH7.0; HRP activity increases abnormally in treatment of about 100MPa, and decreases slowly above 400 MPa. ③ HRP activity decreases slowly under temperature of less than 40 ℃ at the pressure of 500MPa and dwell time of 10min pH7.0; Decreases rapidly with increase of temperature above 40 ℃. ④ HRP activity arrives at the least level after compression of 25 min, increases little with prolonging further time; Dwell time is not main factor affecting HRP activity in HP treatment. Conclusion: HP treatment remarkably influences HRP activity. The pressure, temperature and dwell time is remarkable factors in HP treatment on HRP.

Key words: ultra high pressure, mild heat, horseradish peroxidase, dwell time, pH