Kinetic Analysis of Yeast Inactivation by High Pressure Treatment at Low Temperatures

Abstract

Inactivation of Saccharomyces cerevisiae by high pressure treatment from 120 to 300 MPa in the range of -20 to 50 degrees C followed pseudo first order reaction kinetics. The regression analysis of 43 inactivation rates showed that pressurization at sub-zero temperatures (-20 and -10 degrees C) enhanced the effects of pressure as pressurization at higher temperatures: i.e., pressurization at 190 MPa and -20 degrees C gave the same effect as pressurization at 320 MPa and room temperature. The results imply that high pressure treatment applied to food sterilization at lower temperatures has a greater effect with smaller pressure without destroying the original taste and flavor. Additional effects of sugars and salts on inactivation of yeast are also described.