Inactivation curves of Escherichia coli under high carbon dioxide pressures
(2.5, 5.1, 7.6 and 10.1 MPa) at different temperatures (20, 30, 40 and 45
degreesC) were analyzed using the modified Gompertz model. The phase disapp
earance (time for complete inactivation of all cells, lambda) and the inact
ivation rate (mu) of E. coli were inversely related. Inactivation rates (mu
) of E. coli were higher at 45 degreesC under 10.1 MPa CO2 pressure than at
25, 30 and 40 degreesC under 2.5, 5.1 and 7.6 MPa CO2 pressure. Increased
pressure and temperature had significant effects on the survival of E. coli
. The temperature dependence of the inactivation rate constant was analyzed
based on the Arrhenius, linear and square-root models. The temperature sen
sitivity (high Ed determined based on the Arrhenius model was higher at hig
h temperatures. E-mu (activation energy) value was -186.56 Kjoule/mol at 10
.1 Mpa, and -137.24, -167.25 and -183.80 Kjoule/mol at 2.5, 5.1 and 7.6 MPa
, respectively. Results of this study enable the prediction of microbial in
activation exposed to different CO2 pressures and temperatures.