The influence of dissolved CO(2) concentration on the death kinetics of Saccharomyces cerevisiae.
OBJECTIVE
The effects of temperature and concentration of dissolved CO(2) on the inactivation of Saccharomyces cerevisiae were investigated using a plug-flow system.


RESULTS
Several combinations of pressure (4, 6, 8, 10 mega-Pa (MPa)) and temperature (30, 34, 36, 38 degrees C) were used. The D-values obtained were 0.14 min at 8 MPa and 38 degrees C, and 0.15 min at 10 MPa and 36 degrees C. The log D-values were related linearly to the treatment temperature and to the dissolved CO(2) concentration. The thermal resistance constant (zCO(2)(T)) was 9.5 degrees C in the media, including significant levels of CO(2), and the CO(2) resistance constant was z(temp.)(gamma)=7.2 gamma.


CONCLUSIONS
This work has shown that inactivation followed first-order death kinetics, and the effects of temperature and CO(2) concentration were consistent through the critical temperature and pressure of CO(2). Therefore, it is feasible to estimate D-values at any temperature and any CO(2) concentration.


CONCLUSIONS
Non-thermal inactivation of micro-organisms in acidic beverages could be realized by the present technique.
Shimoda
M
M
Department of Bioscience and Biotechnology, Kyushu University, Fukuoka, Kyushu, Japan. mishimoda@agr.kyushu-u.ac.jp
Cocunubo-Castellanos
J
J
Kago
H
H
Miyake
M
M
Osajima
Y
Y
Hayakawa
I
I
D002245:Carbon Dioxide / Q000378:metabolism / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D005519:Food Preservation / Q000379:methods*; D007700:Kinetics; D009997:Osmotic Pressure; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D013696:Temperature
D002245:Carbon Dioxide