Antimicrobial effect of pressurised carbon dioxide on Enterococcus faecalis in physiological saline and foods

Inactivation of Enterococcus faecalis by high-pressure CO2 was investigated in a batch system. Two phases were observed in the survival curves. The ea rlier stage was characterised by a slow rate of decrease in the number of E faecalis. This rate increased sharply at the later stage. Enterococcus fae calis suspended in physiological saline was completely inactivated under 6. 05 and 3.02 MPa CO2 treatment in 18 and 80 min respectively at 35 degrees C . The high pressure of CO2 at 45 degrees C was effective at sterilising ora nge, peach and carrot juices but ineffective for whole and skimmed milk. A minimum D-value was obtained under 6.05 MPa CO2-pressure at 45 degrees C. R eduction rates of E faecalis were sensitive to pressure, temperature, expos ure time, the initial number of cells and the suspending medium. (C) 2000 S ociety of Chemical Industry.