Effect of carbon dioxide pressure on Listeria monocytogenes in physiological saline and foods

The effect of 15,30 and 60 atm CO2 pressure at 25,35 and 45 degrees C on Listeria monocytogenes was studied. A biphasic curve was observed in the CO2 treatments. A primary curve was characterized with very little killing and a secondary curve was showed straight-line inactivation kinetics. An increase of pressure and/or temperature enhanced the antimicrobial effects of CO2. Listeria monocytogenes suspended in physiological saline containing 1% brain-heart infusion broth was completely inactivated under 60 atm CO2 treatment in 115, 75 and 60 min at 25 35 and 45 degrees C, drespectively! A minimum D-value was obtained under 60 atm CO;, pressure at 45 degrees C. High pressure CO2 treatment technique can possibly be applied to reduce microbiol load in whole and skim milk;and carrot, orange, peach, and apple juices (C) 2000 Academic Press.