• acetic acid;
  • Escherichia coli;
  • foodborne pathogenic bacteria;
  • lactic acid;
  • pork;
  • supercritical carbon dioxide


Aims:  To evaluate the effectiveness of organic acids and supercritical carbon dioxide (SC-CO2) treatments as well as their combined effect for the reduction of nonpathogenic Escherichia coli and three pathogenic bacteria in fresh pork.

Methods and Results:  The different treatment conditions were as follows: (i) treatment with acetic (1%, 2% or 3%) or lactic acid (1%, 2% or 3%) only, (ii) treatment with SC-CO2 at 12 MPa and 35°C for 30 min only and (iii) treatment with 3% acetic or lactic acid followed by treatment with SC-CO2. Within the same organic acid concentration, the lactic and acetic acid treatments had similar reductions. For the combined treatment of lactic acid and SC-CO2, micro-organism levels were maximally reduced, ranging from 2·10 to 2·60 log CFU cm−2 (E. coli, 2·58 log CFU cm−2; Listeria monocytogenes, 2·60 log CFU cm−2; Salmonella typhimurium, 2·33 log CFU cm−2; E. coli O157:H7, 2·10 log CFU cm−2).

Conclusions:  The results of this study indicate that the combined treatments of SC-CO2 and organic acids were more effective at destroying foodborne pathogens than the treatments of SC-CO2 or organic acids alone.

Significance and Impact of the Study:  The combination treatment of SC-CO2 and organic acids may be useful in the meat industry to help increase microbial safety.