APPLICATION OF SUPERCRITICAL CARBON DIOXIDE FOR MICROORGANISM REDUCTIONS IN FRESH PORK

This study was conducted to examine the inhibitory effects of supercritical carbon dioxide (SC-CO2) on microorganisms in fresh pork. With SC-CO2 treatment at 120 bar and 40C for 30 min, the initial mesophilic plate counts were reduced from 6.23 to 4.54 log colony-forming units (cfu) per cm(2), and the reduction levels of microorganisms, including nonpathogenic Escherichia coli, Listeria monocytogenes, Salmonella Typhimurium and E. coli O157:H7, ranged from 1.99 to 2.51 log cfu/cm(2). Even though SC-CO2 treatment at 120 bar resulted in higher reductions than treatment at 80 bar, the higher temperature or longer exposure times did not always present greater inhibitory effects than the lower temperature or shorter exposure times. Therefore, from an economic point of view, SC-CO2 treatment at the lower temperature (35 versus 40C) and shortest exposure time (10 versus 30 min) was more efficient than treatment at the higher temperature or longer exposure time at the same pressure.