HEATING AND STORAGE-CONDITIONS AFFECT SURVIVAL AND RECOVERY OF LISTERIA-MONOCYTOGENES IN-GROUND PORK

The effect of heating rate, heating atmosphere, and meat age on surviv al of Listeria monocytogenes was examined in ground pork, as well as t he ability of injured cells to recover during storage under air and va cuum packaging at 4 and 30 degrees C. Significantly more survivors wer e observed when samples were heated at 1.3 degrees C/min than at 8.O d egrees C/ min. Cells inoculated into 3-month-old pork were more sensit ive to heating than cells inoculated into fresh ground pork (D-62 degr ees C = 5.2 min and 7.7 min, respectively). More survivors were detect ed when the meat was heated aerobically than anaerobically. However, s torage under vacuum at 4 or 30 degrees C resulted in faster recovery c ompared with cells packaged in air. Thus, heating and packaging condit ions affected ability of this pathogen to survive and recover after a heat process in pork.