GROWTH, INJURY, AND SURVIVAL POTENTIAL OF YERSINIA-ENTEROCOLITICA, LISTERIA-MONOCYTOGENES, AND STAPHYLOCOCCUS-AUREUS IN BRINE CHILLER CONDITIONS

A model brine system was used to evaluate growth, injury, and survival potential of Yersinia enterocolitica, Listeria monocytogenes, and Sta phylococcus aureus. Each strain was incubated For up to 30 days at -12 to 28 degrees C In brain heart infusion broth containing 0.5 to 20% N aCl. Samples were enumerated on a dual agar plating system to assess g rowth and injury, Y. enterocolitica grew at -2 degrees C in 0.5% brine and at 5 degrees C in 5% NaCl. L. monocytogenes grew at 5 degrees C i n 5% NaCl and at 12 degrees C in 9% NaCl, S. aureus grew at 12 degrees C in 5% NaCl. Significant injury was observed for two of the pathogen s, but not for L. monocytogenes. Bacteriostatic or lethal conditions w ere maintained for the three organisms at -2 degrees C and 9% NaCl. Wh ile lethal NaCl and temperature combinations were defined for Y. enter ocolitica and S. aureus, L. monocytogenes survived for 30 days at -12 degrees C in 20% NaCl. This study provides safety criteria and recomme ndations for use in the operation of recycle brine systems for cooling processed foods.