Assessment of the Effects of Acid-Adaptation on the Thermal Tolerance of Listeria monocytogenes and Salmonella Heidelberg by

........................................................................................................................... II ACKNOLEDGEMENTS ..................................................................................................... III LIST OF TABLES ................................................................................................................ VI LIST OF FIGURES ............................................................................................................ VII CHAPTER 1: INTRODUCTION .......................................................................................... 8 CHAPTER 2: LITERATURE REVIEW ............................................................................ 11 2.1.1. SALMONELLA AS A FOODBORNE PATHOGEN ................................................ 11 2.1.2. SOURCES AND TRANSMISSION OF SALMONELLA SPP. ................................ 12 2.1.3. SYMPTOMS AND CHARACTERISTICS OF SALMONELLOSIS ...................... 14 2.1.4. THERMAL TOLERANCE OF SALMONELLA SPP. .............................................. 15 2.1.5. ACID TOLERANCE OF SALMONELLA SPP. ....................................................... 17 2.1.6. FOOD SAFETY GOALS FOR SALMONELLA SPP. IN POULTRY MEAT ......... 18 2.2.1. LISTERIA SPP. AS A FOODBORNE PATHOGEN ................................................ 19 2.2.2. SOURCES AND TRANSMISSION OF LISTERIA SPP. ........................................ 20 2.2.3. SYMPTOMS AND CHARACTERISITCS OF LISTERIOSIS ............................... 22 2.2.4. THERMAL RESISTANCE OF LISTERIA SPP. ...................................................... 24 2.2.5. ACID TOLERANCE OF LISTERIA SPP. ................................................................ 26 2.2.6 FOOD SAFETY GOALS FOR LISTERIA SPP. ....................................................... 28 2.3 REFERENCES ............................................................................................................. 29 CHAPTER 3: ACID-ADAPTATION OF SALMONELLA HEIDELBERG REDUCES THERMAL TOLERANCE IN NOT-READY-TO-EAT GROUND TURKEY MEAT DURING REFRIGERATED STORAGE ........................................................................... 43 3.1 ABSTRACT .................................................................................................................. 43 3.2 INTRODUCTION ........................................................................................................ 44 3.3 MATERIALS AND METHODS .................................................................................. 47 3.4 RESULTS ..................................................................................................................... 50 3.5 DISCUSSION ............................................................................................................... 51 3.6 REFERENCES ............................................................................................................. 54