EFFECTS OF NACL, SUCROSE, AND WATER-CONTENT ON THE SURVIVAL OF SALMONELLA-TYPHIMURIUM ON IRRADIATED PORK AND CHICKEN

We investigated the effects of water content, activity, sodium chlorid e (NaCl) and sucrose contents on the survival of Salmonella typhimuriu m ATCC 14028 in irradiated mechanically deboned chicken meat (MDCM) an d ground pork loin. The effects of NaCl and sucrose concentration were investigated by adding various amounts to MDCM or ground pork loin, o r by rehydrating freeze-dried ground pork loin with NaCl solutions wit h various degrees of saturation. The effects of water content were inv estigated by rehydrating freeze-dried ground pork loin with different quantities of water. Inoculated samples were irradiated at 5 degrees C in vacuo to various doses up to 6.0 kGy. Highly significant effects ( p < 0.01) of water content, water activity (a(w)) and NaCl content, bu t not of sucrose content, on the survival of S. tryphimurium were iden tified. The failure of sucrose to provide the same protection for S. t yphimurium in meat against radiation argues against reduced water acti vity being a primary mechanism of protection. The results indicate tha t the survival of foodborne pathogens on irradiated meats with reduced water content or increased NaCl levels may be greater than expected.