MODELING THE THERMAL INACTIVATION OF SALMONELLA-TYPHIMURIUM USING BIOLUMINESCENCE DATA

Inactivation of micro-organisms by heat is a tradition food processing technique used to reduce or eliminate the microbial load in foods thu s preventing bacterial associated disease and food spoilage. Models of thermal death kinetics are routinely used to predict the amount of he at required but such models are limited by the acquisition of accurate thermal death data for bacteria in situ and in complex microflora. In vivo bioluminescence from lux recombinant bacteria is an important al ternative to traditional plate counts for examining bacterial injury a nd stress but the thermal instability of luciferase has appeared to pr eclude its application in heating studies. We have developed a procedu re which overcomes the thermal instability of luciferase and demonstra te that computer generated models of the thermal injury of Salmonella typhimurium show equivalence between bioluminescence and viable count data.