THERMAL-DESTRUCTION OF ESCHERICHIA-COLI O157-H7 IN HAMBURGER

The inactivation of E. coli 0157:H7 in ground beef patties cooked in a skillet was investigated. Ground beef patties inoculated with a mixtu re of five strains of E. coli 0157:H7 were cooked in a Farberware skil let set at a temperature of 275 degrees F (137 degrees C). Eight type K thermocouples connected to a data logger were used to record the tem peratures at eight points within the patty. The cooking times studied ranged from 2.25 min to 4 min. Tryptic soy agar plates overlaid with s orbitol MacConkey agar were used for recovery of E. coli 0157:H7. Heat ing of ground beef patties to an internal temperature endpoint of 155 degrees F (68.3 degrees C) resulted in 4-log cycle reductions of the o rganism. The results of this investigation conducted under conditions simulating those that occur in the retail food industry provide a basi s for ensuring safety against E. coli 0157:H7 in ground beef patties.