I. Walls et Vn. Scott, VALIDATION OF PREDICTIVE MATHEMATICAL-MODELS DESCRIBING THE GROWTH OFESCHERICHIA-COLI O157-H7 IN RAW GROUND-BEEF, Journal of food protection, 59(12), 1996, pp. 1331-1335
The growth of Escherichia coli O157:H7 in raw ground beef was investig
ated at 12 degrees C, 20 degrees C, and 35 degrees C at pH 5.7 (unadju
sted) and adjusted to pH 6.3 to 6.4. These growth data were fitted to
the Gompertz equation and the resulting growth kinetics were compared
with predictions from the U.S. Department of Agriculture Patho en Mode
ling Program. Close agreement with the model was obtained at pH 5.7, b
ut at pH 6.4, growth was more rapid than predicted. The U.S. Departmen
t of Agriculture Food Safety and Inspection Service has used this pred
ictive model for developing proposed regulations on time-temperature r
equirements for carcass cooling. As there may be considerable differen
ces in the microenvironment of raw ground beef and a beef carcass, the
validity of using predictive models for estimating growth rates on a
carcass should be determined by performing growth studies on carcass s
urfaces.