The Aerobic Plate Count, Coliform and Escherichia coli Content of Raw Ground Beef at the Retail Level

Abstract

Nine hundred fifty-five samples of raw ground beef obtained from supermarkets throughout the United States were examined for coliforms, Escherichia coli, and Aerobic Plate Count (APC). The results were compared with existent standards for E. coli in raw meat in New York and Oregon. Lack of homogenious distribution of E. coli in fresh ground beef was demonstrated. Observations were made that indicate that a 2 day-two step procedure will detect the same number of E. coli as the more time consuming four step MPN procedure 98% of the time. A comparison of the APC obtained by incubating plates at 20 C and 35 C showed there to be an average 10-fold difference with the 20 C incubation always higher. Questions are raised about the necessity of microbial standards for raw meat and the validity of incorporating E. coli in such standards.