Bacteriological Evaluation of Retail Ground Beef, Frozen Beef Patties, and Cooked Hamburger

Abstract

A total of 108 samples of fresh refrigerated ground beef, 99 samples of frozen hamburger patties, and 107 fried hamburgers, purchased from retail stores and fast-food outlets in Ontario, were analyzed for their bacteriological quality. About 44% of non-frozen ground beef samples had aerobic plate counts exceeding 50 million/g; 50 of 108 samples (46.3%) contained Staphylococcus aureus and 46 of these 50 samples (88%) exceeded 1000 organisms/g; 43 of 108 samples were positive for Escherichia coli with 38 samples (88.4%) exceeding 500 organisms/g. About 19% of frozen hamburger patties had aerobic plate counts in excess of 10 million/g; 93 of 99 samples (93.9%) contained S. aureus with 83 of these samples (89.3%) exceeding 1000 organisms/g; 28 of 99 samples were positive for E. coli with 7 of these samples (25%) exceeding 500 organisms/g. About 96.3% of fried hamburger samples had aerobic plate counts of less than 10,000/g.