MICROBIOLOGICAL EVALUATION OF PRECOOKED BEEF PATTIES CONTAINING SOY PROTEIN

Beef patties of 7 formulations, 6 containing soy protein concentrate and/or textured vegetable protein, were frozen raw or immediately after they were precooked to an internal temperature of 60-65.degree. C. Addition of soy protein had no effect of any practical significance on the microflora of the raw or precooked patties. Precooked patties of all formulations contained significantly (P < 0.05) lower aerobic plate counts (20.degree. C) and MPN''s [most probable numbers] of coliforms, fecal coliforms, Escherichia coli and Staphylococcus aureus than the raw patties. E. coli and S. aureus could not be detected in 90% of the precooked patties. Clostridium perfringens was not detected in any of the precooked patties and was found in very low numbers in only 7% of the raw patties. Salmonellae were not detected in the raw or precooked patties.