Salmonella was more resistant to heat treatment of whole cuts of beef than in ground beef products, according to a study in the Journal of Food Science, published by the Institute of Food Technologists.
Although the interior of whole cuts of beef products has long been assumed to be sterile, contamination and survival of pathogens have been reported. Studies have found that Salmonella does migrate and survive inside the muscle. Researchers at Michigan State University evaluated the relationship between heat resistance of Salmonella and degree of grinding (whole muscle, coarsely ground, finely ground, and beef puree). All products came from the same original lot of beef and received the same thermal treatment.
Researchers suspected that the water status in meat may impact the effectiveness of Salmonella inactivation and that bacteria may be suspended in the liquid component of the food.
Salmonella exhibited greater heat resistance in whole muscle beef. The physical structure of beef products influenced Salmonella heat resistance. However, no significant difference in thermal resistance was seen between coarsely ground, finely ground and pureed samples, according to lead researcher Bradley Marks.