Research from the University of Illinois, Urbana-Champaign, has shown that certain solutions used by meat processors to extend shelf life actually do double duty as antimicrobial agents, killing foodborne pathogens like E. coli 0157:H7. The results of this research were recently published in Meat Science (doi:10.1016/j.meatsci.2006.07.012) and the Journal of Food Science (doi:10.1111/j.1750-3841.2006.00092.x).
E. coli can spread via recycled solutions used to tenderize and enhance flavor in steaks, chops and other cuts of meat, notes Susan Brewer, professor, Department of Food Science & Human Nutrition, University of Illinois. The problem motivated Brewer and her graduate students to study the process used to inject meat with enhancement solutions. “We wanted to find a point in the process at which we could exert some kind of control to keep foodborne pathogens from becoming a problem,” she said.
Brewer said that needle injection has been widely used for decades to tenderize meats, and more recently the fresh-meat industry has adopted the use of enhancement solutions, a practice that poultry and ham processors have used for years with very few problems. “A certain amount of fat makes meat juicy and tasty, but in recent years consumers have been demanding leaner and leaner cuts of meat. Processors are now using the needles that tenderize steaks and chops to inject solutions that make the meat taste better and last longer,” she said.
“With needle injection, organisms that exist on the outside of a piece of meat can get poked down into the meat where they’re less likely to be killed if consumers like their meat on the rare side,” said Brewer. Also, as the needles inject one piece of meat after another, they can spread contamination from one piece of meat to another, and recycled enhancement solution can further complicate the spread of pathogens.
In the first study, the researchers contaminated the surface of meat with E. coli K12, an indicator organism for its more dangerous relative, to observe the pathogen’s progress as meat went through the system. “We inoculated meat at various microbial loads, with some seriously nasty surface contamination on some pieces of meat,” said Brewer. In the second study, they added E. coli K12 into the enhancement solution itself, experimenting with different components and combinations.
They found that some solutions used to extend the shelf life of meat also were effective at killing bacteria. “In certain solutions containing sodium lactate or sodium diacetate, bacteria cells couldn’t grow and were substantially reduced. These shelf-life enhancers definitely work, and it really doesn’t make any difference whether the steak itself or the solution is contaminated,” Brewer said.
To read the complete University of Illinois press release, see http://www.aces.uiuc.edu/news/stories/news3795.html.