Hydrodynamic Pressure Process May Make Meat Safer

WASHINGTON, Dec. 7--A process to make ground meat more tender may also make it safer to eat, Agricultural Research Service Administrator Floyd Horn announced today.

In the process, called the Hydrodynamic Pressure Process (HDP), ARS scientists place meat in a container of water, then detonate a small amount of explosives that create a shock wave in the water. The shock wave tenderizes meat by severing the stringy striations that can make meat tough.

“The scientists initially used this process to tenderize meats, but in new studies have found that it also reduces foodborne pathogens in meat,” Horn said. “A treatment such as HDP would certainly be a boost for food safety in this country and good news for consumers.”

Escherichia coli and other pathogens can live and grow in ground meat, causing illness if the meat is improperly handled. But concerns about meat being contaminated with dangerous pathogens may be relieved by HDP.

Scientists conducted additional studies with a technologically superior mechanism to refine the process. Surprisingly, the advanced mechanism--a metal, thick-walled tank (called the mini-tank) imbedded in the ground--did not tenderize meat as well. But the scientists found an added benefit: There seemed to be fewer bacteria on the meat than before.

Scientists had already proven that HDP penetrated throughout whole cuts of meat, making them more tender. At that point, they wanted to see if bacteria were reduced throughout ground meats as well.

Studies were conducted to determine the effect of HDP on naturally occurring spoilage or shelf-life bacteria found in ground beef. The studies showed a “three-log” reduction in shelf-life bacteria. This would be similar to reducing 30,000 colony-forming units (cfu’s) to 30 cfu’s. A five-log reduction is the “gold standard” for bacterial reduction, so studies are ongoing to further reduce bacterial levels.

Additional studies were performed to determine the effect HDP has on E. coli 0157:H7 in fresh ground beef, again with encouraging results. Ground beef that had been seeded with E.coli 0157:H7 had no detectable levels of the dangerous organism after HDP treatment.

HDP doesn’t kill all bacteria, “but this may be a good thing,” said ARS meat science researcher Morse Solomon. “Lactobacilli, which are good bacteria, remain.” HDP seems to inactivate most meat pathogens, such as E. coli.

Further studies are necessary to determine if HDP can be put to practical use in a commercial setting. “HDP can penetrate through a product, reducing or eliminating pathogens throughout ground meat,” said Solomon. “The ability to treat packaged meats may substantially reduce health risks in the future.”

ARS is the U.S. Department of Agriculture’s chief scientific research agency.

Scientific contact: Morse Solomon, ARS Food Technology and Safety, Beltsville, Md, phone (301) 504-8463, fax (301) 504-8438 msolomon@lpsi.barc.usda.gov.