Hydrodynamic Pressure May Make Meat Safer.

A process designed to make ground meat more tender may also make it safer to eat, U.S. Department of Agriculture (USDA) Agricultural Research Service (ARS) administrator Floyd Horn announced in December 2000.

The process, called the "hydrodynamic pressure process" (HDP) involves placing meat in a container of water, then detonating a small amount of explosives to create a shock wave in the water. The shock waves sever the stringy striations that can make meat tough. New studies have found that the process also reduces food-borne pathogens.

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 3-log reduction in shelf-life bacteria. A 5-log reduction is the gold standard for bacterial reduction, so scientists are continuing to look for ways of further reducing bacteria levels.

Additional studies were performed to determine the effect of HDP on E. coli 0157:H7, again with encouraging results. Ground beef that had been seeded with E. coli 0157:H7 had no detectable levels of the 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, however.

Further studies are needed 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."