Shocking Technology for Tenderizing Meat

A new patented technology that could turn tough cuts of meat into something akin to filet mignon is nearing the commercial stage. The process, known as hydrodyning, uses underwater shockwaves from a high energy explosive charge to tenderize meat with pressure as high as 25,000 pounds per square inch.

The technology can provide a 50 to 70% improvement in tenderness of less tender meat. In addition, it provides an alternative to fat as a source of tenderness and, based on taste-tests, makes inexpensive cuts of meat taste like higher priced ones.

The inventor of the technique, John Long, came up with the idea of bombing meat 30 years ago while floating in his backyard pool.

"My body has about the same density as the water," he observed, "so if somebody threw a bomb into my pool, the shock waves should go right through me." He began thinking about what those shock waves might do to his muscle -- or to a piece of steak.

Long shelved his idea for 20 years, then in 1988 he teamed up with Stanford Klapper, a marketing specialist, to develop low-cost solar cookers and through that relationship took his novel tenderizing technology back off the shelf.

Long and Klapper approached Morse Solomon, head of meat science studies at the Department of Agriculture's Beltsville Agricultural Research Center near Washington, DC to present their newly patented texturing process. Soon thereafter, Solomon's agency became a research partner of Long and Klapper's firm, Hydrodyne, in San Juan, Puerto Rico.

Not quite two years ago the company took delivery of what it hopes will prove a full scale prototype of the tenderizer. The device can tenderize 600 pounds of meat at once. A 7,000 pound steel tank filled with water is covered with an 8 ft diameter, 5,000 pound steel dome. Large primal cuts of meat, encased in water and pressure resistant wrapping, are lowered into the tank. Then an explosive charge is set off in the water about 2 ft from the meat. The tank's dome holds in water that is forced upwards.

Vacuum-packaged meat being loaded into the basket to be placed inside the Hydrodyning tank.

The system consists of a stainless steel tub 4 ft in diameter fitted inside a shock-absorbing frame. The device must withstand brief impulses of a million pounds of force.

Tenderness is typically measured in kilograms of force needed for a steel blade to slice through a core of cooked meat. As a rule, 4.6 kg is the dividing point. Meat requiring less force to cut is reliably tender, whereas meat needing higher shear forces which can exceed 15 kg ranges from chewy to downright leathery.

With the shock-wave treatment, Solomon says, "I can bring meat that starts with a shear force of 6, 8, or 12 kg down to 3 or 4 every time -- sometimes even lower." For perspective, he notes, well-aged cuts of meat may have a shear force of around 3 kg, and a little below that matches a filet mignon.

Studies indicate that not all meats respond identically to the shock waves, and thus commercial operations may have to separate types or cuts of meat and tailor the explosive power delivered to each. Tenderizing chicken breasts, for example, needs pressures of up to 25,000 pounds per square inch -- almost twice what other meats require.

It has also been discovered that the explosive shock waves can kill germs by rupturing the membranes that encase bacteria. The shock waves can also kill the parasites in pork responsible for trichinosis.

The practical applications of hydrodyne technology has won the company a development grant from the Department of Energy. One case to be made is that 162 million kWh of electricity could be saved annually by treating beef with shock waves and bringing it to market in one week, rather than keeping it refrigerated the few weeks it needs to age. The process would also allow farmers to raise more grass fed livestock which yield leaner, tougher meat thus reducing the demand for energy-intensive feed corn.

For more information contact: Morse Solomon, ARS Meat Science Research Laboratory, Beltsville, MD. Tel: 301-504-8463; Fax: 301-504-8438.