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Food technologists Tommy Wheeler (left) and Stephen Shackleford (middle) prepare muscle for calpain extraction as physiologist Mohammad Koohmaraie separates calpain and calpastatin from a meat extract. Click the image for more information about it.

The Science Behind Making Steak More Tender

By David Elstein
February 3, 2005

Consistently tender steaks may be more readily available at restaurants and supermarkets in the future, thanks to technology developed by Agricultural Research Service (ARS) scientists in Nebraska and used by beef processors.

At the ARS Roman L. Hruska U.S. Meat Animal Research Center in Clay Center, Neb., animal physiologist Mohammad Koohmaraie is leading a group of researchers in determining how to make steaks more tender. Some of their discoveries are already being used by industry.

The scientists noticed meat is tender after slaughter, then toughens before starting to become tender again. Accordingly, the scientists believe steaks shouldn't be sold before they've aged for 14 days, to make sure the meat has undergone maximum tenderization. A majority of beef processors are already following this procedure.

They also discovered the enzyme µ-calpaina and the variation of the protein called calpastatin, both of which have a major impact on meat tenderness. Calpastatin determines how much calpain is active and how tender the steak will be. Since calpain requires calcium for activity, the team has developed a process for injecting calcium into meat in order to make it tender.

The scientists are also studying cattle genetics. Under the leadership of chemist Tim Smith, they are comparing the sequences of genes that produce calpain in both tender and tough cattle. They have released a DNA test that accurately identifies which cattle will likely provide tender steaks, so producers can use those animals for breeding.

Read more about the research in the February 2005 issue of Agricultural Research magazine.

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