The Science Behind Making Steak More Tender

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.