Calcium chloride marination effects on beef steak tenderness and calpain proteolytic activity

A study was conducted in three phases to examine the effect of calcium chloride marination on tenderness. Steaks obtained 5 days postmortem were marinated in a 150 mM calcium chloride solution for 24 h and 48 h in phase 1, and for 48 h in phases 2 and 3. The steaks utilized were obtained from mature cows 8-11 years of age-phase 1; four control and four β-agonist fed steers-phase 2; and three Peidmontese and two Nelore 18-month-old steers-phase 3. Data were analyzed by analysis of variance for a split-plot design. In phase 1, marination failed to improve (P > 0·05) shear force values. However, shear force values were less than 5 kg which was uncommonly low for mature cows. In phase 2, marination improved (P < 0·05) meat tenderness regardless of diet. Yet, the steaks from the β-agonist fed steers remained less tender, even after marination, than the steaks from the control steers. In phase 3, shear force requirements were decreased (P < 0·01) with marination. Also, the activities of m-calpain and calpastatin decreased (P < 0·05) with calcium marination. It appeared that the improvement in tenderness was through the activation of m-calpain.