Comparison of Sarcomere Length to Other Predictors of Beef Tenderness

SUMMARY– Sarcomere length in the longissimus dorsi muscles of 20 bovine animals was compared to other variables in predicting tenderness (Allo‐Kramer shear) in two muscle positions (medial and lateral) and at four cooking temperatures (60, 64, 68 and 72°C). The medial muscle position was less tender, had shorter sarcomeres and had higher correlations between sarcomere length and tenderness than the lateral muscle position. In neither position did sarcomere length account for tenderness variation that was unaccounted for by combinations of other commonly‐used carcass variables indicating that a single measure of sarcomere length at a given position is of little value in predicting tenderness if certain carcass parameters are known. Comparison of sarcomere length with resistance to shear across the cross section of 5 additional longissimus dorsi muscles showed that very small differences in contraction state were associated with marked differences in tenderness in restricted muscle areas. The study emphasizes the importance of post‐rigor contracture to tenderness but indicates that several estimates are necessary to characterize a single muscle.