Alternative pre-rigor foreshank positioning can improve beef shoulder muscle tenderness

Thirty beef carcasses were harvested and the foreshank of each side was independently positioned (cranial, natural, parallel, or caudal) 1h post-mortem to determine the effect of foreshank angle at rigor mortis on the sarcomere length and tenderness of six beef shoulder muscles. The infraspinatus (IS), pectoralis profundus (PP), serratus ventralis (SV), supraspinatus (SS), teres major (TM) and triceps brachii (TB) were excised 48 h post-mortem for Warner-Bratzler shear force (WBSF) and sarcomere length evaluations. All muscles except the SS had altered (P<0.05) sarcomere lengths between positions; the cranial position resulted in the longest sarcomeres for the SV and TB muscles whilst the natural position had longer sarcomeres for the PP and TM muscles. The SV from the cranial position had lower (P<0.05) shear than the caudal position and TB from the natural position had lower (P<0.05) shear than the parallel or caudal positions. Sarcomere length was moderately correlated (r=-0.63; P<0.01) to shear force.