EFFECT OF MUSCLE OPPOSITION DURING RIGOR ON DEVELOPMENT OF BROILER BREAST MEAT TENDERNESS

Two experiments were conducted to determine the effect of mutual oppos ition of breast muscles during rigor development on ultimate tendernes s of the cooked meat. In each experiment, 32 broilers were conventiona lly processed. Immediately after evisceration, the supracoracoideus te ndon was cut at the humeral insertion on one wing (treatment) and the opposite wing was sham-operated with the tendon exposed but not cut (c ontrol). The tendon of insertion for the Pectoralis minor muscle was c ut to prevent the opposition of breast muscles during rigor, while avo iding confounding effects caused by making cuts on the muscles,as woul d occur during typical deboning. Cutting the tendon significantly (P < 0.05) increased Warner-Bratzler shear values after cooking for both th e Pectoralis major and P. minor. Deboning at 2 h postmortem resulted i n shear values for the P. major of 7.22 kg for controls and 9.08 kg fo r treated carcasses; P. minor shear values were 2.98 kg for controls a nd 4.04 kg for treated carcasses. Deboning at 24 h post-mortem produce d P. major shear values of 4.68 kg for controls and 5.68 kg for treate d carcasses. On whole carcasses, breast muscle opposition during rigor contributes to the tenderness of the cooked meat.