Submitted to: Applied Poultry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 25, 2001
Publication Date: October 1, 2002
Citation: Dickens, J.A., Lyon, C.E., Buhr, R.J. 2002. The effects of electrical stimulation during bleeding on shear values and cook loss of breast fillets from mature chickens deboned at two or twenty-four hours post-evisceration. Applied Poultry Research.
Interpretive Summary: Mature chickens are older and larger birds whose primary existence has been to produce eggs for table or hatching. The mature chickens, when past the efficient egg producing age, have historically been processed for retorted products or rendered by the animal feed industry because the meat is considered too tough for traditional consumption unless aged for at least 8 hours. Pulsed electrical current was passed through mature chickens during the last 60 sec of bleed to see if the expensive breast fillets could be deboned immediately after chilling and still have favorable texture parameters. Mature hens were processed under simulated commercial conditions with or without electrical stimulation (200VAC 1 sec on 1 sec off)and the meat tested for texture (force to shear) and cook loss. Fillets deboned from electrically stimulated birds, immediately after a 2 hr chill, required less force to shear and had less cook loss than non-stimulated birds. Texture and cook loss of fillets deboned after a 24 hr chill were found unaffected by the stimulation. The shear and cook loss values for the 2 h deboned fillets were found to be approximately equal to those of meat deboned after 24 hours.
Electrical stimulation of broilers during bleed-out has been shown to affect the functional properties of breast fillets(Pectoralis), but little work has been reported on mature chickens (broiler breeders). This study evaluated the effects of electrical stimulation during bleed- out on the objective texture and cook loss of breast meat from broiler breeder hens deboned 2 and 24 hours after evisceration. Hens were electrically stunned, 15 V pulsated direct current and killed using commercial equipment. Birds were then allowed to bleed for 90 s or bled for 30 s and electrically stimulated for the remaining 60 s with 200 V alternating current, 1 s on 1 s off. Carcasses were then scalded for 2.5 min at 56 C, defeathered, eviscerated and chilled in an agitated ice bath for 2 h. When carcasses were removed from the chiller the right breast fillet was removed, weighed, vacuum-bagged, and held at 4 C until the next morning. The carcass with the left breast fillet attached was bagged and held at 4 C for an additional 22 h. The next morning the left fillet was removed, weighed, and vacuum-bagged in preparation for cooking. All fillets were cooked at 85 C for 45 min, tempered to room temperature, blotted dry, weighed and two adjacent 1.9 cm wide strips cut and trimmed to a thickness of 1.9 cm. Shear values were determined using a Warner-Bratzler shear devise. Electrical stimulation resulted in 50% lower shear values for the fillets deboned at 2 h (6.8 kg = tender) compared to the non-stimulated fillets (13.8 kg = tough) Cook loss for stimulated fillets(22.6%)was 1.8% less than non-stimulated fillets (24.4%). There was no significant difference in shear values or cook loss for the fillets deboned at 24 h.