Effect of three postmortem electrical stimulation treatments on the quality of early-deboned broiler breast meat

Authors: Zhuang, Hong; Savage, Elizabeth; Lawrence, Kurt

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/15/2010
Publication Date: 8/1/2010
Citation: Zhuang, H., Savage, E.M., Lawrence, K.C. 2010. Effect of three postmortem electrical stimulation treatments on the quality of early-deboned broiler breast meat. Poultry Science. 89:1737-1743.

Interpretive Summary: The present experiment was carried out to evaluate the effects of electrical stimulation (ES) immediately pre-scalding (PS), ES immediately post-defeathering (PD) or PS combined with PD (PSPD) on the quality of early-deboned (2h) broiler breast muscles, pectoralis (p.) major (fillets) and p. minor (tenders). No stimulation, early-deboned (2h) and 24h deboned (24h) fillets were used for the comparison. The broiler carcasses (42 days old) were electrically stimulated with pulsed current at 200 V for 30s (1min total for PSPD), and breast meat was deboned 2h postmortem. Quality indicators evaluated were: CIELAB L*, a* and b* color and pH of the raw fillets; Warner-Bratzler (WB) shear force (cooked meat) and cook yields of the fillets and tenders. There were no differences in raw fillet color and pH between the three ES treatments. Effects of different ES methods on meat WB shear force values and cook yields varied with breast muscles. For the fillets, the average WB shear force values of both the PS and PSPD samples, which were not different from each other, were significantly lower than those of the PD samples. There were no differences in cook yields between the PS and PD, or between the PS and PSPD, although cook yield of the PD samples was significantly higher than the PSPD samples. For the tenders, there were no differences in the average shear force values and cook yields between the three ES treatments. Regardless of ES method and muscle type, early-deboned broiler breast meat from ES carcasses required significantly less force to shear than the 2h control, and more force than 24h control. These results indicate that ES can tenderize early-deboned poultry breast muscles; however, the effectiveness of ES tenderization varies with ES method for the fillets. Single PS is more effective in reducing fillet shear values than single PD, and there is no further reduction in shear values with double PSPD compared to single PS.

Technical Abstract: Electrical stimulation (ES) of animal carcasses during postmortem has been commonly used by beef industry to enhance meat tenderness, and has been recently adapted for commercial use with poultry. Majority of published investigations of ES effects on the tenderness of early-deboned poultry breast meat are based on fillets removed for the carcasses that are stimulated before scalding. However, the most new commercially available ES equipment stimulates poultry carcasses after defeathering, and there is increased interest in applying ES twice before evisceration (double ES) to further accelerate meat tenderization. No comparisons have been made to show if there are any differences in the tenderization of poultry meat between the pre-scalding ES method, post-defeathering ES method and double ES method. Our results show that regardless of ES method and poultry breast muscle type (including both fillets and tenders), early-deboned chicken breast meat from ES carcasses was significantly tenderer than the non-stimulated sample. However, the effects on tenderness of early-deboned fillets varied with the tested ES methods. The double ES before evisceration did not have any advantage in meat tenderization compared with application of single ES before scalding. Application of single ES after defeathering did not tenderize the fillets as effectively as the application of the single ES before scalding or the application of the double ES before evisceration. Our results suggest that single pre-scalding ES should be used for improving tenderness of early-deboned chicken breast meat.