Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2015
Publication Date: 11/14/2015
Citation: Bowker, B.C., Gamble, G.R., Zhuang, H. 2015. Exudate protein composition and meat tenderness of broiler breast fillets. Poultry Science. 95:133-137.
Interpretive Summary: This study investigated the relationship between meat tenderness attributes and the protein composition of muscle exudates collected from broiler breast fillets deboned at either 2 or 24 h postmortem. Data from this study suggest that the protein composition of muscle exudates collected from broiler breast fillets is not indicative of deboning and muscle shortening induced changes in breast meat tenderness either before or after extended post-deboning aging.
Technical Abstract: The relationship between meat tenderness and the protein composition of muscle exudates collected from broiler breast fillets deboned at different postmortem times was investigated. A total of 85 broilers were processed and breast fillets from each carcass were deboned at either 2 h (early-deboned, EB) or 24 h (control) postmortem. One fillet per carcass was used for day 1 postmortem meat tenderness measurements and the other fillet was stored at 4°C until 6 days postmortem for the collection of exudate prior to tenderness evaluation. Protein content and composition of muscle exudates were determined by a biuret assay and SDS-PAGE. Fillet pH, color, drip loss, and cook loss were also measured. Early-deboned fillets exhibited greater (P < 0.05) Warner-Bratzler shear force (WBSF) than controls at day 1 (7.4 vs. 3.1 kg) and day 6 (4.1 vs. 2.5 kg). Deboning time did not influence pH or color values (L*a*b*). Control fillets exhibited less drip loss after 6 days of storage (P = 0.005) and less cook loss at days 1 and 6 (P < 0.001). Exudate protein concentration was not influenced by deboning time. From the SDS-PAGE profiles of the exudates, the relative abundances of seventeen protein bands were quantified. The band corresponding to 225 kDa was more abundant in controls (P = 0.021). Principal component analysis revealed that when evaluated as a whole, the protein profiles of exudates from control and EB fillets were not distinct from each other. Several significant but weak correlations (|r| < 0.40) were observed between WBSF and exudate protein characteristics (abundance of individual proteins and total protein concentration). Significant correlations were observed between exudate protein composition and measurements of drip loss, pH, and meat color. Although the protein concentrations and SDS-PAGE profiles of muscle exudates varied widely between breast fillets, variations in exudate protein characteristics were not strongly associated with changes in the tenderness of broiler breast meat due to the combined effects of postmortem deboning time and post-deboning aging.