Exudate protein composition and Warner-Bratzler shear force in broiler breast fillets

Authors: Bowker, Brian; Zhuang, Hong

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/19/2013
Publication Date: 7/22/2013
Citation: Bowker, B.C., Zhuang, H. 2013. Exudate protein composition and Warner-Bratzler shear force in broiler breast fillets [abstract]. Poultry Science Association Meeting Abstract. 92:50.

Interpretive Summary:

Technical Abstract: Muscle exudate is often associated with pale color and poor water-holding capacity in broiler breast meat. The relationship between exudate protein composition and breast meat tenderness is unknown. The objective of this study was to determine the relationship between exudate protein composition and Warner-Bratzler shear force (WBS) in broiler breast fillets deboned at 2 and 24 h postmortem. Broilers (n=85) were slaughtered and breast fillets were deboned at either 2 or 24 h postmortem. One fillet per carcass was used for meat quality measurements at 24 h postmortem and the other fillet was stored until 6 days postmortem for the collection of muscle exudate and subsequent meat quality measurements. Protein content and composition of muscle exudates were determined by the biuret assay and SDS-PAGE. Fillets deboned at 2 h exhibited higher (p<0.0001) WBS than fillets deboned at 24 h at both 1 day (7.43 vs. 3.11 kgf) and 6 days (4.07 vs. 2.50 kgf) postmortem. Deboning time did not influence meat color or ultimate pH, however, fillets deboned at 24 h had lower (p<0.01) drip loss and lower (p<0.001) cook loss at 1 and 6 days postmortem. Protein concentrations of the exudates were not influenced by deboning times. The relative abundance of fifteen protein bands (24-220 kDa) was quantified from the SDS-PAGE profiles of muscle exudates and found to be similar between fillets deboned at 2 and 24 h. In fillets deboned at 24 h, three protein bands were correlated to WBS at day 1, two protein bands were correlated to WBS at day 6, and five protein bands were correlated to the WBS decrease from day 1 to 6 postmortem. In fillets deboned at 2 h, two protein bands were correlated to WBS at day 1 and one protein band was correlated to WBS at day 6. Overall, data indicated that exudate protein composition was more closely related to tenderness differences due to postmortem aging rather than tenderness differences due to deboning time. These results suggest that muscle exudates may be a potential source of protein markers for breast fillet tenderness differences related to postmortem proteolysis.