Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/28/2015
Publication Date: 7/27/2015
Citation: Bowker, B.C., Zhuang, H. 2015. Protein degradation and post-deboning tenderization in broiler breast meat with different degrees of muscle shortening. Poultry Science Association Meeting Abstract. volume 94(E-Suppl. 1), page 169.
Interpretive Summary: none
Technical Abstract: Deboning broiler breast fillets prior to rigor mortis negatively influences tenderness due to sarcomere shortening. The effects of sarcomere shortening on muscle protein degradation and breast meat tenderization during post-deboning aging are not well understood. The objective of this study was to measure changes in tenderness and muscle protein degradation with post-deboning aging in broiler breast meat with differing sarcomere lengths. Fifty-six broilers were slaughtered and breast fillets were deboned at either 2 h (early-deboned, EB) or 24 h (control) postmortem. Samples were stored at 4°C and fillet tenderness (Warner-Bratzler shear force, WBSF) was assessed on days 1 and 6 postmortem. Sarcomere length was measured and protein degradation was assessed using myofibrillar fragmentation index (MFI), SDS-PAGE, and western blot analysis of myofibrillar proteins. Average sarcomere lengths were shorter (P<0.0001) in EB fillets compared to controls. EB fillets exhibited greater (P<0.05) WBSF than controls at days 1 and 6 postmortem. Aging decreased (P<0.0001) WBSF in EB fillets, but the WBSF decrease with aging in controls was not statistically significant. Muscle protein degradation occurred in control and EB fillets between days 1 and 6 postmortem. Aging increased (P<0.0001) MFI in all fillets, but the increase was greater in controls. SDS-PAGE analysis revealed that the relative abundance of 11 myofibrillar protein bands changed with postmortem aging in all fillets. With aging, decreases (P<0.0001) in intact desmin and increases (P<0.05) in desmin breakdown products were observed in both EB and control fillets using western blotting. Aging related differences in SDS-PAGE and western blot profiles were similar between control and EB fillets. These results demonstrate that significant changes in muscle protein degradation and tenderness occur in broiler breast fillets between days 1 and 6 postmortem, but suggest that differences in muscle shortening due to deboning time do not substantially influence the extent of muscle protein degradation during post-deboning aging.