Title: Relationship of muscle exudate protein composition to broiler breast meat quality Authors
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 26, 2013
Publication Date: May 1, 2013
Citation: Bowker, B.C., Zhuang, H. 2013. Relationship of muscle exudate protein composition to broiler breast meat quality. Poultry Science. 92(5):1385-1392. Interpretive Summary: The ability of fresh poultry muscle to retain its inherent water influences meat quality traits that are important for both consumers and processors. Moisture that accumulates on the surface and in the packaging of fresh poultry products is known as muscle exudate or purge. Relatively little is known about the composition of the purge moisture or how it relates to meat quality attributes. This study investigated the protein content and composition of muscle exudate from broiler breast fillets that varied widely in meat quality. The exudate was found to have a high protein content and the abundance of individual proteins within the exudate were significantly correlated to various measures of meat quality such muscle pH, drip loss, cook yield, and color. These data suggest that muscle exudate might be a potential source for protein markers that can be utilized in the development of rapid, non-invasive techniques for measuring and predicting poultry meat quality.
Technical Abstract: The objective of the current study was to determine the relationship between meat quality and the protein content and composition of muscle exudates from broiler breast fillets differing in fresh meat quality. Deboned broiler breast fillets (n = 72) were obtained from a commercial processing facility and segregated into two groups based on color (light and dark). Muscle pH, color, moisture content, three measures of water-holding capacity (drip loss, water-induced salt uptake, cook loss), protein solubility, and the protein content of muscle exudate were determined in breast fillets. The protein composition of the muscle exudate was evaluation using SDS-PAGE analysis. Light broiler breast fillets had lower muscle pH (4 h and 24 h postmortem) and higher L* and b* values than dark fillets. Light breast fillets exhibited greater drip loss after 2 and 7 days of storage, lower salt-induced water uptake, and higher cook loss than dark fillets. Neither sarcoplasmic nor total solubility differed between light and dark fillets. Protein concentration of muscle exudates was greater in dark fillets and was negatively correlated to drip loss after 2 days of storage (r = -0.50) and salt-induced water uptake (r = 0.42). The electrophoretic protein banding patterns were similar between muscle exudates and sarcoplasmic protein extracts. Gel electrophoresis data from muscle exudates showed that four bands corresponding to 225 kDa, 165 kDa, 90 kDa, and 71 kDa exhibited higher relative abundance in dark breast fillets. The relative abundance of three bands corresponding to 47 kDa, 43 kDa, and 39 kDa was higher in light breast fillets. Various bands within the electrophoretic protein profile of the muscle exudates were significantly correlated to muscle pH and measures of water-holding capacity. Data from this study suggest that protein differences in breast muscle exudate are related to measures of water-holding capacity and that muscle exudate could be a potential source for protein markers for fresh meat quality attributes in broiler fillets.