|SAMUEL, DARLENE - Kraft Foods|
Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/26/2014
Publication Date: 5/7/2014
Citation: Eady, M.B., Samuel, D., Bowker, B.C. 2014. Effect of pH and postmortem aging on protein extraction from broiler breast muscle. Poultry Science. 93:1825-1833.
Interpretive Summary: The extractability of muscle proteins influences the water-binding, emulsion capacity, and texture characteristics of further-processed poultry products. This study demonstrated that the extractability of the salt-soluble and water-soluble proteins from fresh broiler breast fillets is dependent upon extraction buffer pH and the postmortem age of the fillets. These factors were found to not only influence the total amount of protein that could be extracted from the muscle but also the composition of the proteins. Understanding these factors is an important step in optimizing protein extraction during the processing of poultry products in order to enhance yield and sensory quality.
Technical Abstract: The objective of this study was to determine the effects of extraction buffer pH and postmortem aging on the extraction of salt-soluble and water-soluble proteins from broiler pectoralis muscle. De-boned broiler breast fillets were collected at 4 h postmortem, packaged, and then stored at 4°C until 1, 5, or 8 days postmortem. After designated aging period, salt-soluble and water-soluble protein extractions were performed with buffers at 7 different pH levels (pH 5.4, 6.4, 6.9, 7.2, 7.5, 8.0, 9.0). Protein concentrations of the extracts were measured and SDS-PAGE analysis was performed. There was not a significant extraction buffer pH by aging treatment interaction for the total protein concentration of either the salt-soluble or water-soluble protein extracts. Salt-soluble protein concentration increased (P<0.0001) as buffer pH increased from pH 5.4 to 6.9 and then remained unchanged from pH 6.9 to 9.0. Water-soluble protein concentration increased (P<0.0001) as buffer pH increased from pH 5.4 to 7.2 and then remained unchanged from pH 7.2 to 9.0. The protein concentrations of salt-soluble extracts was similar at 1 and 8 days postmortem but lower (P<0.0001) at 5 days postmortem. The protein concentration of water-soluble extracts was similar at 1 and 5 days postmortem, but higher (P<0.0001) at 8 days. Both extraction buffer pH and postmortem aging influenced the SDS-PAGE protein profiles of salt-soluble and water-soluble protein extracts from breast muscles. Data demonstrate that postmortem aging and extraction buffer pH influence both the total amount and the composition of the myofibrillar and sarcoplasmic protein fractions that can be extracted from broiler breast fillets.