Thermal effects on chicken and salmon muscles: Tenderness, cook loss, area shrinkage, collagen solubility and microstructure

The objective of this study was to gain insight into the mechanisms underlying heating-induced tenderness in muscle food products by comparing tenderness changes in chicken breast (Pectoralis major) and salmon (Oncorhynchus gorbuscha) during high-temperature treatment. Relationships among changes in chicken breast and pink salmon muscle were investigated for tenderness, cook loss, area shrinkage, collagen solubility and microstructure. Small white muscle samples (D 30mm H 6mm) cut from pink salmon fillets and chicken breast were sealed in small aluminum containers (internal dimension: D 35mm H 6mm) and heated in an oil bath at 121.1 1C for different time intervals up to 2 h to simulate various thermal process durations. The changes in salmon tenderness had 4 phases (rapid toughening, rapid tenderizing, slow toughening and slow tenderizing), while that of the chicken breast only had 2 phases (rapid tenderizing and slow tenderizing). Twenty minutes was found to be a critical heating time in which 485% collagen was solubilized and shear force reached a minimum. Cook loss and area shrinkage were significantly (Po0.05) correlated with shear force change for both the salmon and chicken, while collagen solubility was only significant for the chicken. r 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.