Changes in texture, cooking losses, and myofibrillar structure of bovine M. semitendinosus during heating

Vacuum-packed slices of bovine semitendinosus (ST) muscle were retorted to internal temperatures of 50, 60, 70, 80, 90, 100, and 121°C. Changes in texture of the meat were evaluated by measurements of Texture Profile Analysis (TPA) parameters. Changes in microstructure were evaluated using a Scanning Electron Microscope (SEM) and measuring fibre diameter and sarcomere length. Cooking losses were also estimated. During heating the TPA parameters changed independently of each other. They reached a maxima at different endpoint temperatures of the meat and then decreased. A decrease in fibre diameter was observed in samples heated to 60 and 121°C. Sarcomere length decreased continuously in the range 50-121°C. Cooking losses increased with increased heating temperature. Relationships between changes in sarcomere length and cooking losses and between springiness and fibre diameter were found.