Myofibrils of cooked meat are a continuum of gap filaments

When cooked meat is subjected to high degrees of stretch it becomes apparent in high magnification electron micrographs that A-filaments have ceased to exist. The A-band is filled with a coagulum of actomyosin. Fragmentation of this coagulum during stretch reveals an array of fine filaments (identified as gap filaments). This result is obtained irrespective of rigor temperature, state of contraction or degree of cooking. If the meat is first aged, the gap filaments surviving in the I-band are too weak to open up the A-band. The results show that myofibrils in cooked meat are entirely dependent on heat-stable gap filaments for structural continuity and tensile strength. Theories of meat tenderness must be revised accordingly.