Postmortem Delay Time and Heating Rate Affect Tenderness and Ultrastructure of Prerigor Cooked Bovine Muscle

The response of prerigor bovine muscle to different heating conditions was determined. Samples were fast‐heated at six postmortem times or at five heating rates at four early postmortem times. All samples were heated to 70°C internally. Prerigor muscle cooked at progressively shorter postmortem times and faster heating rates had correspondingly lower shear values. In prerigor fast‐heated samples, phase contrast microscopy revealed transverse bright stripes along the myofiber while scanning electron microscopy showed transverse surface wrinkles, bulges, interior contraction bands, and stretched areas. Postmortem time and heating should be controlled to improve beef tenderness.