Cooking loss in Beef. The effect of cold shortening, searing and rate of heating; time course and histology of changes during cooking

Techniques developed earlier to measure cooking loss in beef sternomandibularis and rectus abdominis muscles under defined conditions, have here been extended to other factors affecting cooking loss. Cold shortening of the muscle has no effect. Searing of the ends before cooking causes a slight increase in loss. In samples cooked for varying times at 80 ºC, cooking loss rises gradually up to 2h, while cooking shortening and shear force reach a maximum much more quickly. Colour changes are described in meat cooked for various times, then cut and exposed to air. Slow cooking gives higher cooking losses than fast, but a lower shear force. Histological studies have shown that in frozen sections maintained in aqueous media the annular shrinkage space is small and does not vary significantly between cooking treatments. The dehydration involved in paraffin sections exaggerate the shrinkage, although these sections show best the fused and apparently intact sarcolemmas. The electron microscope, however, reveals that there are many punctures in the membranes.