Rigor Mortis and Glycolysis

ATP is required for actin and myosin to separate. When ATP is depleted, stable actomyosin bonds form and the muscle becomes stiff and less extensible.

The rate and extent of pH decline depend on glycogen, stress, species, muscle and temperature. Abnormally rapid or limited decline contributes to PSE- or DFD-like meat quality.

Very rapid chilling before rigor can cause cold shortening in susceptible muscles, while high temperature with rapid acidification can denature proteins. Time, temperature and pH therefore need to be considered together.

Pre-rigor meat may have high water-holding and extraction potential, but it must be processed and chilled rapidly. Post-rigor raw material has different structure and requires formulation based on its actual functionality.

Rigor mortis is a normal stage in the conversion of muscle to meat. It should be used to explain texture, pH and water retention, not presented as a pathogen-kill step or universal processing clock.