What is “dark cutting beef?
A It is where beef is dark red to purple in color. To understand “dark cutting beef,” it is necessary to understand how the bright red color of beef occurs. At death, the muscle attempts to maintain all normal activities. To do so, it must have energy in the form of ATP. To get ATP, it breaks down glycogen through postmortem glycolysis. A by-product of postmortem glycolysis is lactic acid. Lactic acid builds up in the muscle over a 16 to 24 hour period post-slaughter. A normal level of lactic acid (pH of 5.6) in the muscle will cause the meat to be bright cherry-red in color when it is exposed to oxygen for a short time period. In “dark cutting beef,” the animal undergoes long-stress before slaughter. This stress may be from transportation, rough handling, changing weather conditions such as cold fronts, or anything that causes the animal to draw on its glycogen reserves before slaughter. At death, there is limited amount of glycogen available to be converted to lactic acid, the muscle
