Postmortem Muscle Metabolism and Meat Tenderness

Left sides of 75 steers were electrically stimulated (ES) and right sides were nonstimulated controls (NES). NES sides had the highest pH, lowest temperature, were slower‐metabolizing (lower R values), and produced steaks that had the least desirable sensory ratings compared to ES sides. Carcass weight, fat thickness, temperature and pH accounted for 31, 32, 34 and 16% of the variation, respectively, in overall tenderness ratings for steaks from NES sides and accounted for 0, 0, 0 and 7% of the variation, respectively, for steaks from ES sides. R values accounted for 28 and 32% of the variation in overall tenderness ratings of steaks derived from NES and ES sides, respectively. Thus, metabolic rate (R value) is a good indicator of postmortem tenderness.