CHANGES IN TENDERNESS OF BEEF LONGISSIMUS DORSI AS RELATED TO MUSCLE COLOR AND pH

Longissimus dorsi shear values for carcasses of 168 steers, 147 heifers and 259 bulls, all slaughtered in the age range of 12–16 months, were correlated with postmortem pH values and postmortem change in pH. Neither the individual pH values nor degree of postmortem pH change were useful predictors of shear value for steer and heifer carcass (r 2 values less than 0.07). For bull carcasses, pH of the longissimus dorsi taken 24 hr postmortem was significantly correlated with shear value, (r =−0.7) and with meat color (r =+0.7). Sexes differed markedly in the range of 24 hr pH of the longissimus dorsi with none of the steers, 8% of the heifers and 49% of the bulls having values greater than 6.0.