EVALUATION OF LONGISSIMUS-DORSI MUSCLE PH AT 3 HOURS POSTMORTEM AS A PREDICTOR OF BEEF TENDERNESS

The objective of this study was to determine the relationship of beef longissimus dorsi muscle (LM) pH at 3 h post mortem (pH3) and aged LM tenderness. The cattle (n = 444) sampled for this experiment represented various breed types, sex classes, feeding regimes, and post-mortem handling practices. The phenotypic diversity of the cattle used provided a great amount of variation in Warner-Bratzler shear (WBS) force (Coefficient of variation for pH, temperature, and sarcomere length measurements were much smaller than the coefficient of variation for WBS force). None of the parameters measured (LM pH at 3 and 48 h post mortem, temperature at 3 h post mortem and sarcomere length) was strongly related to tenderness. These results do not support the use of pH3 as a criterion for sorting beef carcasses into expected tenderness groups.