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 represent ed various breed types, sex classes, feeding regimes, and post-mortem handling practices. The phenotypic diversity of the cattle used provid ed a great amount of variation in Warner-Bratzler shear (WBS) force (C oefficient of variation for pH, temperature, and sarcomere length meas urements were much smaller than the coefficient of variation for WBS f orce). None of the parameters measured (LM pH at 3 and 48 h post morte m, temperature at 3 h post mortem and sarcomere length) was strongly r elated to tenderness. These results do not support the use of pH3 as a criterion for sorting beef carcasses into expected tenderness groups.