COMPARISONS OF THE EFFECT OF ELECTRICAL-STIMULATION METHODS ON POSTMORTEM PH DECLINE IN BEEF MUSCLE

Results of four electrical stimulation (ES) studies were summarized to demonstrate the impact of different ES parameters on pH decline patterns in postmortem M. longissimus thoracis et lumborum. Postmortem pH decline was modeled as a non-linear function of time, and estimates of minimum obtainable pH, pH decline rates, and time to reach pH 6.0 were compared for each study. The decline model for study 4 (AC, 60 Hz, 50 V; 5 min post mortem) had a larger (P < 0.05) estimate for decline rate than that for study 1 (AC, 60 Hz, 400 V, 1 h post mortem) and the control (non-stimulated) data. The model estimate of time to pH 6.0 (0.56 h) for study 4 was the shortest (P < 0.05) for all treatments. Different ES parameters produce different pH decline patterns post mortem and, therefore, may impact product quality and fabrication and chilling protocols adopted in fresh beef processing.