ULTIMATE pH EXPLAINS VARIATION IN PORK QUALITY TRAITS

ABSTRACT

The objective of this study was to determine the relationship between pH and fresh pork quality. Pigs (n = 988) were harvested at one plant on 6 days over a 2-month period. Loin pH was recorded at 45 min, and 3 and 24 h postmortem. Loins (n = 840) were classified based on ultimate pH into four categories: low (≤5.44), low/normal (5.45–5.74), high/normal (5.75–6.04) and high (≥6.05). A majority of loins (53.3%) were classified as low/normal, while only 1.3% were classified as low. It was confirmed that 24 h pH was the best predictor of key meat quality traits because 45 min and 3 h pH accounted for less than 5% of the total variation in quality traits. The pH at 24 h postmortem is the best predictor of quality of the three time points tested in this population, because it accounted for over 10% of the variation in several quality attributes.

PRACTICAL APPLICATIONS

Ultimate pH is becoming more widely used in industry applications to segregate carcasses prior to fabrication. The pH has been linked to several important attributes of pork quality, including water-holding capacity, tenderness and color. While it has been suggested that the pH measured at earlier time points postmortem can be used to predict pork quality, the results of this study suggest that the pH at 24 h postmortem is the best predictor of these characteristics. The addition of 45 min or 3 h pH is of little predictive value for meat quality characteristics in this population. While 24 h pH accounts for some variability in pork quality attributes, more work is still needed to determine factors impacting the quality of pork.