Effect of ultimate pH on the quality characteristics of pork

A study was conducted to characterize the relationship between Longissimus thoracis ultimate pH (LTpH) and pork quality. Animals (n=47) were selected based on LTpH measured at 24 h postmortem. Data were analyzed using regression procedures with ultimate pH as the independent variable, and relationships were determined to be linear (L), quadratic (Q) or cubic (C). Ultimate pH explained 79% (C) of the variation in subjective color, which increased as pH increased. Drip loss, purge loss and L* value decreased as LTpH increased (R ² = 0.57C, 0.77 Q and 0.68 Q, respectively). Shear force decreased and sensory juiciness increased as LTpH increased (R² = 0.26Q and 0.46C, respectively). However, off flavor intensity increased as LTpH fell below pH 5.2 or exceeded 6.1 (R²=0.52C). Increasing LTpH, up to a point, will improve fresh pork quality and processed meat properties, whereas, above approximately 6.1, off-flavor may increase.