Measurements of pH(60) in pork using ISFET/REFET and glass electrode methods

pH values of 180 pork longissimus dorsi muscles were obtained using different measurement methods. A glass combined penetration electrode and an ISFET/REFET pH sensor system were used directly in the muscle, whereas in the homogenate, pH was assessed with a glass combined electrode. The results showed that no statistically significant differences were obtained between the methods in all tested samples. However, samples where pH(60) stood below 5·9, produced a better agreement between methods. Comparing the values obtained from the two direct puncture methods in the first group of samples (pH<5·9) the I/R probe appeared to agree with those obtained from the homogenates. While working, the ISFET/REFET system proved to be a good device to detect carcasses with fast post mortem pH decline. Nevertheless, the excessive time required display stabilisation prohibits its use for continuous measurements on high speed slaughter-lines.