The relative precision of different methods of measuring pH in carcass muscles

Comparisons between a sample method and a direct probe method for measuring the ultimate pH in muscles of sheep indicated that the two methods have the same relative precision. However, the precision of the probe method was considerably less than the sample method in measuring the pre-rigor pH decline. A greater degree of within muscle variation of ultimate pH values was found in the M. supraspinatus as compared to the M. biceps femoris and the M. longissimus dorsi. Although differences were observed in pH values between different sites within the M. longissimus dorsi of both sheep and cattle, it was shown that such differences appear to occur at random and therefore the site of sampling of this muscle is of little importance in relation to the precision of the test. Statistical evaluation of data from these studies also indicated that there is little advantage in taking multiple samples when measuring the ultimate pH of this muscle.