A survey of pH values at the surface of beef and lamb carcasses, stored in a chiller

Abstract The surface pH values of lamb and beef carcasses stored at 5 ºC have been measured over a 5‐day period. In both types of animal, muscle surfaces were at or near their minimum pH at 3 days, when the overall mean was pH 6.4. In the subsequent 2 days some sites showed no change in pH, while at others a small drop or a rise occurred. Rises in pH tended to be more common and greater on the beef. In lamb, intact muscle surfaces varied only from pH 6.3 to 6.6 at 3 days, while beef muscles varied widely, from pH 5.8 to 7.1. Muscle surfaces cut during dressing fell much more rapidly in pH, particularly in beef. Fatty sites fell from near pH 8.0 to near pH 7.0. The pH of beef surfaces chilled to ‐3 ºC fell more rapidly to lower final values than those at 5 ºC. At 5 ºC there was little multiplication of bacteria on fat surfaces, whereas on muscle they grew moderately, irrespective of pH.