Post-mortem Lability of Skeletal Muscle Proteins

Abstract

AS a result of the post-mortem conversion of glycogen to lactic acid, the pH of skeletal muscle falls from its in vivo value of about 7.3 to about 5.5, the actual level attained depending on several factors, such as the physiological state of the animal before death, the type of muscle and the temperature during glycolysis^1,2. It has recently been shown in pig muscle that, where the rate of pH fall is fast and a relatively low pH is therefore attained while the temperature is still high, there may be considerable denaturation and precipitation of sarcoplasmic proteins³. It is also well known in enzyme preparatory procedures that lowering of the pH of extracts from animal tissues precipitates particulate material and nucleo-protein⁴.