pale, soft, and exudative meat

Pale, soft, and exudative (PSE) meat is a quality issue that arises from a rapid decrease in pH while the muscle temperature remains high after an animal's death. This combination negatively impacts muscle proteins, reducing their water-holding capacity, which causes the meat to drip and appear soft and mushy. The proteins also reflect light differently, making the meat look pale. PSE meat is particularly common in the pork industry and can be linked to stress experienced by the animals before slaughter, and in some cases, it may have a genetic component.1

Normally, after an animal is slaughtered and bled, muscle cells no longer receive oxygen. This leads to anaerobic glycolysis, where glycogen is converted to lactic acid, causing the muscle's pH to drop from about 7.2 to around 5.5.2