BIOPHYSICAL BASIS OF PALE, SOFT, EXUDATIVE (PSE) PORK AND POULTRY MUSCLE - A REVIEW

Problems with meat quality are usually caused by aberrations in the bi ochemistry and morphology of individual muscles, as well as by postmor tem events. Poultry, like pigs, have been subjected to intense genetic selection for rapid lean muscle growth. The selection traits are most often associated with economic importance rather than biophysical sig nificance which often results in stress syndromes (e.g. porcine stress syndrome) and pale, soft, exudative (PSE) muscle conditions. The occu rrence of PSE muscle and subsequent alterations in meat quality has be en shown to be related to increases in muscle size, stressful preslaug hter handling conditions, and rate of onset of rigor mortis. Morpholog ical studies have revealed significant increases in fiber size, in add ition to structural irregularities in PSE muscle. These structural irr egularities include decreased capillary density, hypercontracted (gian t) fibers, and myoplasmic calcium loading. The common theme between po ultry and swine in the development of PSE muscle is predominately in a naerobic fast-twitch muscles with low energy lactate metabolism yet ac celerated onset of rigor mortis.