Association of Some Porcine Muscle Characteristics with Postmortem Temperature and Plasma 17-Hydroxycorticosteroid Levels

Abstract

The association of postmortem muscle temperature with chemical and physical properties of the M. longissimus and plasma 17-hydroxycorticosteroids from pigs receiving a minimum of preslaughter stress was studied. A nonsignificant narrow range of plasma 17-OHCS between the Duroc, Poland China, Hampshire and Yorkshire strains was found. Antemortem stress under the reported slaughter conditions appeared to have little influence on plasma 17-OHCS levels from the four strains. But differences between strains in the rate of pH decline and ultimate physical properties of the M. longissimus were evident in sides held at 2° C. The Poland China strain exhibited muscles with fastest rate of glycolysis and lowest subjective color and firmness score. Retaining carcasses at 40° C. for 4 hr. postmortem accelerated the rate of pH decline and decreased water-binding capacity. Color and gross morphological changes appeared related more to changes in pH during early postmortem periods than to the ultimate pH. At the end of the 24 hr. chill period, chilled sides were darker and less exudative than those held at the higher temperature. However, muscles held at 40° C. were also adjudged slightly pale, but normal in firmness and degree of exudation. Sarcoplasmic and myofibrillar protein extractability was greatly reduced in unchilled muscles. Copyright © 1969. American Society of Animal Science . Copyright 1969 by American Society of Animal Science