Factors Affecting the Textural Properties of Pork

Abstract

The D sire line had less fat depth and greater percent lean than the C line (P < 0.05). Barrows were fatter than gilts, as evident by more subcutaneous fat, lower percent lean, and more intramuscular fat (P < 0.05). Pork quality measurements were inconsistent over sire line, indicating no advantage to one specific line. Measurements of collagen were lower (P < 0.05) in barrows than in gilts. pH was correlated to most of the traits measured (P < 0.05) and is therefore a useful tool to differentiate products of varying quality. Pork firmness was correlated to a variety of traits (P < 0.05). Firmness had the strongest relationship to pH (r = 0.44; P < 0.05). Stepwise prediction equation included pH, L*, and marbling score, but only explained 33% of the variation in firmness. Overall, pork was very tender at 1 d postmortem with a mean shear value of 2.9 kg; however, there was a lot of variation around the mean. Shear force decreased about 20% from 1 to 14 d postmortem (P < 0.05). Correlations between shear force and the measured quality traits were inconsistent across aging days and the few significant correlations (P < 0.05) showed a weak relationship (r < 0.30). Stepwise regression equations did not contain a common set of traits for all aging days. At 1 d postmortem, the prediction equation could explain 25% of the variation in shear force. At 14, 28, and 42 d postmortem, prediction equations could only explain 26%, 17%, and 11% of the variation, respectively. When segregating loins based on change in shear force between 1 and 14 d postmortem, there was not one unique trait that explained the differences in aging rate (P < 0.05). In the current population of pigs, no single factor or multiple factors were able to adequately or consistently explain differences in firmness or shear force. For the pork industry to move forward with improving quality and consistency, more research needs to address the factors that affect the textural properties of pork.