Comparative Proteome Analysis of Porcine Longissimus dorsi on the Basis of pH24 of Post-mortem Muscle

To identify proteins contributing to meat quality, a comparative shotgun proteomic profiling of Berkshire longissimus dorsi muscles was conducted in high pH group (HpHG) and low pH group (LpHG) based on 24 hour post-mortem pH. Triplicate liquid chromatography–tandem mass spectrometry analysis identified a total of 208 and 204 proteins in the HpHG and LpHG, respectively. A total of 128 proteins were classified on the basis of molecular function, cellular components, and biological process by gene ontology analysis, of which 13 and 21 proteins were exclusively found in the HpHG and LpHG, respectively. A total of 15 proteins, of which 6 proteins belonged to the LpHG and 2 to the HpHG, were assigned to the Sus scrofa genomic database. The dominant expressions of Igc, Prep, Ldhb, and Aco2 were identified in the LpHG by shotgun proteomic analysis, and confirmed by reverse transcriptase–mediated polymerase chain reaction analysis. These protein markers are suitable for determining meat quality.