A comparative study of Sus scrofa M. longissimus dorsi with different changes in quality

The comparative study of Sus scrofa muscle tissue with different defects of quality was carried out. Such analysis methods as determination of water-binding capacity (WBC) and pH values, microstructural studies, proteome methods, mass spectrometric methods, high performance liquid chromatography (HPLC) and determine the concentration of cathepsin D, calpain 3 and myoglobin were applied in current study. DFD meat was characterized by high pH (6.2) and WBC (93.18%), while PSE - low pH (5.5) and WBC (79.19%). pH and WBC values in NOR pork was medium and averaged 5.9 and 92.05%, respectively. Microstructural studies revealed that fiber in exudative pork was the least and averaged 39.7 µm, normal pork was characterized by diameter of muscle of 45.5 µm, while DFD pork ‑ 48.3 µm. Protein composition of Sus scrofa muscle tissues were also investigated by one-dimensional and two-dimensional electrophoresis. 6 protein fractions were identified by mass spectrometry and confirmed as potential biomarkers of pork quality defects in meat and processes meat product. It also has been shown that PSE pork contains 8 characteristic peptides, NOR - 14, DFD - 18. Cathepsin D, calpain 3 and myoglobin content were measured in pork of different categories. The highest content of cathepsin D, calpain 3 and myoglobin was noticed in PSE pork and averaged 82.16 ±3.30 ng.mL-1; 1.280 ±0.082 ng.mL-1; 3.973 ±0.506 ng.mL-1, respectively. Since the study was carried out on samples of meat 24 hours after slaughter, this work had the prospect to further study of meat with different defects of quality during long-term autolysis