Quality variation and flavor profiling of pork: Kinetic modeling and marker identification during storage at varied temperatures

Monitoring the quality changes of pork during storage is essential for ensuring its preservation. The changes in quality and volatile flavor compounds (VFCs) in pork stored at different temperatures were investigated in this study. Pork samples were stored at 25 °C, 4 °C, or −20 °C. On each test day, four physicochemical indices were measured, including pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), and sensory score. The results indicated that the changes could be accurately modeled using a zero-order kinetic model combined with the Arrhenius equation. Additionally, the VFCs in pork were analyzed using headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS). Significant differences in flavor compounds were observed across different storage temperatures. Cluster analysis classified the pork samples into two groups: fresh and sub-fresh pork, and spoiled pork. The orthogonal partial least squares discriminant analysis (OPLS-DA) model was employed to identify potential freshness markers. Compounds meeting the criteria of the T-test ( p < 0.05) and having a VIP value greater than 1 were considered potential differential markers. Ultimately, nine potential difference markers were identified: hexanal, 2-pentylfuran, heptanal, acetoin, dimethyl trisulfide, trisulfide, benzaldehyde, pentanal, nonanal, and dimethyl disulfide. This study offers valuable insights for pork storage and quality control. • The quality changes in pork stored at 25 °C, 4 °C, or −20 °C were measured. • Volatile flavor compounds were simultaneously measured by HS-SPME/GC-MS. • Quality was modeled using zero-order kinetic model combined with Arrhenius equation. • Pork samples were classified into two groups by cluster analysis. • The OPLS-DA model was used to identify potential freshness markers.