Research noteProteomic analysis of meat exudates to discriminate fresh and freeze-thawed porcine longissimus thoracis muscle

•Proteomics was employed to discriminate between fresh and freeze-thawed (FT) pork.•In total, 450 proteins were identified in meat exudates by 2-DE and MS analysis.•Twenty-two proteins were selected as discrimination markers for fresh or FT pork.

The present study adopted a proteomics approach to discriminate between the expression of different proteins in meat exudates from fresh and freeze-thawed (FT) pork. The porcine longissimus thoracis muscles were stored at 1.0 ± 0.5 °C for 60 h, and the remainder was exposed to freeze-thawing at −20.0 ± 0.5 °C for 48 h and at 1.0 ± 0.5 °C for 12 h. The released meat exudates were collected, and the amount of exudate and the protein content and expression were analyzed. Two-dimensional gel electrophoresis and mass spectrometry (2DE/MS) identified 450 protein spots from meat exudates. The expressions of 15 and 9 proteins were significantly (p < 0.05) higher in the fresh pork and in FT pork, respectively. 22 proteins could be selected as markers to discriminate between fresh and FT pork.