Abstract: During the chilled storage of fresh Tan sheep meat, the bacterial proteins and their changes were studied by surface enhanced laser desorption ionization time-of-flight mass spectrometry (SELDI-TOF-MS), and the bacterial metabolites and their changes were detected by gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). Principal component analysis and thermogram analysis were used to investigate the correlation between the changes in bacterial proteins and metabolites. The results showed that the relative contents of some of the bacterial proteins increased with the prolongation of storage period; the relative contents of the metabolites positively correlated with these proteins increased, but the relative contents of those metabolites negatively correlated with these proteins decreased. In contrast, the relative contents of the other bacterial proteins decreased with the prolongation of storage period; the relative contents of the metabolites positively correlated with these proteins decreased, but the relative contents of those metabolites negatively correlated with these proteins increased. Therefore, the changes in microbial proteins on the surface of chilled mutton have an obvious effect on the microbial metabolites during storage. It is speculated that this is because the changes in bacterial protein contents have different impacts the metabolic pathways.

Key words: Tan sheep meat, proteomics, metabolomics, bacterial proteins, metabolites, metabolic pathways