Abstract: The study aimed to examine the effects of postmortem ageing on the type and contents of characteristic flavor metabolites and on the metabolic pathways of flavor precursors in the Longissimus dorsi muscle of Tan sheep. Metabolites that differed among the samples aged at 4 ℃ for 0, 4 and 8 day were identified by ultra-high performance liquid chromatography-mass spectrometry. The results showed that among the differential metabolites, flavor precursors such as carbohydrates and organic acids metabolism significantly changed on day 4 and amino acids, nucleic acids and lipids on day 8. The flavor metabolites such as citric acid, beta-citryl-L-glutamic acid, N-acetyl-L-methionine, D-phenylalanine, histidinyl-arginine and eicosapentaenoic acid increased with prolonged ageing. Pentose phosphate metabolism, the tricarboxylic acid cycle, the synthesis of amino acid and purine metabolism were the key metabolic pathways related to the formation of flavor precursors. The study may provide scientific evidence for further study on the role of postmortem ageing in regulating the flavor of Tan sheep mutton.

Key words: Tan sheep meat, ageing, metabolomics, flavor precursors, metabolic pathways