Analysis of the effects of hydroxyl radicals on the volatile flavor composition and lipid profile of sheep meat based on HS-SPME–GC–MS and UPLC–MS/MS studies

In order to investigate the relationship between oxidation and sheep lipids and flavor, this study used hydroxyl radical system, headspace solid phase microextraction and gas-phase coupled methods to analyze the effects of different oxidation times (0, 2, 4, 8 and 12 h) on sheep meat lipids and volatile flavor compounds. Results indicate that conjugated diene increased from 2.89 to 7.93 mmol/kg, and thiobarbituric acid reactive substances increased from 0.31 to 1.26 mg MDA/kg within 12 h. Moreover, the levels of volatile compounds such as pentanal, hexanal, benzaldehyde, octanal, nonanal, 1-octen-3-ol, and 2,3-octanedione increased with the increased levels of hexanal, nonanal, and benzaldehyde associated with rancid odor or acidification. Furthermore, 213 differential lipids were identified, primarily enriched in glycerophospholipid metabolism, glycosylphosphatidylinositol-anchor biosynthesis, sphingolipid signaling, and ether lipid metabolism. These lipids and metabolic pathways may play a role in flavor formation during sheep meat oxidation.