Relationship between flavor characteristics and lipid oxidation in air-dried beef at different roasting stages

Lipid oxidation plays a key role in the formation of flavor during hot processing. The purpose of this study was to investigate the lipid oxidation, lipid molecular changes and their effects on flavor of air-dried beef at different roasting stages. The results revealed that the degree of lipid oxidation increased and the unsaturation of fatty acids decreased from 47.30% to 30.77%. A total of 48 volatile compounds were identified by headspace-solid phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). Notably, the types and contents of volatile compounds in S3 group exceeded those in S1 and S2, showing significant differences in the degree of separation among all groups. The aroma differences among the groups were associated with aromatic compounds formed by the oxidation of lipids. Moreover, a total of 59 lipids with significant differences were identified through liquid chromatography-tandem mass spectrometry (LC-MS/MS). These lipids may have major roles in the formation of aromatic compounds, particularly triglyceride, phosphatidylcholine, and lysophosphatidylcholine. This investigation elucidated the mechanisms for the flavor developments of air-dried beef during roasting stages.