Elucidating key lipids driving aroma differences and potential formation pathways in marbled beef with interindividual lipid variations

Intramuscular fat (IMF) content and lipid classes affect beef aroma, but their interindividual variations and impacts on aroma formation remain unclear. Here, we investigated the impact of divergent IMF/neutral lipid–phospholipid profiles on lipidomes and odorant profiles via absolute quantitative lipidomics and volatilomics. Lipidomic analysis revealed significant alterations in free fatty acids (FFAs), phosphatidylcholines (PCs), phosphatidylethanolamines (PEs), and triglycerides (TGs), collectively driving interindividual variations at both class and molecular levels. Moreover, unsaturated fatty acyl compositions of these lipids showed group-specific differences, with TGs, PCs, and FFAs dominated by C18:1 and C18:2 chains, while PEs were enriched in C18:2 and C20:4. Thirteen odor-active compounds were identified as critical to beef aroma, with hexanal, pentanal, 1-octen-3-ol, 1-octen-3-one, nonanal showing 74%, 27%, 54%, 38%, 34% inter-group differences in content, respectively ( p  < 0.05). Specific fatty acyl-containing TGs, PCs, and PEs (C18:1, C18:2, and C18:1e) were critical for odorant generation and retention.