Multi-omics Analysis of Lipids and Aroma Compounds in Beef under Grain-fed and Grass-fed Production Methods

Different production methods for grain-fed and grass-fed cattle affect beef quality and flavor, yet systematic studies on aroma profile differences and the reasons underlying these variations remain limited. This study employed multi-omics analysis to characterize the aroma and lipid profile in grain-fed and grass-fed beef, as well as to identify key lipid molecules and biological pathways linked to aroma formation. Multi-omics analysis revealed that triglycerides (TG(16:0_14:1_18:1), TG(16:0_16:0_18:1), TG(16:0_16:1_18:1), TG(16:0_18:1_18:1), TG(16:0_18:1_18:2), and TG(18:0_16:1_18:1), et al.), diacylglycerols (DG(16:0_18:1) and DG(18:1_18:1)), and free fatty acids (FA(16:1), FA(18:1), FA(18:2), FA(20:3), and FA(20:4)) molecules containing C14:1, C16:1, C18:1, C18:2, C20:3, and C20:4 fatty chains may serve as key precursors to drive distinct aromas in grain-fed and grass-fed beef. These processes are implicated in triglyceride metabolism and fatty acid metabolism pathways and are potentially regulated by DEGs in the PPAR signaling pathway. Specifically, APOA mediates triglyceride transport via lipoprotein secretion, while SLC27A6 enhances intracellular lipid content by promoting long-chain fatty acid uptake. Our results provide a comprehensive understanding of the aroma characteristics and lipid profiles, establishing a theoretical basis for improving beef quality in both grain-fed and grass-fed production methods.