Ultrasonication improves beef flavor characteristics by modifying precursor metabolite profiles: Emphasis on superior efficacy of pre-rigor processing

This study investigated the effects of ultrasonication (US, 20 kHz at 600 W for 30 min) applied at different postmortem stages, including pre-rigor (0.5 h) and post-rigor (24 h), on beef flavor characteristics during subsequent aging, and further elucidated its underlying mechanisms through integrated metabolomics. Sensory evaluation and electronic nose analyses demonstrated that pre-rigor US treatment significantly altered flavor profiles and enhanced overall acceptability compared with post-rigor US and non-US control (CON) groups. Further analysis revealed that beef subjected to pre-rigor US exhibited the highest abundance and diversity of volatile organic compounds, particularly characterized by 1-octen-3-ol, octanal, and 2-pentylfuran. Furthermore, abundant lipid molecules (e.g., phosphatidylethanolamine (PE), phosphatidylinositol (PI), and lysophosphatidylcholine (LPC)), along with enriched pathways in glycerophospholipid and nucleotide metabolisms, were typically identified in US-treated beef, particularly pre-rigor US. These critical precursors and metabolic pathways were primarily responsible for the superior flavor performance observed. Collectively, these findings demonstrated pre-rigor US technology as a potential strategy for improving beef flavor profiles during postmortem aging.