Alpine Meadow Habitat Is Associated with Characteristic Flavor Formation in Bayinbuluke Sheep Meat Through Metabolic Reprogramming

This study elucidates the biochemical mechanisms by which extreme high-altitude environments are associated with the remodeling of the skeletal muscle flavor profile in sheep. Using Bayinbuluke (high-altitude) and Turpan Black (low-altitude) sheep, we integrated volatilomics, metabolomics, transcriptomics, and proteomics to map flavor precursor networks. Odor activity value analysis revealed that high-altitude meat exhibited sub-threshold suppression of animal off-flavors, such as p-cresol, while significantly amplifying premium fruity esters. Targeted metabolomics attributed this sensory inversion to a structural shift in the precursor pool, specifically the enrichment of highly reactive polyunsaturated fatty acids, L-cysteine, and rhamnose. Multi-omics integration demonstrated that cold and hypoxic stresses are associated with metabolic reprogramming. The synergistic downregulation of the GPAT3 gene and APOC3 protein was associated with redirected lipid flux, suggesting a mechanism for functional fatty acid accumulation. Simultaneously, the pronounced upregulation of the CTH gene, potentially driven by antioxidant defense needs, coincided with substantial L-cysteine accumulation. Correlation networks suggested that this precursor shift is negatively correlated with off-flavor generation, possibly via competitive thermal degradation. In conclusion, extreme ecological stress is associated with convergent metabolic reprogramming, contributing to the reconstruction of the flavor precursor pool to alter the characteristic lipid aroma of plateau meat. While these findings provide a comprehensive structural blueprint of plateau meat characteristics, the proposed mechanisms remain hypothetical and warrant future functional and sensory validation.