Changes in volatile flavor of yak meat during oxidation based on multi-omics

Hydroxyl radical system combined with GC-IMS and metabolomics were used to assess the effect of oxidation on the formation of volatile flavor emitted from yak meat. The formation of volatile compounds, including heptanal, octanal, nonanal, 2,3-glutaraldehyde, 3-hydroxy-2-butanone, etc. were promoted by oxidation. Among them, 2,3-pentanedione and 3-hydroxy-2-butanone, etc. maybe contributed most to the overall aroma of yak meat, while octanal, nonanal and benzaldehyde maybe related to the formation of off-odor or acidification. Meanwhile, the content of metabolites such as oleic acid, linoleic acid, etc. fatty acids and 3-dehydromangiferic acid, tyrosine were increased or decreased with the time of oxidation. More importantly, the formation of most flavor components in yak meat during the course of oxidation were related to stearidonic acid, acetylleucine, dehydroshikimate, 6-phosphate-glucose etc. differential metabolic components. Moreover, starch and sucrose metabolism (prediction), and amino acid metabolism (enrichment) etc. pathways maybe related with the process of oxidation.