Application of GC-IMS, GC-MS, and LC-MS/MS techniques to a comprehensive systematic study on the flavor characteristics of different muscles in the yak

This study aims to explore the key metabolites and metabolic pathways related to the formation of flavor in yak meat, laying the foundation for in-depth analysis of the composition of yak meat and improving meat quality. This study selected six healthy 4-year-old male Tianzhu white yaks under the same growth conditions as the research subjects. The metabolites of three groups of longissimi dorsi (LD), triceps brachii (TB), and biceps femoris (BF) were analyzed and identified using gas chromatography–ion mobility spectrometry (GC-IMS), gas chromatography-mass spectrometry (GC-MS), and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that Tianzhu white yak meat contains abundant metabolites, and the VOC levels in BF muscles are higher than those in LD and TB muscles. The levels of 1-penten-3-one and 2-pentone in LD muscle are higher than in BF and TB muscle. The levels of 2-hexanol, 2-hexanol-D, and pyridine in TB muscles are higher than those in LD and BF muscles. The content of benzaldehyde, benzaldehyde D, 3-hydroxy-2-butane-D, 3-hydroxy-2-butanone, and mesitylene in BF muscle is higher than in LD and TB muscle. There is a significant difference in the enrichment degree of the glycolysis or gluconeogenesis pathways between LD muscles and the other two groups (BF and TB muscles). There were significant differences in the enrichment degrees of the D-glutamine and D-glutamate metabolic pathways, the alanine, aspartate, and glutamate metabolic pathways between the TB muscles and the other two groups (BF and LD muscles). There is a significant difference in the enrichment degree of the niacin and nicotinamide metabolic pathways between BF and LD muscles. In addition, there were significant differences in the enrichment degree of the histidine metabolism pathway among the three groups of muscles. This study identified key metabolites related to differences in meat quality and flavor formation in different parts of the muscle tissue of Tianzhu white yak through metabolomics analysis, providing a theoretical basis for exploring the molecular regulatory mechanism and molecular breeding of yak meat flavor formation in the future, and also providing a reference for quality trait breeding in other beef cattle.