Proteomics discovery of protein biomarkers linked to yak meat tenderness as determined by label-free mass spectrometry

Tenderness is one of the most important qualities in meat. A proteomic approach is a suitable way to ensure meat tenderness. Thirty-six tenderloin samples from yak were classified as exhibiting high (n = 12) or low (n = 12) tenderness and were evaluated using label-free proteomics for the identification of the proteins and pathways most influential in tenderness variability. Between the two groups, proteomic changes were mainly caused by 33 differentially expressed proteins as displayed in reference patterns in heat maps. The expression of ENO2, SUCLG2, ETFDH, PGM1, TNNT3, TNNT1, HSDL2, GPI, ALAD, and COL1A1 proteins was very different between yak meats with high and low tenderness, and therefore, they are candidate biomarkers of yak meat tenderness. Furthermore, bioinformatics analyses revealed that the identified proteins are related to pentose phosphate, glycolysis, the citrate cycle, fatty acid metabolism, and the calcium signaling pathway.