LAUSR

A label-free proteomics method was used to explore the effects of differentially expressed proteins on the tenderness of yak rumen smooth muscle during postmortem storage (0, 3 and 7 days) at 3 ± 1 °C. The tenderness improved significantly during storage. A total of 212 differentially expressed proteins were identified by the following comparisons: Day 3 vs.0, day 7 vs.0, and day 7 vs.3. Twenty-eight proteins were correlated with the WBSF of yak rumen smooth muscle. Calpastatin, ADP/ATP translocase 1, zyxin, LMOD1 protein, tropomyosin α-3 chain, thrombospondin-4 and UQCRC1 protein are highly related to smooth muscle tenderness, and thus, they are candidates indicators of yak rumen smooth muscle tenderness during storage. Furthermore, bioinformatics analyses revealed that the identified proteins were related to focal adhesion, vascular smooth muscle contraction, cardiac muscle contraction and necroptosis. The present results could provide proteomic insights into changes in yak rumen smooth muscle tenderness during storage and may be a valuable resource for future investigations.