**4. Conclusions**

In this study, it can be concluded that the meat characteristics of di fferent beef muscles responded di fferently to the storage time and were significantly a ffected by carcass position. The meat quality parameters of IN muscle were improved, which was due to its higher pH value, lower MFI and TPS, and greater degree of myofibril rupture, followed by ST and RH. However, there is little di fference in meat quality parameters among other muscles. Therefore, for IN, it can be suggested that the characteristics are particularly suitable for producing high-quality beef products. Additionally, a significant interaction between pH and protein solubility was observed. Further research should be conducted to explore the mechanism of how pH a ffects protein solubility (for example, to assess its e ffect on cathepsin activity).

**Author Contributions:** Conceptualization, S.-S.Z.; methodology, Y.-H.F. and K.-X.W.; software, C.-C.X.; validation, C.-C.X.; formal analysis, C.-C.X. and S.-S.Z.; investigation, P.X.; resources, Y.-H.F.; data curation, Y.-H.F.; writing—original draft, Y.-H.F.; writing—review and editing, C.-C.X.; visualization, B.-Z.S.; supervision, S.-S.Z.; project administration, C.-C.X.; funding acquisition, P.X. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was funded by grants from the Program of National Beef Cattle and Yak Industrial Technology System (CARS-37) and the Modern Agricultural Industry Technology System and Beef Industry Innovation Construction Project of Hebei Province (HBCT2018130204).

**Acknowledgments:** The authors thank Haipeng Li for their valuable assistance during the muscle sampling work.

**Conflicts of Interest:** We declare that we have no conflict of interest.
