Proteome changes in Neck-arm restraint and Achilles tendon suspensions during early post-mortem aging in cattle

•The myofibrillar structure of muscle was more seriously damaged by neck-arm restraint suspension than Achilles tendon suspension.•A total of 59 differentially expressed proteins (DEPs) were identified to impact meat quality.•Integrating DEPs with gene functions and meat quality-related QTLs, 11 proteins (MYL6B, MYO1A, COL3A1, AFP, CLN6, FGB, GLS2, BAG4, FGG, A2M, WNT10A) were proposed to be candidate biomarkers during the early postmortem aging process. The aging process of beef is impacted by the suspension method and aging time during the postmortem process. The neck-arm restraint (NR) suspension can accelerate the aging of beef carcasses compared with Achilles tendon (AT) suspension. However, the muscle protein changes between these two suspension methods in early postmortem aging are still unclear. This study aimed to investigate the proteomes of longissimus thoracis (LT) muscles between AT and NR suspension methods at 1 h and 72 h postmortem by the multiplexed isobaric tagging technology for relative quantitation (iTRAQ) technique and uncover the critical protein biomarkers of beef quality. A total of 59 proteins were differentially expressed between different suspension methods or postmortem aging times, which were mainly involved in actin cytoskeleton reorganization, actomyosin structure organization, response to calcium ions, and muscle contraction. Through the analysis of protein-protein interaction (PPI), we detected that ALB, APOA1, FGA, and TTN could be served as the hub proteins. Integration with the reported quantitative trait loci (QTL) of beef quality revealed that 30 differentially expressed proteins (DEPs) were involved in 46 QTL, in which, 11 proteins were differentially expressed in both the suspension method and time point comparison groups. We inferred these 11 proteins (MYL6B, MYO1A, COL3A1, AFP, CLN6, FGB, GLS2, BAG4, FGG, A2M, and WNT10A) as the most promising markers for the beef quality during the aging process.