Protein lysine acetylation regulates beef color stability during storage

Protein lysine acetylation is reported to be widely involved in the postmortem conversion of muscle to meat, but the detailed mechanism remains to be elucidated. To investigate its influence on meat color, here beef patties were prepared with or without histone acetyltransferase (HAT) or histone deacetylase (HDAC) inhibitors and meat color were measured during storage. The results showed that up-regulation of protein lysine acetylation by HDAC inhibitor improved meat a* values and inhibited myoglobin oxidation during storage. However, downregulation of protein lysine acetylation by HAT inhibitors decreased a* values and increased the content of metamyoglobin in meat, indicating that protein lysine acetylation regulated meat color stability. Subsequently, acetylome was profiled in beef of high and low color stability. The analysis identified 2102 acetylation sites across 596 proteins in bovine muscle. Among these sites, 145 differential acetylation sites were detected between groups H and L, corresponding to 98 differentially expressed acetylated proteins (DEPs). The enrichment analysis revealed that the DEPs were associated primarily with the glycolysis/gluconeogenesis pathway, starch and sucrose metabolism pathway, and carbohydrate metabolism, all of which are related to beef color. Bioinformatic analysis suggested that protein lysine acetylation may regulate beef color stability through the modulation of glycolysis, signal transduction, apoptosis, and muscle contraction post-slaughter. This study provides foundational data and novel insights into the mechanisms underlying beef color stability.