Proteomic biomarkers of beef colour

Implementation of proteomics over the last decade has been an important step toward a better understanding of the complex biological systems underlying the conversion of muscle to meat. These sophisticated analytical tools have helped to reveal the biochemical pathways involved in fresh meat colour and have identified key protein biomarkers. Until recently, there have been no detailed or critical studies on the role of protein biomarkers in determining meat colour. This review presents an integromics of recent muscle proteomic studies to investigate pathways and mechanisms of beef colour. A database was created from 13 independent proteomic-based studies including data on five muscles and a list of 79 proteins which were significantly correlated with colour traits. The database was subjected to a multistep analysis including Gene Ontology annotations, pathway analysis and literature mining. This report discusses the key protein biomarkers and the biological pathways associated with fresh beef colour. Biomarkers were prioritised by the frequency of identification and the need for future validation experiments is discussed. This review identifies six pathways involved in beef colour including energy metabolism, heat shock and oxidative stress, myofibril structure, signalling, proteolysis and apoptosis. The data-mining of the list of the putative biomarkers showed that certain proteins, such as β-enolase (ENO3), Peroxiredoxin 6 (PRDX6), HSP27 (HSPB1), Phosphoglucomutase 1 (PGM1), Superoxide Dismutase [Cu-Zn] (SOD1) and μ-calpain (CAPN1) were consistently reported by multiple studies as being differentially expressed and having a significant role in beef colour. This integromics work proposes a list of 27 putative biomarkers of beef colour for validation using adapted high-throughput methods.