Proteomic biomarkers of beef colour

peer-reviewedBackground 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. Scope and approach 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. Key findings and conclusions 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.FI

Relationship Between Feeding, Stereotypies, and Plasma Glucose Concentrations in Food-Restricted and Restrained Sows

Previous work has shown that stereotypies, such as chain manipulation and excessive drinking, only develop in food-restricted sows. Furthermore, once stereotypies have been developed, ingestion of a small meal specifically stimulates the performance of stereotypies. These results suggest that the occurrence of stereotypies may strongly depend on the individual's nutritional status. As glucose is one of the main metabolic fuels, the present experiment investigated whether individual differences and/or daily variations in levels of chain manipulation and excessive drinking are correlated to individual differences and/or daily variations in pre- or postfeeding glucose concentrations. Blood samples were taken at regular intervals prior to, during, and after feeding, from sows that had developed stereotypies to different degrees over a period of 110 days of restrictive housing and feeding conditions. Glucose concentrations were low prior to and high after feeding. Levels of stereotypies showed similar variations, suggesting that the performance of stereotypies is not related to low glucose concentrations. Furthermore, whilst sows differed consistently in glucose concentrations, no correlations were found between individual glucose concentrations and stereotypies. Similarly, no correlations were found between glucose concentrations and chain manipulation or drinking on a sample to sample basis. These data show that although performance of stereotypies is strongly dependent on feeding regime, it is not related to plasma glucose concentrations.

Dark-cutting beef: A brief review and an integromics meta-analysis at the proteome level to decipher the underlying pathways

Comprehensive characterization of the post-mortem muscle proteome defines a fundamental goal in meat proteomics. During the last decade, proteomics tools have been applied in the field of foodomics to help decipher factors underpinning meat quality variations and to enlighten us, through data-driven methods, on the underlying mechanisms leading to meat quality defects such as dark-cutting meat known also as dark, firm and dry (DFD) meat. In cattle, several proteomics studies have focused on the extent to which changes in the post-mortem muscle proteome relate to dark-cutting beef development. The present data-mining study firstly reviews proteomics studies which investigated dark-cutting beef, and secondly, gathers the protein biomarkers that differ between dark-cutting versus beef with normal-pH in a unique repertoire. A list of 130 proteins from eight eligible studies was curated and mined through bioinformatics for Gene Ontology annotations, molecular pathways enrichments, secretome analysis and biological pathways comparisons to normal beef color from a previous meta-analysis. The major biological pathways underpinning dark-cutting beef at the proteome level have been described and deeply discussed in this integromics study