Restriction lift date: 2023-05-30
Proteomic approaches for the identification of biomarkers of beef tenderness from Longissimus thoracis muscles and plasma of young Limousin-sired bulls
University College Cork
The palatability of beef, i.e., tenderness, juiciness, chewiness, and flavour, is an essential predictor of the eating experience of beef consumers. As the leading factor influencing palatability, beef tenderness can vary considerably even for the same breed and muscle type, due to intricate biochemical processes and protein-protein interactions. Recently, proteomic and bioinformatic tools have been applied in meat science to identify biomarkers of beef quality. Nevertheless, there are still gaps in our understanding of the mechanisms lying behind the biomarkers and the biological pathways involved. The work in this thesis firstly assessed the feasibility of RNAlater® as a muscle protein preservation method to facilitate discovery of biomarkers of multiple beef quality traits by proteomic approaches in plasma and Longissimus thoracis (LT) muscles of young Limousin-sired bulls. RNAlater® was shown to be an appropriate way to preserve bovine muscle proteins for downstream proteomic studies. In the following three experimental studies, a total of 66 proteins were identified as candidate protein biomarkers of beef tenderness, of which 37 themselves or their isoforms overlapped with previous databases and 29 were novel markers discovered in this study. Those biomarkers were further classified into six main biological pathways, which included: muscle contraction and structure; energy metabolism; heat shock proteins; oxidative stress; proteolysis; and regulation of the cellular process, apoptosis and transport pathways. More specifically, B2M, AHSG, APOA4 and HP-20 (plasma), PFKM, MYH2, PTER, GSTM1 and MYPN (muscle) were good predictors of tenderness, juiciness and chewiness. Five explanatory models were built to explain various beef quality traits, specifically, MYOZ3, BIN1 and OGN for WBSF; CACNA2D1, EIF5A, STBD1, WDR1 for tenderness; SOD1, PHKA1, ATP5F1C for chewiness; TPT1, SOD1, TPM3, HPX for stringiness; PHKG1, CORO6, ATP5F1A for flavour. Moreover, PHKA1 and STBD1 showed significant correlations with tenderness, chewiness, stringiness and flavour and thus could represent robust biomarkers of beef sensory quality. Overall, the studies conducted in this thesis give a deeper insight into the muscle sampling method, biomarker identification for multiple quality traits, statistical models to predict beef quality, relevance of proteomics in bovine biofluids and the functional interactions involved in biological pathways that influence meat quality. The candidate protein biomarkers identified in this study should be further evaluated and validated in a larger group of animals to provide a solid basis to assist the beef industry in early post mortem prediction of beef quality.
Proteomic , Beef quality , Biomarker , Tenderness , Plasma
Zhu, Y. 2021. Proteomic approaches for the identification of biomarkers of beef tenderness from Longissimus thoracis muscles and plasma of young Limousin-sired bulls. PhD Thesis, University College Cork.