Investigating biomarkers, biochemical changes and metabolomic features associated with high ph lamb meat

Abstract

In the meat industry, pH is the primary measure to determine if meat has undergone the proper muscle-to-meat conversion. When the pH is high, there has been an insufficient reduction in the pH, resulting in undesirable meat quality traits. Several factors including muscle type, animal age, animal sex, and exposure to low-impact exercise stress can impact meat quality. Lincoln University has a low-impact exercise/high pH stress model that can consistently produce lamb meat with high pH, representing poor quality meat products; allowing for investigating the potential of different ways to determine meat quality. Phosphoglucomutase 1 (PGM1), Pyruvate Kinase (PKM2), Beta Enolase (ENO3), and Phosphoglycerate Kinase 1 (PGK1) are enzymes in the glycolytic pathway shown potential as biomarkers for meat with high pH, therefore investigating how they differ between control and low-impact exercise stress animals will help to determine if they are viable for measuring meat quality. Glycolytic proteins were analysed using western blotting methods on 10 control and 10 exercise stress animal’s samples of Longissimus lumborum (LL), Gracilis (G), Semimembranosus (SM), Supraspinatus (SS), with Glyceraldehyde 3-phopshate dehydrogenase (GAPDH) as a loading control. Rapid Evaporative Ionisation Mass Spectrometry (REIMS) is a novel technology that ‘burns’ tissue samples to produce an aerosol which detects metabolites and their adducts in a mass spectrometer to create a metabolic fingerprint of the sample. REIMS has been applied in-line at a slaughterhouse for the detection of boar taint as a proof of principle, proving that it has the potential to be applied for meat quality measures. Therefore, using data produced during REIMS from animal tissue in the low-impact exercise/high pH stress model to develop a machine learning model to classify groups based on high pH will help to determine the potential of REIMS for online, rapid assessment of meat quality in the meat industry.