Glycogen Supplementation in Vitro Promotes pH Decline in Dark-Cutting Beef by Reverting Muscle's Metabolome toward a...

Area of Science:

• Animal Science
• Biochemistry
• Food Science

Background:

• Dysregulated muscle glycogen metabolism preslaughter is linked to dark-cutting beef phenotypes.
• The specific mechanisms driving aberrant postmortem muscle pH in these cases are not fully understood.

Purpose of the Study:

• To investigate the role of glycogen in regulating postmortem muscle pH decline and meat darkening in beef.
• To explore strategies for mitigating dark-cutting beef by manipulating glycogen levels.

Main Methods:

• In vitro supplementation of glycogen to dark-cutting beef muscle.
• Metabolomic analysis to assess changes in muscle metabolites.
• Enzyme activity assays for glycogen phosphorylase and lactate dehydrogenase.
• Inhibition of mitochondrial respiration complexes.

Main Results:

• Glycogen supplementation restored normal postmortem pH decline in dark-cutting beef.
• Metabolomic profiles shifted towards a typical postmortem muscle state with increased glycolytic metabolites.
• Enzyme activities of glycogen phosphorylase and lactate dehydrogenase were enhanced.
• Inhibiting mitochondrial respiration alongside glycogen supplementation further increased pH decline.

Conclusions:

• Supplementing glycogen (10 mM) can reprogram the metabolome of dark-cutting beef muscle, promoting acidification.
• Enhancing muscle glycogen levels is a potential strategy to mitigate dark-cutting beef and improve meat quality.