Meat Science 13 (1985) 1-18 Post-Mortem Energy Metabolism in Bovine Muscles Studied by Non-lnvasive Phosphorus-31 Nuclear Magnetic Resonance Hans J. Vogel & Peter Lundberg Department of Physical Chemistry 2, University of Lund, S-220 07 Lund, Sweden & Stefan Fabiansson,* Hfikan Rud&us & Eva Tornberg Swedish Meat Research Institute, PO Box 504, S-244 00 K~ivlinge, Sweden (Received: 8 April, 1984) SUMMARY Phosphorus-31 Nuclear Magnetic Resonance (31p-NMR) has been utilized to follow non-invasively the post-mortem metabolism of the major phosphorylated metabolites in muscles from beef slaughter carcasses. In addition to adenosine-5'-triphosphate (ATP), creatine phosphate (CP) and inorganic phosphate (Pi) considerable amounts of glucose- andfructose-6-phosphate ( G6P and F6P, respectively) as well as glycerol-3-phosphate ( Glyc3P) were detected. A TP was mainly present as a Mg 2 ÷-A TP complex. Adenosine-5'-diphosphate (ADP) appeared to be mainly bound to muscle proteins. A good quantitative agreement was found for the levels of ATP, CP and sugar phosphates (SP) when estimated by NMR or enzymatic assays. Since the chemical shifts of the Pi and sugar phosphate resonances are a * To whom correspondence should be addressed. 1 Meat Science 0309-1740/85/$03.30 © Elsevier Applied Science Publishers Ltd, England, 1985. Printed in Great Britain