The aim of this work was to study the effect of time between adrenaline injection and slaughter on the rate and extent of post-mortem metabolism in pig muscle. Five pigs were subcutaneously injected with adrenaline (0·3 mg/kg) or with a saline solution 4 h, 1 h or 15 min prior to slaughter. pH1, pHu and FOPu were measured in Longissimus dorsi (LD) and Biceps femoris (BF) muscles. m.LD samples were taken 20 days before slaughter using biopsy sampling, immediately after bleeding and 45 min post mortem for biochemical analysis. m.LD glycolytic potential (very close to glycogen content) was decreased by the injection of adrenaline 4 h and 1 h prior to slaughter, when comparing values at rest (20 days before slaughter) and values determined immediately after bleeding. The depletion was greater fro the injection performed 4 h before slaughter. In this group pHu was higher foe adrenaline-injected pigs (5·69 versus 5·47 for pigs injected with saline solution) but the difference was not significant. Pigs injected with adrenaline 1 h prior to slaughter exhibited higher glucose, glucose-6-phosphate and lactate levels immediately after slaughter, lower pH1 and higher FOP values in m.LD than control pigs. Since the differences in pH1 were not explained by differences in the rate of build-up of lactate, it was hypothesized that pigs injected with adrenaline 1 h prior to slaughter had lower muscle pH at slaughter. It was concluded that the rate or the extent of post mortem metabolism in pig muscle may be affected independently, by manipulating the time between adrenaline injection and slaughter.
|Status||Published - 1992|