The variation in pig muscle glycolytic potential during lairage-an in-vivo study

The variations in glycolytic potential (GP, very close to glycogen content) were studied during lairage in pig m. longissimus dorsi using biopsy sampling. Pigs were sampled on arrival at the abattoor and after treatment. Post-mortem measurements including pH(1), pH(u) and FOP(u) were performed on both longissimus dorsi (LD) and biceps femoris (BF) muscles. The animals underwent one of the following treatments: 2 h lairage mixed or unmixed; 24 h lairage mixed or unmixed with access to water only; 24 h lairage mixed or unmixed with access to a sugar solution. A significant depletion in GP occurred during lairage except when pigs were fed liquid sugar. The extent of this depletion was irrespective of lairage duration or mixing. Pigs lairaged 24 h with access to water only exhibited a significantly lower pH(1) in m. BF suggesting a higher propensity to develop PSE meat. Values of pH(u) were low (pH < 5·5), and did not vary significantly between the treatments since muscle GP remained high, despite the depletion induced by lairage. This was attributed to the high level of muscle glycogen characterizing the Hampshire crossbred pigs used in this experiment. These results suggest that interaction between breed and handling procedure may be important regarding meat pH(u).