Glycolytic potential of the muscle – effect on pork quality

Color and water holding capacity are important quality parameters of pork. They are in part affected by the glycolytic potential (GP) of the muscle tissue. This trait refers to the intra vitam glycogen content of muscle and is defined as the potential of lactate production during post mortem glycolysis. Muscle GP depends on the muscle considered and is higher in white than in red muscles. A study was carried out to determine the GP in a white (longissimus dorsi: LD) and a red (serratus ventralis: SV) muscle of three breeds (Swiss Landrace: SL, Large White: ES, Duroc: DU) used in Switzerland. Independently of the breed and the sex, pH determined 24 h post mortem (pHu) was higher by 0.1 unit in the SV (pHu = 5.6) compared with the LD. DU had significantly higher pHu (5.5) compared with animals of the other two breeds (pHu = 5.4, P = 0.02). Regardless of these differences, GP within muscle did not differ between the breeds. GP of the SV was lower than in the LD (P < 0.05) and varied in the LD and SV between 122.6 (DU) and 129.6 ?mol/g (SL) and 106.6 (DU) and 113.6 ?mol/g (SL), respectively. As expected GP and pHu were significantly correlated (LD: r = -0.39, SV: r = -0.47). In an additional study with ES pigs, we studied the effects of the GP determined in the LD and dark part of the semitendinosus (ST) on the Minolta lightness (L* score) and drip loss. Lightness (r = 0.52) and drip loss (r = 0.77) were positively correlated with the GP of the ST. With decreasing GP, meat was less pale and retained more water. Unexpectedly, in the LD no significant correlations were found, although the same tendency was seen for the water holding capacity as reported for the ST.