Relationship Between Glycolytic Potential and Meat Quality of Duroc Pigs with Consideration of Carcass Chilling System / Związek potencjału glikolitycznego z cechami jakości mięsa tuczników rasy Duroc, z uwzględnieniem systemu chłodzenia tusz

The objective of this study was to determine phenotypic relations between glycolytic potential (GP) measured 45 min postmortem and meat quality traits of stress-resistant fatteners, with consideration of carcass chilling system. The investigations involved 35 Duroc fattening pigs whose left halfcarcasses were chilled conventionally (4ºC for 24 h) and right half-carcasses were rapidly chilled in a three-phase chilling tunnel (-10ºC for 15 min, -15ºC for 25 min and -5ºC for 40 min with air velocity of 3 m/s). In this study we showed that rapid chilling significantly slows the rate of pH fall from 2 to 96 h after slaughter. The negative relationship between glycolytic potential and pH (especially 24 h postmortem) was stronger for conventionally chilled carcasses but the regression coefficient (b) does not suggest increased rate of pH fall in meat of conventionally chilled carcasses (especially compared to rapid chilling) at the later stages of conversion of muscle to meat (from 24 to 144 h after slaughter). In this investigation GP was positively correlated to drip loss at 48 h postmortem, and a stronger correlation was noted for rapidly chilled carcasses. Moreover, the regression coefficient indicates that rapid chilling to 48 h postmortem can cause a slightly higher drip loss from meat than when the carcasses are chilled conventionally (0.55 vs. 0.46 percentage points per 10 μmol/g GP). At the later stages of conversion of muscle to meat (96 and 144 h postmortem) the correlation and regression coefficients were the same regardless of the chilling system.