Postmortem changes of pH value and lactic acid content in the muscles of pigs and bulls

e development of post-mortal changes was evaluated in m. longissimus lumborum et thoracis (MLLT) and m. semimembranosus (SM) of pigs and in m. longissimus lumborum et thoracis of bulls; both half-car- casses were compared. e lowest value of pH in MLLT of pigs was measured 36 h after slaughter (5.52) in the right side and 48 h in the left side of pork (5.48). e highest concentration of lactic acid was recorded 24 h post mortem (109.78 and 109.22 mmol/kg). e decrease in pH values in SM was slower while the lowest values 5.68 and 5.79 were found 48 h post mortem. An increase in lactic acid concentration was analogous to MLLT, but the amount of produced acid was lower. Differences between the right and the left side were not statistically significant. Significant differences were found between the muscles ( P < 0.01). e lowest values of pH in MLLT of bulls were measured 48 h after slaughter (5.43 and 5.42). e maximum concentration of lactic acid was found 72 h after slaughter (113.33 and 116.00 mmol/kg). e differences between both sides of beef were not statistically significant. e correlation coefficients between pH value and lactic acid concentration were -0.87 ( P < 0.01) for MLLT and -0.78 (P < 0.01) for SM in pigs, and -0.96 (P < 0.01) for MLLT in bulls.