The effect of time of evisceration on pH and certain other characteristics of pork muscle.
During surveys at pig slaughter centres In South Africa. it was noted that at some centres the carcasses were eviscerated within 8 min. post mortem while at other centres only after 35 to 60 min. post mortem. Consequently the influence of time of evisceration on certain meat quality characteristics was investigated with special reference to post mortem muscle pH. Following electrical stunning, 9 Landrace x Large White baconer pigs were eviscerated 8 min. post mortem (controls) and 9 were eviscerated 45 min. post mortem (treated). Muscle pH, temperature, reflectance, rigor and cooking loss were determined. At not one of the stages 0,25; 0.50; 0.75; 1; 2; 3; 4; 5; 6 and 24 h post mortem did the pH of the M. longissimus lumborum or M. semimembranosus differ significantly between treatments. The pH1-values of the M.longissimus lumborum were 6,395 and 6,252 and those of the M. semimembranosus 6,511 and 6,401 for the control and treated carcasses respectively. The pHF values were 5,311 and 5,295 for the M. longissimus lumborum and 5,316 and 5,342 for the M. semimembranosus for the control and treated carcasses respectively. Temperature of the M. longissimu lumborum at 45 min post mortem was 38,4 °C for the control and 39,3°C for the treated carcasses (P< 0,05). Rigor, reflectance and cooking loss did not differ significantly between treatments except in the case of the reflectance of the M. semimembranosus which was 33,1 %for the control and 37,2 %for the treated carcasses (P< 0,05). Late evisceration of carcasses, 45 min. post mortem, can therefore not be regarded as a major factor causing all the important typical characteristics of pale, soft and exudative pork muscle to develop.