Post-mortem variation in pH, temperature, and colour profiles of veal carcasses in relation to breed, blood haemoglobin content, and carcass characteristics

A total of 1764 male calves of the Meuse-Rhine-Yssel (MRY) and Friesian-Hol stein (FH) breeds were slaughtered at two commercial slaughterhouses to inv estigate the variation in pH, temperature, and colour of Dutch veal carcass es processed without electrical stimulation and with a moderate chilling re gimen (average temperature of the longissimus lumborum muscle at 45 min, 3, 24, and 48 h post-mortem was 38.4, 23.3, 3.7 and 1.9 degrees C, respective ly). Blood haemoglobin content was determined 2 weeks before slaughter. The efficacy of captive bolt stunning was scored and the carcass movements aft er shackling registered. Temperature and pH measurements were carried out a t 45 min, and 3, 24, and 48 h after slaughter in the longissimus lumborum m uscle (LL). Muscle surface colour (CieLAB-values) was measured with a color imeter at the rectus abdominis muscle at the same times post-mortem. Carcas s conformation and visual carcass colour classification were determined at 45 min post-mortem. Carcasses with a better EUROP-conformation score and he avier weight showed a higher rate of pH decline and a slower cooling rate. Slight differences in cooling systems between the slaughterhouses caused ma rked differences in pH and temperature profiles. Significant differences in carcass weight were observed between the MRY and FH breeds, leading to sig nificant differences in pH and temperature profiles. Carcass colour of the two breeds was similar. Veal carcass colour in general was not related to t he observed variation in postmortem pH and temperature in the longissimus l umborum muscle and was shown to be more associated with the blood haemoglob in content. Haemoglobin content of the blood in the period before slaughter was shown to be related to the visually assessed carcass colour at 45 min post-mortem (using a 10-colour scale), as well as to the instrumentally det ermined L*-value, with significant correlation coefficients of 0.61 and -0. 61, respectively. Repeated captive bolt stunning to obtain unconsciousness significantly decreased pH at 3 h post-mortem. The degree of carcass moveme nt after slaughter did not influence pH, temperature, or colour profiles of the carcasses. (C) 1999 Elsevier Science Ltd. All rights reserved.