Effects of transport time and rest period on the quality of electrically stimulated male cattle carcasses

Forty-five castrated Nelore-breed male cattle, with average age of 37 months, were randomly chosen. The cattle were submitted to the combination of two transport times (up to 2 It and approximately 5 h) and five rest periods (0 h, 6 h, 12 h, 18 h and 24 h). The carcasses were electrically stimulated. After 24 h postmortem, the average of the ultimate pH in the M. Longissimus dorsi (LD) was considered normal (5.57-5.72) for eight out of nine cattle groups. The shear force (SF) was higher for cattle that were not allowed a rest period (0 h) on both transport times, however it was not significant (p > 0.05). This result was compatible with the sarcomere length (SL), which were shorter for those carcasses. The rest period and transport time had no influence on the L* (lightness) values, but a* (redness) values increased until the 12th hour of rest. The b* (yellowness) value was negative for the cattle without a rest period (0 h) and transported for 5 h. The cattle transported for up to 2 h could be allowed a 6-h rest period only, and the cattle transported for 5 h could be allowed a 12-h rest period without the meat quality being affected significantly. (c) 2006 Elsevier Ltd. All rights reserved.