The effect of breed-production systems on the myosin heavy chain 1, the biochemical characteristics and the colour variables of Longissimus thoracis from seven Spanish beef cattle breeds

The effect of breed-production system on the myosin heavy chain 1 (MHC-1), the biochemical characteristics and the colour variables of longissimus tho racis (LT) from seven beef breeds was studied: Asturiana de la Montana (AM) , Asturiana de los Valles (AV), Avilena-Negra Iberica (A-NI), Bruna dels Pi rineus (BP), Morucha (MO), Pirenaica (PI) and Retinta (RE) (Age at slaughte r between 368 and 541 days; carcass weight between 249 and 334 kg). Signifi cant differences between breed-production systems were found for all traits evaluated. LT from the MO, a rustic type breed, was the most oxidative (MH C-I, 39.3%; isocitrate dehydrogenase activity, 52 nmol min(-1) mg(-1); pigm ent content, 188.4 mug acid haematin g(-1)) and showed a low L* value (32.6 ) and high a* and C* values (24 and 27.2, respectively). In terms of meat c olour (L* and a*) the canonical discriminant analysis separated the breeds into two groups, the AV, the PI and the A-NI (the lightest ones) from the A M and the MO breeds (the reddest and darkest) whereas the BP showed an inte rmediate position. The RE and the A-NI were distinguished From the others b y their high intramuscular fat content. Meat colour was affected by the mus cle biochemical traits in the breed-production systems studied. (C) 2001 El sevier Science Ltd. All rights reserved.