Physical-chemical composition and fatty acid profile in Longissimus muscle of young bulls from different genetic groups finished in feedlot/Composicao quimica e perfil de acidos graxos do musculo Longissimus de bovinos de diferentes grupos geneticos terminados em confinamento

Physical-chemical composition and fatty acid profile in Longissimus muscle of young bulls from different genetic groups finished in feedlot. This work was undertaken to study the physical-chemical composition and fatty acid profile in the Longissimus muscle of young bulls from different genetic groups finished in feedlot. Forty animals were used, with average age of 22 months, from four genetic groups: NGR (1/4 Nelore vs. 1/4 Guzera vs. 1/2 Red Angus); NSM (1/4 Nelore vs. 1/4 Simental vs. 1/2 Marchigiana); NRL (1/4 Nelore vs. 1/4 Red Angus vs. 1/2 Limousin) and NMM (1/4 Nelore vs. 3/4 Marchigiana). After slaughter and carcass chilling, Longissimus muscle samples were collected between the 12th and 13th ribs. There was no genetic group effect (p > 0.05) on muscle moisture (74.0%), ash (1.0%), crude protein (19.0%) and total lipids (2.0%). The NMM group presented the lowest (p < 0.05) ratio of C14:0, C14:1, C16:0 and the highest ratio of C18:0 and C22:1. The saturated fatty acid ratio (46.0%), monounsaturated fatty acid ratio (45.0%) and polyunsaturated fatty acid ratio (8%) were similar (p > 0.05) among the genetic groups. The AGS/AGI ratio (0.2) was similar. The NMM and NGR groups presented, respectively, the highest (8.5%) and the lowest (5.6%) ratios of n-6 fatty acids and the highest (5.5) and the lowest (4.0) n-6 n-[3.sup.-1] ratio. Key words: meat, fat, n-3, n-6, polyunsaturated acid, saturated acid. Objetivou-se avaliar a composicao quimica e o perfil de acidos graxos do musculo Longissimus de bovinos inteiros de diferentes grupos geneticos terminados em confinamento. Foram utilizados 40 animais, com idade media de 22 meses, oriundos de quatro grupos geneticos: NGR (1/4 Nelore vs. 1/4 Guzera vs. 1/2 Red Angus); NSM (1/4 Nelore vs. 1/4 Simental vs. 1/2 Marchigiana); NRL (1/4 Nelore vs. 1/4 Red Angus vs. 1/2 Limousin) e NMM (1/4 Nelore vs. 3/4 Marchigiana). Apos o abate e resfriamento da carcaca, foram retiradas amostras do musculo Longissimus entre a 12a e 13a costelas. Nao houve efeito (p > 0,05) do grupo genetico sobre as percentagens de umidade (74,0%), cinzas (1,0%), proteina bruta (19,0%) e lipideos totais (2,0%) do musculo Longissimus. O grupo NMM apresentou menor (p < 0,05) percentagem de C14:0, C14:1, C16:0 e maior de C18:0 e C22:1. As percentagens dos acidos graxos saturados (46%), monoinsaturados (45%) e poli-insaturados (8%) foram semelhantes (p > 0,05) entre os grupos geneticos. A razao AGI/AGS (0,2) nao diferiu. Os grupos geneticos NMM e