Carcass characteristics and sensorial evaluation of meat from Nellore steers and crossbred angus vs. Nellore bulls [Características de carcaça e avaliação sensorial da carne de novilhos Nelore e touros cruzados Angus vs. Nelore]

This study evaluated animal performance, carcass characteristics and meat quality of 36- month old Nellore steers finished in pastures (n = 10) and 20-month old Angus vs. Nellore bulls finished in feedlot (n = 10). Final body weight, carcass weight, characteristics, conformation and fat thickness, were higher (p < 0.001) for the Nellore steers than for Angus vs. Nellore bulls. Water losses during chilling (24 hours, 4oC) were lower (p < 0.05) for Nellore steers than for the Angus vs. Nellore bulls. Muscle percentage on the 6th rib was higher (p < 0.05) for the Nellore steers than for Angus vs. Nellore bulls; while bone percentage was lower (p < 0.05) for Nellore steers. After 7 and 14 days of ageing, the L* meat value was higher for the Nellore steers than for the Angus vs. Nellore bulls; the L* meat value was similar (p > 0.05) throughout the ageing period for the Angus vs. Nellore bulls, but higher in meat from the Nellore steers (p < 0.05). Genetic group had no effect (p > 0.05) on meat a* value (redness). Likewise, ageing time had no effect on a* in both genetic groups, and genetic group had no effect (p > 0.05) on meat b* value (yellowness). On the other hand, b* was increased after day 7 of ageing for the bulls from the two genetic groups. Thawing and cooking losses were lower for Nellore steers after day 7 of aging (p < 0.05). The meat of the Angus vs. Nellore bulls was more tender (p < 0.05) at all ageing times studied (1, 4, 7 and 14 days) than the meat of the Nellore steers. Genetic group had no effect (p > 0.05) on lipid oxidation; however, lipid oxidation increased after day7. Meat from Nellore steers contained a higher percentage of saturated fatty acids (SFA), a lower percentage of unsaturated (UFA) and monounsaturated fatty acids (MUFA) and a similar percentage of polyunsaturated fatty acids (PUFA) than the meat from Angus vs. Nellore bulls. Intramuscular fat from Nellore steers had a more favourable n-6:n-3 fatty acid ratio than that from Angus vs. Nellore bulls (4.37 vs. 11.45, respectively). Tenderness, flavour and overall acceptability were higher (p < 0.001) for meats of the Nellore steers, regardless of ageing time (1, 4, 7 and 14 days)

Perfil lipídico da gordura intramuscular de cortes e marcas comerciais de carne bovina Lipid profile of intramuscular fat in meat cattle cuts of commercial brands

O trabalho foi realizado para caracterizar a gordura intramuscular dos cortes contrafilé, picanha e costela de seis marcas comerciais (A, B, C, D, E e F) de carne bovina comercializadas no município de Porto Alegre, Rio Grande do Sul. As amostras foram coletadas em uma rede de hipermercados. As marcas A e B foram associadas a animais de raças britânicas, as marcas C e D de animais de raças européias produzidos em sistema convencional e orgânico, respectivamente, e provenientes do Uruguai e as marcas E e F de animais sem raça definida e sistema de alimentação não identificado, obtidas em um frigorífico regional e em uma rede de hipermercados, respectivamente. As amostras foram desossadas, moídas, embaladas a vácuo e armazenadas em temperatura de resfriamento até o momento das análises. Em cada amostra foram realizadas a extração dos lipídios e a identificação dos ácidos graxos. O delineamento experimental foi inteiramente casualizado, com arranjo fatorial 6 × 3 e os dados analisados pelo procedimento GLM do aplicativo computacional SAS. Não houve interação significativa entre cortes e marcas para o perfil lipídico dos cortes comerciais. O percentual lipídico foi de 0,95; 3,01 e 0,97% nos cortes contrafilé, costela e picanha, respectivamente. A costela apresentou maior percentual de ácidos graxos (AG) saturados e maior estimativa da D9 desaturase a partir do C16:0 e C18:0. O maior percentual de C18:2 cis-9, trans 11, ácido linoleico conjugado, CLA, n-6 e n-3 foi encontrado na picanha. A marca F apresentou maior grau de saturação e a marca D, maior valor de ácidos graxos poliinsaturados, relação poliinsaturados/saturados e trans18 e menor valor de ácidos graxos saturados. Houve interação significativa entre corte e marca para o conteúdo de CLA, sendo o maior conteúdo encontrado no contrafilé da marca F. As características da gordura intramuscular da carne bovina dependem do corte e da marca comercial.<br>The objective of this work was to characterize the intramuscular fat of short loin, ramp loin and rib and six commercial brands (A, B, C, D, E and F) of beef commercialized in Porto Alegre, Rio Grande do Sul. Samples were collected from a supermarket chain. The brands A and B were associated with British animals breeds, the brands C and D were from European animals breeds produced in conventional and organic system, respectively, from Uruguay, while the brands E and F were derived from non specific breed and unidentified feeding system, obtained in a slaughterhouse and a regional chain of supermarkets, respectively. The samples were deboned, ground, vacuum packed and stored in cooling temperature until the moment of analysis. In each sample were extracted lipids and fatty acids were identified. The experimental design was a completely randomized, with a 6 × 3 factorial arrangement and analyzed by the GLM procedure of SAS computing application. Regarding lipid profile no significant interaction were found among cuts and brands of commercial cuts. The lipid percentage was 0.95; 3.01 and 0.97% in short loin, ribs and ramp loin cuts. Rib presented the greatest percentage of saturated fatty acids (FA) and the greatest estimate of D9 desaturase from C16:0 and C18:0. The highest percentage of C18:2 cis-9, trans 11, conjugated linoleic acid, CLA, n-6 and n-3 was found in ramp loin. Brand F showed a higher degree of saturation, while the brand D showed higher polyunsaturated fatty acids, polyunsaturated/saturated ratio and trans18 and the lowest saturated fatty acids. There was a significant interaction between cuts and brands for the content of CLA, with the highest content found in the short loin of brand F. The characteristics of intramuscular beef fat depending on the cuts and the commercial brands