RESUMO
Muscle fiber morphometry and physicochemical characteristics were evaluated in LT muscles obtained from entire male lambs treated with zilpaterol hydrochloride (ZH, 0 and 0.15 mg/kg body weight) and/or steroidal implant (SI, with and without trenbolone acetate/estradiol). ZH and SI acted synergistically to increase LT area, type-IIb fiber cross-sectional area and soluble collagen content, likewise to decrease metmyoglobin concentration and insoluble collagen content. Ash content and ultimate pH showed a decrease due to an antagonistic effect between ZH and SI. Content of total collagen, protein, fat, moisture, oxidized lipids and water-holding capacity were unaffected by ZH and SI. Supplemental ZH, but not SI, decreased all color parameters and tended to increase shear force. Overall, the SI implantation of male lambs followed by a ZH supplementation promoted greater LT hypertrophy, without affecting protein and fat content, and physicochemical characteristics in their meat.
Assuntos
Fibras Musculares Esqueléticas/efeitos dos fármacos , Carne Vermelha/análise , Compostos de Trimetilsilil/farmacologia , Adrenérgicos/farmacologia , Animais , Cor , Estradiol/farmacologia , Masculino , Músculos Paraespinais/anatomia & histologia , Músculos Paraespinais/química , Resistência ao Cisalhamento , Carneiro Doméstico , Acetato de Trembolona/farmacologiaRESUMO
Industry requires non-destructive real-time methods for quality control of meat in order to improve production efficiency and meet consumer expectations. Near Infrared Hyperspectral Images were used for tenderness evaluation of Nellore beef and the construction of tenderness distribution maps. To investigate whether the selection of the region of interest (ROI) in the image at the exact location where the shear force core was collected improves tenderness prediction and classification models, 50 samples from Longissimus muscle were imaged (1000-2500â¯nm) and shear force were measured (Warner-Bratzler). The data were analyzed by chemometric techniques (Partial Least Squares together with discriminant analysis - PLS-DA). Classification models using local ROI presented better performance than the ROI models of the whole sample (external validation sensitivity for the tough classâ¯=â¯33% and 70%, respectively), but none could be considered as successful model. However, the more general model had better performance in the tenderness distribution maps, with 72% of predicted images correctly classified.
Assuntos
Inspeção de Alimentos/métodos , Qualidade dos Alimentos , Carne/análise , Modelos Biológicos , Músculos Paraespinais/química , Matadouros , Animais , Animais Endogâmicos , Brasil , Calibragem , Bovinos , Análise Discriminante , Estudos de Viabilidade , Inspeção de Alimentos/instrumentação , Análise dos Mínimos Quadrados , Análise de Componente Principal , Reprodutibilidade dos Testes , Resistência ao Cisalhamento , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
The work describes a metalloproteomics study of bovine muscle tissue with different grades of meat tenderness from animals of the Nellore breed (Bos indicus) based on protein separation by two-dimensional gel electrophoresis, the identification of calcium ions in protein spots by X-ray fluorescence (SR-XRF) and the characterisation of proteins by electrospray ionisation mass spectrometry. Forty (40) specimens were selected and divided into two experimental groups: animals with tough meat (TO) and animals with tender meat (TE). A third group (P) of Piedmontese breed animals (Bos taurus) was included to serve as a comparative model for the level of meat tenderness. The procedures were efficient and preserved the metal-protein structure, enabling calcium detection in protein spots by SR-XRF at a given molecular weight range of 14-97kDa. Two proteins (pyruvate kinase and albumin) were inferred to be related to the phenotypical differences in animals from the different groups.
Assuntos
Eletroforese em Gel Bidimensional/métodos , Carne/análise , Músculos Paraespinais/química , Proteínas/química , Proteômica/métodos , Animais , Cruzamento , BovinosRESUMO
Este trabalho foi realizado para avaliar a composição química e o perfil de ácidos graxos do músculo Longissimus de bovinos de três grupos genéticos (ZEB Zebu; LIZ Limousin vs. Zebu e ANZ Angus vs. Zebu) alimentados com silagem de sorgo + 1,0% do peso vivo de concentrado ou cana-de-açúcar + 1,2% do peso vivo de concentrado, e abatidos em dois graus de acabamento (3,4 ou 4,8 mm de espessura de gordura de cobertura). Foram utilizados 36 bovinos com idade de 21 meses e peso médio inicial de 330 ± 44 kg terminados em confinamento após período de 115 ou 147 dias de alimentação. Não foram observadas diferenças (P > 0,05) nos teores de umidade (74,09%), cinzas (0,99%), proteína bruta (21,61%), lipídios totais (1,69%) e colesterol total (37,83 mg/100g de músculo) no músculo Longissimus entre os grupos genéticos e as dietas. O músculo Longissimus de bovinos abatidos com 3,4 mm de gordura de cobertura apresentou maior (P < 0,05) teor de umidade (75,40%) e cinzas (1,03%) quando comparado aos abatidos com 4,8 mm (72,78 e 0,96%, respectivamente). Bovinos do grupo genético LIZ apresentaram maiores concentrações (P < 0,05) de ácido eicosapentaenóico (0,45%) e ômega 3 (0,98%) em relação aos ZEB (0,18 e 0,62%, respectivamente) e ANZ (0,25 e 0,70%, respectivamente). A dieta composta por cana-de-açúcar resultou em maior (P < 0,05) deposição do ácido graxo palmitoléico (3,07%) em relação à dieta composta por silagem de sorgo (2,57%). Este resultado foi obtido em função da maior atividade da enzima Δ9Dessaturase C16 nos bovinos alimentados com cana de açúcar. A silagem de sorgo proporcionou aumento (P < 0,05) na deposição do ácido 22:4 n-6 (0,14%) em comparação à cana de açúcar (0,10%). O grau de acabamento das carcaças não influenciou (P > 0,05) a composição dos ácidos graxos, com exceção para a razão ômega 6/ômega 3. O abate de bovinos com 3,4 mm de gordura de cobertura proporcionou melhor (P < 0,05) razão ômega 6/ômega 3 (7,33 vs. 8,63). A composição química e o perfil de ácidos graxos do músculo Longissimus de bovinos analisados neste estudo apresentam pouca variação em função dos grupos genéticos, dietas e graus de acabamentos.
This study was carried out to evaluate the chemical composition and fatty acid profile of Longissimus muscle of cattle from three genetic groups (ZEB - Zebu, LIZ - Limousin vs. Zebu and ANZ - Angus vs. Zebu) fed sorghum silage + 1.0% of body weight of concentrate or sugar cane + 1.2% of body weight of concentrate and were slaughtered at one of two fat thickness levels (3.4 or 4.8 mm fat thickness). Were used 36 bulls with age 21 months and weighing 330 ± 44.0 kg finished in feedlot after 115 or 147 days. There were no differences in moisture content (74.09%), ash (0.99%), protein (21.61%), total lipids (1.69%) and total cholesterol (37.83 mg/100 g of muscle) among the genetic groups and diets. The Longissimus muscle of animals slaughtered at 3.4 mm of fat thickness had higher moisture content (75.40%) and ash (1.03%) when compared to slaughtered 4.8 mm (72.78 and 0.96%, respectively). Genetic groups LIZ showed higher concentrations of eicosapentaenoic acid (0.45%) and omega 3 (0.98%) compared to ZEB (0.18 and 0.62%, respectively) and ANZ (0.25 and 0.70%, respectively). The diet consists of sugar cane resulted in increased deposition of fatty acid palmitoleic (3.07%) in relation to diet composed of sorghum silage (2.57%). This result was obtained due to higher activity of the enzyme Δ9desaturase C16 in animals fed with sugar cane. Sorghum silage increased the deposition of acid 22:4 n-6 (0.14%) compared to sugar cane (0.10%). The fat thickness levels of the carcasses had no effect on fatty acid composition, except for the ratio omega 6/omega 3. The slaughter of animals with 3.4 mm of fat thickness provided the best ratio omega 6/omega 3 (7.33 vs. 8.63). The chemical composition and fatty acid profile of Longissimus muscle of animals analyzed in this study show little variation in terms of genetic groups, diets and fat thickness levels.