RESUMO
The objective of this study was to evaluate the effects of three finishing systems based on concentrate and legume-grass pasture on beef. Steers were finished for 91â¯days with an exclusively whole corn grain-based (GRAIN) diet, grazed on legume-grass pasture plus 1.4% of body weight of whole corn grain supplementation (SUPP), or grazed on legume-grass pasture (PAST) only. Lipid and myoglobin oxidation, pH, objective color, and α-tocopherol concentrations were evaluated on M. longissimus thoracis steaks. Dietary treatments did not affect pH and minimally affected protein carbonylation. Steaks from steers fed GRAIN were less red, showed higher lipid oxidation during retail display, and higher metmyoglobin formation from day 7 to 13 when compared to PAST. Levels of α-tocopherol were higher in steaks from steers fed diets containing legume and grass. Inclusion of roughage in finishing diets is essential to maintain retail color and prevent lipid and myoglobin oxidation.
Assuntos
Dieta/veterinária , Fabaceae , Peroxidação de Lipídeos , Metamioglobina/metabolismo , Poaceae , Carne Vermelha/análise , alfa-Tocoferol/metabolismo , Ração Animal , Criação de Animais Domésticos/métodos , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Cor , Fibras na Dieta , Suplementos Nutricionais , Grão Comestível , Humanos , Concentração de Íons de Hidrogênio , Masculino , Músculo Esquelético/metabolismo , Mioglobina/metabolismo , Carbonilação Proteica , Zea maysRESUMO
Pasture-finished beef is becoming more popular among consumers due to concerns related to fatty acid content and sustainable practices. The effects of finishing crossbred steers on legume-grass pasture comprised of oats, ryegrass, and clover (PAST), legume-grass pasture plus whole corn grain (WCG) supplementation (SUPP), and only with WCG (GRAIN) on fatty acids profile, volatile compounds, sensory, and texture attributes were studied. Pasture diets (PAST and SUPP) led to lower n-6/n-3 ratio (Pâ¯<â¯0.001), and highest deposition of C18:2 cis-9 trans-11 (Pâ¯<â¯0.001) in the lean. Beef from steers fed GRAIN had the highest values of volatile compounds associated with lipid oxidation. Off-flavor intensity was significantly greater on beef from steers fed GRAIN when compared to PAST. Overall, muscles from steers finished on PAST and SUPP showed similar attributes but differ when compared to GRAIN. The presence of forage is essential to improve fatty acid profile, decrease volatile compounds associated with lipid oxidation, and minimize off-flavor.