The aim of this review is to address some characteristics that influence meat quality. Genetic groups, nutrition, finishing systems and gender are the major factors that change carcass characteristics, chemical composition and fatty acid profile. Genetic groups that have zebu genes in their composition show higher hot carcass dressing than genetic groups without zebu genes. Genetic groups that have European breeds in their composition have higher marbling scores. On the other hand, genetic groups that have zebu breeds show low marbling scores. Bulls finished in feedlots present higher final weight than steers, cull cows and heifers. Fat thickness is one of the principal parameters that are affected by different gender. Cull cows (4.72 mm) and heifers (4.00 mm) present higher values than bulls (1.75 mm) and steers (2.81 mm). The major effects observed by different systems of termination are fat thickness and marbling. Crude protein presents variation due to nutrition. Nutrition influences variation of fatty acid profile. Genetic groups also influence fatty acid profile. Genetic groups that have zebu genes in their composition show high percentage of PUFA. The major class of fatty acids that is changed with nutrition is PUFA. The better ratios of PUFA/SFA and n-6/n-3 are found in Longissimus muscle of animals finished in pasture systems.

The effects of an alginate-based edible coating containing natural antioxidants (rosemary and oregano essential oils) on lipid oxidation, color preservation, water losses, texture and pH of beef steaks during 14 days of display were studied. The essential oil, edible coating and beef antioxidant activities, and beef consumer acceptability were also investigated. The edible coatings decreased lipid oxidation of the meat compared to the control. The coating with oregano was most effective (46.81% decrease in lipid oxidation) and also showed the highest antioxidant activity. The coatings significantly decreased color losses, water losses and shear force compared to the control. The coatings had a significant effect on consumer perception of odor, flavor and overall acceptance of the beef. In particular, the oregano coating showed significantly high values (approximately 7 in a 9-point scale). Active edible coatings containing natural antioxidants could improve meat product stability and therefore have potential use in the food industry.

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ABSTRACT

O objetivo deste trabalho foi avaliar a substituição do milho pela casca, farinha de varredura ou raspa de mandioca sobre ganho médio diário, consumo e conversão alimentar e rendimento de carcaça de novilhas confinadas. Foram utilizadas 28 novilhas mestiças, com aproximadamente 24 meses de idade e peso médio inicial de 365 kg, distribuídas em um delineamento em blocos casualizados, em um experimento de 56 dias, com quatro tratamentos e sete repetições. Não houve efeito da substituição do milho pelos produtos da mandioca sobre ganho médio diário, conversão alimentar e rendimento de carcaça. No entanto, o consumo foi inferior nas rações contendo raiz e resíduos da mandioca.

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This study was carried out to evaluate fi nal weight, carcass characteristics, chemical composition and fatty acid profi le in Longissimus muscle

Twenty-seven animals (½ Angus - ½ Nellore) were fed for four months with one of the following diets: without addition of essential oils (E0.0), with 3.5 (E3.5) or 7 (E7.0) g/animal/day of an essential oil blend (oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange). Chemical composition, fatty acid profile and meat color were evaluated in Longissimus muscle. In addition, the effects of aging (one, seven and 14days) on the meat water holding capacity, texture and lipid oxidation were evaluated. Essential oils had no effect on chemical and fatty acid composition, meat color, water holding capacity or texture, but an inclusion of 3.5g/day decreased lipid oxidation. The addition of 7.0g/animal/day had a pro-oxidant effect on meat during aging and resulted in higher values for lipid oxidation at 14days of aging. Aging significantly affected thawing losses and texture. A dose of 3.5g/animal/day could be recommended in feedlot animals, but greater doses could have a pro-oxidant effect.