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Nutritional quality of beef: from oxidizability to health promoting value

Beef contains valuable nutrients necessary for development of the body and maintenance of good health in humans. Its protein is of high biological value and it also contains essential minerals such as selenium, zinc and highly bioavailable heme iron. Beef is an invaluable source of vitamin B12, the lack of which in the diet causes retarded brain development in infants and anemia in adults. Beef is also a valuable source of important fatty acids such as the polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA). Recent work has discovered that beef can be a source of certain peptides generated during digestion, which act as antioxidants, and antihypertensive factors, and which counteract the loss of muscle mass frequently observed in the elderly

From the fatty acid content perspective, is it healthier to eat a hindquarter or a forequarter cut? Angus steers in pasture or concentrate systems

In this study, Biceps femoris (BF) and Triceps brachii (TB) of Aberdeen Angus steers, from the hindquarter and forequarter, respectively, were compared from their fatty acid composition, lipid health, and lipid enzyme activity indices points of view. For this, ten animals were produced in a pasture system and ten were finished in a concentrate-based system. TB presented a significantly higher intramuscular fat, saturated C14:0, C14:1, C16:1, CLA, and MUFA content. BF presented a significantly higher LA, ARA, EPA, DPA, DHA, PUFA, total n-6, and n-3 content, and a significantly higher PUFA/SFA ratio. Significant differences between muscles were found regarding lipid enzyme activity indices, but not concerning atherogenic and thrombogenic indices. Also, meat from different feeding systems was compared, where meat from pasture presented a better fatty acid composition regarding cardiovascular health aspects. In conclusion, BF presented a better composition in the most nutritionally relevant fatty acids, with exception of CLA

Oxidative stability, fatty acid composition and health lipid indices of Longissimus dorsi muscle from Aberdeen Angus steers produced in different feeding systems

The aim of this study was to evaluate the oxidative and anti-oxidative status of unaged and aged Longissimus dorsi (LD) muscle obtained from a commercial abattoir. Also, fatty acid composition and calculated health lipid indices of meat were compared. Animals slaughtered were Aberdeen Angus steers raised in three typical feeding systems of Uruguay: (1) Pasture (n=10), (2) Pasture + Supplement (P+S) with corn grain (n=10), and (3) Feedlot (n=10). Feeding had no effect on lipid and protein oxidation but the antioxidant enzymes activities were affected as follows: superoxide dismutase (SOD): Pasture, Feedlot > P+S; catalase: Pasture > P+S, Feedlot; glutathione peroxidase (GPx): Feedlot > P+S > Pasture. Total antioxidant potential, determined by Fenton reaction, was higher in aged meat from Pasture compared with aged meat from Feedlot. Meat from Pasture and P+S presented a higher eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and total n-3 content and a lower lipid content, n-6/n-3 ratio and trombogenic index compared to meat from Feedlot. In conclusion, Pasture seems to produce a more resistant meat against induced oxidation processes, particularly after ageing, and a healthier meat together with meat from P+S system, regarding fatty acid composition and lipid indices, compared to Feedlot

Herramientas nutricionales para la obtención de productos aviares funcionales

El huevo y la carne aviar son alimentos estratégicos y completos, por su altísima calidad proteica, contenido de lípidos, composición en ácidos grasos y contenido en minerales necesarios para el desarrollo de los niños y la alimentación de personas con altos requerimientos nutricionales, mujeres embarazadas, deportistas y en la etapa de la vejez

Nutritional quality of the beef produced in Uruguay

Meat from bovines is an important item in the human diet. This is related to the availability in beef of nutrients such as the essential amino acids, fatty acids and micronutrients, most of which have a highly available biochemical form. In Uruguay, beef production is of great economic relevance and includes operations based on the use of pastures and others using grain supplementation and feedlots. Consequently, it’s important for beef producers to know the nutritional quality of this meat in order to promote their products in the international market. Knowledge about the nutritional quality of beef can also help consumers to choose what kind of meat they prefer to promote better health. The present review of the literature presents data concerning the nutritional quality of beef produced in Uruguay

Catalase, SOD and GPx Activities in triceps brachii muscle from Aberdeen Angus steers finished on pasture, pasture and concentrate, or concentrate

Three feeding system were investigated to determine if any of them is more suitable to ensure a better antioxidant protection to meat from Triceps brachii muscle of Aberdeen Angus steers. They were finished on pasture, pasture + concentrate with corn grain, or concentrate alone. TBARS, protein carbonyls and antioxidant enzymes activities have been determined in fresh and aged meat (14 days in vacuum, 1-2°C). The level of TBARS ranged between 0.59-0.64 mg MDA/kg meat, whereas levels of protein carbonyl ranged between 0.18-0.22 mmoles DNPH/mg protein. The activities of catalase and superoxide dismutase are higher in fresh meat of animals fed pasture, compared to those finished on pasture and concentrate, or on concentrate alone. Glutathione peroxidase (GPx) showed higher activities in meat of animals finished on concentrate in comparison those finished on pasture and concentrate, or pasture. However, the results of the investigation do not allow the advising, for now, for the most suitable feeding system for finishing steers that help producers to preserve meat from lipids and protein oxidation. More investigations are necessary to highlight the feeding conditions, which could influence the activities of antioxidant enzyme catalase, SOD and GPx in meat

A note on fatty acids profile of meat from broiler chickens supplemented with inorganic or organic selenium

This investigation evaluated, in broiler chickens Pectoralis and Gastrocnemius muscles, the effect of the dietary supplementation with sodium selenite (0.3 ppm) versus selenomethionine (0.3 ppm), on the fatty acids composition, lipids indices, and enzymes indexes for desaturase, elongase, and thioesterase. The selenium reduced, in both muscles, the content of atherogenic fatty acids, C14:0 and C16:0, while it increased the C18:1 level. On the other hand, selenium increased, in both muscles, the content of C18:3n3 and EPA, but not DPA and DHA. No selenium effect was detected for PUFA/SFA, n-6, n-3, n-6/n-3, and atherogenic and thrombogenic indices. As for the enzyme indexes, a selenium effect is only detected for thioesterase. Taken together, the results highlight the potential effect of dietary selenium, mainly selenomethionine, in the modulation of the composition of fatty acids in chicken meat, in particular, reducing the content of atherogenic fatty acids and increasing the health promoting n-3 PUFA

Se and I status in pregnant ewes from a pastoral system and the effect of supplementation with Se and I or only Se on wool quality of lambs

Australian Merino ewes and lambs producing fine fibre wool for export are raised in the north-west of Uruguay in pasture-based systems. We studied the status of selenium and iodine in pregnant Merino ewes (10 per treatment) grazing in natural pasture, in natural pasture and supplemented with Se (0.1 mg Se/kg dry matter intake) and I (1 mg I/kg dry matter intake), or in natural pasture and supplemented with Se alone (0.1 mg Se/kg dry matter intake), during the last 30 days of gestation. Further, we evaluated the performance and wool quality of their offspring. Content of Se and I in natural pasture, in the sera of pregnant ewes, and in the wool of their offspring and levels of thyroidal hormones—TSH, T4, and free T3 (FT3)—in the sera of pregnant ewes were determined. The performance of lambs and the commercial parameters of fine fibre wool produced were measured. Results showed normal Se levels in serum (0.12–0.15 mg/l) in the ewes grazing in natural pasture (0.07–0.09 mg/kg DM) during late pregnancy. The observed increase in Se content in the pasture at lambing (0.11–0.16 mg/kg DM) improved serum Se levels (0.216 mg/l); however, the serum levels were not affected by the supplementation. I content in pasture showed adequate levels (0.50–0.60 mg/kg DM), which were reflected in the blood serum values 30 days prior to lambing (0.197–0.208 mg/l). However, at lambing, the I content in blood serum decreased (0.150 mg/l). Further, the supplementation did not modify the serum I levels (0.163–0.175 mg/l). An increase in FT3 levels in ewes at lambing could be associated with the increase in Se content in pasture and/or the adequate I content in pasture. No effect of supplementation was observed. Lambs showed good results regarding the quality of fine fibre wool and performance after supplementation with Se and I or Se alone and exhibited slightly improved Se and I content in wool. In conclusion, natural pasture provides adequate status in Se and I for the Merino ewes and their offspring without any additional beneficial effects of supplementation with Se and I or only Se