Beef quality attributes as affected by increasing the intramuscular levels of vitamin E and omega-3 fatty acids

摘要

The objective of the present study was to investigate the effects of increasing beef omega-3 fatty acid content and the protective effect of vitamin £ antioxidant activity on meat quality characteristics. Eighty feedlot steers were fed 4 different diets (control, high vitamin £, 10% ground flaxseed or high vitamin E + 10% ground flaxseed) and meat quality characteristics were measured. While dietary treatments had no effect (P>0.05) on meat composition or tenderness values, the increase in oxidation products was lower (P=0.046) in meat from vitamin E supplemented steers and higher (P=0.006) in meat from flaxseed fed animals. The increase in a-tocopherol tissue levels (P<0.001) in meat from animals fed flaxseed and high vitamin E resulted in lower longissimus thoracis drip loss (P=0.013). As expected, ageing had a large effect on retail traits in both steaks and patties (P<0.001). While retail traits of steaks were not affected by the dietary treatments (P>0.05), ground beef from flaxseed fed steers had lower (P<0.05) retail scores, which were not corrected by higher levels of dietary vitamin E. Finally, although no effect was observed among treatments for sensory attributes in steaks, retail and sensory attributes were correlated with the n-3:a-tocopherol ratio (P>0.05). The results suggest the need to maintain a correct tissue balance between the recommended increase in n-3 fatty acids and the levels of endogenous antioxidants, such as vitamin E, in order to prevent negative effects on meat quality from a loss in oxidative stability.