Oxidation and antioxidant status: effects on shelf-life of meat from Limousine cattle fed with supplements of a-tocopherol

The purpose of this study was to evaluate the antioxidant status of meat from cattle fed diets supplemented with vitamin E (a-tocopherol acetate) during the finishing period and to evaluate the effect of this treatment on meat shelf-life. Twenty purebred Limousine calves reared in the same farm, were randomly selected, divided into control group (n = 10) and treated group (n = 10) and fed a total mixed ration: treated group received a supplementation of vitamin E (900 mg/kg of CMF) for a period of 150 days before slaughter.Meat quality was evaluated by the following analyses: pH, water holding capacity (drip loss), colour (L*, a*, b*, C*, H*), chemical forms of myoglobin, substances reactive to thiobarbituric acid (MDA) and enzymatic antioxidant activity (superoxide dismutase, catalase and glutation peroxidase). Dietary vitamin E supplementation had a positive effect on water holding capacity; in the control group a considerable increase in drip loss from the 2nd to 6th day of conservation was observed (2.83% vs 7.54%), while in the treated group during the same time period this increase appeared to be much more gradual and occurred to a lesser degree (2.31% vs 4.15%). Moreover, administration of vitamin E led to greater stability of colorimetric coordinates and reduced discoloration of the longissimus dorsi muscle during conservation as indicated by the redness a* (control: 23.85 and 23.87 vs 19.34 at 2h, 2 and 6 days, respectively; treated: 24.88, 23.91 and 24.01 at 2h, 2 days and 6 days, respectively) and in the Chroma* (control: 26.89 and 26.77 vs 21.90 at 2h, 2 days and 6 days, respectively; treated: 27.67, 26.57 and 26.77 at 2h, 2 and 6 days, respectively). Superoxide dismutase activity was significantly greater in the meat from cattle treated with vitamin E compared to that observed in the meat from controls (0.204 vs 0.167). The study showed that vitamin E supplementation in the finishing diets of calves caused only slight modifications in the antioxidant status of the meat; however, it positively influenced several qualitative characteristics which appeared to be more stable over time, thus extending the shelf-life of the meat.