Effect of vitamin E supplementation and diet on fatty acid composition and on meat colour and lipid oxidation of lamb leg steaks displayed in modified atmosphere packs

To determine the effect of basal diet, concentrates (C) or silage plus concentrates (S), on vitamin E deposition and meat quality, groups of 8 lambs were allocated to one of five concentrate diets supplemented with all-rac-α-tocopheryl acetate to contain 30 (C30), 60 (C60), 120 (C120), 250 (C250) and 500 (C500) mg/kg dry matter. Two other groups were fed grass silage and 400g/day concentrate with the equivalent of 60 (S60) or 500 (S500) mg α-tocopheryl acetate/kg dry matter. Within diet, vitamin E level did not affect growth performance or carcass characteristics. Basal diet did not affect final live weight, conformation and fatness scores. M. semimembranosus from S lambs contained more α-tocopherol than that of C lambs on the same intake: S60 3.2 μg/g, C60 1.1 μg/g, S500 5.1 μg/g, C500 3.75 μg/g and by day 6 in MAP (75%O2/25%CO2) chroma and a* were below acceptable levels in C30 lambs. TBARS were higher in C30 and C60 muscle than in other treatments (P