Effect of iron bioavailability on muscle fibre types and on quality and oxidative stability of grain-fed veal

The bioavailability of dietary iron can be reduced by using a chelator in the ration. In order to characterise the effects of supplementing veal calf rations with three doses of EDTA (0, 5 or 15 mg EDTA mg-1 Fe in the ration) for 8 or 18 wk, histochemical characteristics of the longissimus thoracis (LT) muscle and meat colour, composition, quality and stability were evaluated. Meat pH, colour, drip loss, cooking loss and shear forces were measured after a keeping period of 0, 7 and 14 d at 4°C, while lipid stability (thiobarbituric acid reactive substances) was measured on thawed ground meat stored for 1, 3 and 5 d at 4°C. EDTA treatments had no effect on dissectible tissue composition of the 9–11th rib section (P > 0.05) or on the chemical composition of the LT muscle (P > 0.05). EDTA dose had a quadratic effect (P < 0.05) on the proportion of slow-twitch, oxidative (SO) fibres and a negative, linear effect (P < 0.01) on the proportion of fast-twitch, oxidoglycolytic (FOG) fibres in the LT. The chelator was effective in enhancing paleness of veal, particularly with long-term administration of the highest dose (P < 0.05). This interaction, however, had a negative effect on shear force and also on oxidative stability of the meat during storage (P < 0.05).