IMPROVEMENT OF THE QUALITY OF BEEF BY DIE TARY VITAMIN-E SUPPLEMENTATION IN THE FINISHING PERIOD OF YOUNG BULLS - 2 - COLOR, FAT STABILITY AND DRIP LOSS

Dietary vitamin E supplementation during the fattening period has a po sitive effect on meat quality, as the colour of the meat remains more stable, fat oxidation is delayed, and a positive effect on water reten tion has also been shown. The results with beef so far available are m ainly based on data from steers intensively fattened on concentrate di ets, while no information on bulls fattened predominately on corn sila ge is available. The effects of vitamin E levels greatly exceeding he nutritional requirements (600 to 2000 mg per day, for 80 or 120 days) in the finishing period of bulls on performance, carcass and meat qual ity were investigated. The second report presented here shows the resu lts concerning colour stability, fat stability and drip loss in the mu scles M. longissimus dorsi (MLD) and M. semitendinosus (MST), which we re taken from the carcass 48 h post slaughter and aged 10 days at 2 de grees C. Doses of vitamin E over the requirements in the finishing per iod of young bulls have positive effects on colour stability, delayed fat oxidation and tended to reduce drip loss. The differences in colou r stability were very small until day J of storage, after this time th ey were apparent in the intensity of redness (a), chroma, hue angle a nd met- and oximyoglobin contents. Both groups receiving vitamin E sup plementation for the longer time (120 days vs 80 days) showed a more p ronounced effect on colour stability, while the rate of supplementatio n had a slightly less pronounced effect. The ability of fat to resist oxidation was clearly affected by vitamin E addition, and the positive effect was enhanced with higher levels of supplementation. There was a tendency for a reduction in drip loss in the supplemented groups.