Effect of dietary supplementation with vitamin E on characteristics of vacuum-packed lamb

Abstract

The effect of dietary vitamin E supplementation on lamb during vacuum-packed storage was studied. Thirty-six weaned male Manchego breed lambs were offered four dietary treatments (20, 270, 520 and 1020 mg vitamin E kg -1 feed). Lambs were fed the vitamin E-supplemented diet from 13 until 26 kg live weight. Pieces of M. longissimus dorsi were stored under vacuum at 2 ± 1°C in the dark and meat quality was assessed after 5, 14 and 28 days of storage. Dietary supplementation significantly increased the α-tocopherol concentration in the muscle (P < 0.001). Initially, lipid oxidation, meat colour and bacterial load were similar in all groups. In meat of non-supplemented lambs the thiobarbituric acid reactive substance value increased throughout storage, whereas in meat of supplemented lambs it did not increase. Meat pigments and discolouration proportion were significantly affected by storage time (P < 0.001). The bacterial load was low initially, but after 28 days of storage it was close to 7 log10 colony-forming units (cfu) cm-2 and Enterobacteriaceae surpassed the limit of acceptability of 2.5 log10 cfu cm-2, making the lamb unsuitable for human consumption. Meat of supplemented lambs displayed less lipid oxidation than that of their non-supplemented counterparts, while meat colour and bacterial load were not affected by supplementation. © 2007 Society of Chemical Industry.