The effects of dietary α-tocopheryl acetate supplementation and modified atmosphere packaging (MAP) on the quality of lamb patties.

The effects of dietary α-tocopheryl acetate supplementation and/or packaging on the quality of lamb patties were investigated. Ewes (n=12) were selected and scanned to assess pregnancy. They were divided into two groups (n=6). The control group was fed a non-supplemented diet of 20 mg α-tocopheryl acetate/kg feed/day for 9 weeks ante-parturition and 3 weeks post-parturition. The lambs were weaned at 3 weeks and fed either the non-supplemented or supplemented diet for 10 weeks prior to slaughter. The M. longissimus dorsi from each carcass from each dietary group was stored at -20°C for 7 months. Patties were formed from supplemented or control minced m. longissimus dorsi and held in either modified atmosphere packs (MAP) under atmospheres of 70:30, 80:20 or 90:10 CO(2):O(2), under vacuum or in overwrapped trays. All packs were held under refrigerated (4°C, 616 lux) display for a period of 10 days. Patties were assessed for oxidative and colour stability on days 0, 2, 4, 6, 8 and 10. With each type of pack, dietary α-tocopheryl acetate supplementation significantly increased oxidative and colour stability compared to control patties. As oxygen concentrations increased in MAP packs, colour stability was enhanced but the rate of lipid oxidation increased. Vacuum packaged patties had significantly (P<0.05) higher Hunter 'a' values, lower proportions of metmyoglobin and lower TBARS numbers than those held under all other forms of packaging. Aerobically packaged patties had lower Hunter 'a' values, higher proportions of metmyoglobin and lower TBARS numbers compared to MAP patties.