K.K. Scheller

Dietary vitamin E supplementation and discoloration of pork bone and muscle following modified atmosphere packaging

The effects of modified atmosphere (80% O(2): 20% CO(2)) and illumination on the discoloration rate of pork bone (lumbar vertebrae) and muscle (longissimus lumborum), and on muscle lipid stability were studied in vitamin E-supplemented and unsupplemented pigs. Bone-in pork chops were placed in 80% O(2): 20% CO(2) at 0 °C and stored for 5 days in the dark. The chops were then displayed under (a) fluorescent light in air or modified atmosphere or (b) in air with or without illumination. Lipid oxidation was increased by the modified atmosphere packaging but this detrimental effect was offset by vitamin E supplementation. Higher supplementation levels (198 and 207mg/kg) improved bone color stability regardless of the packaging atmosphere or the lighting conditions. Although vitamin E supplementation improved muscle color stability during display in air or modified atmosphere, the benefit of supplementation on muscle color was detectable only for illuminated storage.

Effect of dietary vitamin E on pigment and lipid stability of frozen beef: A kinetic analysis.

The effect of vitamin E supplementation on pigment and lipid stability was evaluated with beef wrapped in high or low oxygen permeability films and stored in the dark or under constant illumination at -20°C. Dietary vitamin E supplementation improved pigment and lipid stability in both cases. Illumination increased metmyoglobin accumulation but did not affect lipid oxidation rate in both control and supplemented beef. A predisplay dark storage period of 30 days delayed metmyoglobin accumulation during subsequent display. Kinetic analysis showed that vitamin E supplementation stabilized the oxymyoglobin complex by enhancing the deoxymyoglobin oxygenation rate and by decreasing oxymyoglobin autoxidation rate.

Atmosphere and blooming time affect color and lipid stability of frozen beef from steers supplemented with Vitamin E

The influence of blooming time (1, 6 or 48 h) and atmosphere (air or 100% oxygen) on color and lipid stability of frozen Longissimus lumborum (LL) from control and vitamin E supplemented steers was studied. Samples were stored at -20°C with or without illumination. Blooming control LL for 48 h in air followed by dark storage increased discoloration. Supplementation and blooming in oxygen, separately or combined, increased color display life. Illumination increased discoloration. Supplementation coupled with blooming for 6 or 48 h in 100% oxygen provided the highest color stability in both dark and illuminated storage. Color display lives for supplemented LL bloomed for 6 and 48 h in oxygen were 182 and 212 days for dark storage, and 21 and 73 days for illuminated display. Supplementation decreased lipid oxidation in illuminated LL, but blooming for 48 h in oxygen minimized this effect.