The effects of dietary vitamin E upon colour, bacteriology and case life of beef was examined following extended storage of longissimus thoracis (LT) muscle in vacuum or in anoxic atmospheres containing 100% CO2 The diets of treated steers were supplemented with 1000 IU of vitamin E animal−1 d−1 for 100 d. Animals were slaughtered in a research abattoir and after 24 h of postmortem aging the LT muscles were removed and assignedto a packaging treatment for storage for up to 11 wk at 2 °C. Rib-eye steaks were cut and displayed under simulated retail conditions to give a surface temperature of 6 °C after storage intervals of 0, 3, 6, 9 and 11 wk. Feeding treatment had no effect (P > 0.05) upon standard carcass and muscle quality traits or bacterial growth but increased carcass α-tocopherol levels from 2.89 µg g−1 in control animals to 5.18 µg g−1 in carcasses supplemented with vitamin E (P < 0.0001). The α-tocopherol concentration in LT muscles was unaffected (P > 0.05) by storage time for up to 11 wk in either packaging treatment. Dietary vitamin E increased a* values and reduced metmyoglobin accumulation after LT storage for up to 11 wk irrespective of package atmosphere. However, dietary vitamin E had no significant effect (P > 0.05) on the colour case life of steaks derived from the LT muscle after vacuum storage for 3 to 11 wk. Contrarily, vitamin E acted synergistically with the CO2 packaging treatment to produce an increase in colour case life from 2.7 (control) to 5.4 d (vitamin E) after 6 wk of LT storage and from 2.4 (control) to 4.0 d (vitamin E) after 9 wk of LT storage (P < 0.0001). In combination with anoxic, CO2 packaging, dietary vitamin E may play a role in assuring beef colour stability following extended periods of storage necessary for fresh beef export. Key words: Vitamin E, packaging, beef storage
Effects of dietary vitamin E on growth performance, body composition, antioxidant capacity, and some immune responses in Caspian trout (Salmo caspius)
