The Effect of Dietary Vitamin E Source and Dose on Lamb Meat Colour Stability under Retail Conditions

The effect of natural (NE) and synthetic vitamin E supplementation (SE) on lamb meat packed under modified atmospheres (MAP) for 14 days was studied. Three hundred and sixty Rasa Aragonesa lambs were offered nine dietary treatments (0, NE125, NE250, NE500, NE1000, SE250, SE500, SE1000 and SE2000). Lambs had ad libitum access to the experimental compound feed and wheat straw, for 14 days (pre-slaughter). After slaughter (24h), twelve left longissimus thoracis et lumborum (LTL) muscles per treatment group were extracted, sliced and MAP packed. Lamb chops were accessed for colour (a* and L*) and m-protein forms (MMb and DMb) at day 1, 7, 9, 12 and 14 of display under retail conditions. Increased supplementation of vitamin E led to a reduction in L*, DMb degradation and consequently, MMb. Redness (a*) of the chops was improved by vitamin E supplementation. Both sources of vitamin E were effective in protecting meat colour over the 14 days of display. However, similar effects in colour preservation were obtained at lower dosages of natural vitamin E. In general, supplementation of lamb diets with vitamin E is an effective measure to delay colour deterioration of MAP lamb, under retail conditions for periods longer than 7 days.