Changes in the Fatty Acid Composition of M.longissimus dorsi of Lamb during Storage in a High-Oxygen Modified Atmosphere at Different Levels of Dietary Vitamin E Supplementation

摘要

The effect of vitamin E supplementation on fatty acid composition during storage of lamb meat packed in a high-oxygen modified atmosphere was studied.Lambs were fed with diets supplemented with four levels of vitamin E(0,250,500,and 1000 mg acetate-a-tocopherol/kg feed).Slices of M.longissimus dorsi were packed in a high-oxygen modified atmosphere(70% O2:30% CO2)and stored at 2 ± 1 deg C in the dark for 14,21,and 28 days.The nonsupplemented group(E0)showed an increase in saturated fatty acids(SFA)and monounsaturated fatty acids and a reduction in polyunsaturated fatty acids(PUFA)in total fatty acids.The proportion of SFA and PUFA was unchanged in the supplemented groups(E250,E500,and E1000).The supplementation with 250 mg acetate-a-tocopherol/kg feed prevented the oxidation of PUFA in the total lipids and in the polar lipids fraction,while 500 mg acetate-a-tocopherol/kg feed was necessary to prevent the oxidation of PUFA in free fatty acids.Supplementing vitamin E not only inhibited lipid oxidation but also maintained nutritional value [essential fatty acids,linoleic acid(C18:2n-6)and linolenic acid(C18:3n-3),and beneficial fatty acids,eicosapentaenoic acid(C20:5n-3)and docosahexaenoic acid(C22:6n-3)] throughout the storage period.