Dietary oils with added tocopherols: effects on egg or tissue tocopherols, fatty acids, and oxidative stability

Abstract

The effect of dietary oils [menhaden (MO), flax (FL), palm (PO), and sunflower oils (SF)] with added tocopherols on the tocopherol deposition, fatty acid composition, and thiobarbituric acid (TBA) values of egg or tissues (liver, adipose tissue, white meat, and dark meat) were examined. Addition of tocopherols increased (P < 0.05) the total egg or tissue tocopherol content. The enhancement of total tocopherols in the different tissues in the order of magnitude were egg yolk > liver > adipose tissue > dark meat > white meat. Dark meat contained higher (P < 0.05) total tocopherols than white meat. Dietary MO or FL resulted in a significant (P < 0.05) incorporation of C20:5 n-3 and c22:6 n-3 with a concomitant reduction in C20:4 n-6 in liver, egg, white meat and dark meat. Dietary SF resulted in a significant (P < 0.05) incorporation of C18:2 n-6 and C20:4 n-6 in all the tissues. Addition of PO did not result in any change in the yolk saturated fatty acid content. The content of monounsaturated fatty acids were greater (P < 0.05) in all the tissues from PO diets than in diets with other oils. Dietary tocopherols resulted in a significant increase (P < 0.05) in the content of C20:5 n-3 and C22:6 n-3 in the yolk, adipose tissue, and white meat from birds fed MO + T diets. Inclusion of tocopherols resulted in a significant (P < 0.05) reduction in TBA values in eggs, in liver for MO and FL diets, and in dark and white meat for the MO diet. Tocopherol supplementation did not result in any change in TBA values in the PO diet.