30C-28 |
Effect of the use of solvents with different dielectric constants to add delta-tocopherol into chicken leg muscle: antioxidant partitioning between polar and neutral lipids |
M. A. DAVILA, Food Science, University of Massachusetts at Amherst, CCS 81242, PO BOX 025323, Miami, FL 33102-5323 and H. O. Hultin, Food Science, Marine Station, UMass, POB 7128 Lanesville Station, Gloucester, MA 01930. The properties of the solvents used to incorporate antioxidant into muscle tissues can prompt an antioxidant to partition into a specific lipid phase. This may improve the antioxidant activity and reduce deterioration caused by the oxidation of muscle lipids. The objective was to test the ability of three solvents to increase the partitioning of delta-tocopherol into the polar lipid phase, considered to be most susceptible to oxidation. Membrane polar lipids were prepared by differential centrifugation. Lipid phosphorus, protein, total lipids and delta-tocopherol contents were determined in the membrane fraction. Neutral lipids were physically obtained after one centrifugation at 30 °C. The delta-tocopherol content was determined by HPLC in the membrane fraction after extraction with a mixture of chloroform-methanol (1:1), and in the neutral lipids after resuspending an aliquot of the extracted oil in chloroform. A small volume of delta-tocopherol dissolved in ethanol and in propylene glycol was added to chicken leg muscle before and after adjusting the total lipid content of the muscle to 8-10 % with chicken oil. Additionally, delta-tocopherol was added directly to the oil used to adjust the total lipid content. The delta-tocopherol contents determined in the membrane and in the neutral lipid fractions were affected by the order of addition of the antioxidant and by the solvent used. The highest delta-tocopherol concentration in the membrane fraction was obtained when adding the antioxidant in ethanol before the adjustment of the total lipid content and the lowest when adding the antioxidant directly into the chicken oil. The highest delta-tocopherol concentration in the neutral lipids was obtained when the antioxidant was directly dissolved in chicken oil and the lowest when added in propylene glycol. The use of different solvents greatly affected the delta-tocopherol partitioning between polar and neutral lipids of chicken leg muscle.
Session 30C, Muscle Foods: Tenderness, Quality, Processing, Marination, Oxidation, and Shelf-Life
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