Partitioning of ρ‐tocopherol in aqueous mixtures of TAG and isolated muscle membranes

Abstract

AbstractTo study the uptake of ρ‐tocopherol by aqueous suspensions of membranes isolated from chicken muscle and the partitioning of the antioxidant in mixtures of chicken TAG and membranes, ρ‐tocopherol was added to suspensions of these components and they were centrifuged. In an aqueous suspension of membranes only, the tocopherol uptake increased linearly with tocopherol concentration, at about 50% of the added ρ‐tocopherol at all concentrations. The incorporation of tocopherol into the membranes was independent of incubation temperature in the range of 0–37°C. Studies with aqueous mixtures of membranes and TAG suggested a very low exchange of tocopherol between the different lipid fractions upon mixing when the tocopherol resided initially in one lipid fraction. Adding ρ‐tocopherol in ethanol favored incorporation of the antioxidant into the membranes; little antioxidant was incorporated into the membranes when it was added to the suspensions in oil. The results suggest that partitioning of exogenous ρ‐tocopherol between TAG and membrane lipids in muscle foods may be controlled in part by proper selection of the solvent in which it is added.