Soy PC liposomes as CLA carriers for food applications: Preparation and physicochemical characterization

Soy phosphatidylcholine (PC) liposomes added with conjugated linoleic acid isomers, (CLA, 9c, 11t, and 10t, 12c) at two PC/CLA ratios, 2:0.4 and 2:1, were prepared by ethanolic injection, and followed during 30 days of storage. These systems were investigated in encapsulation efficiency and fatty acid composition by gas chromatography, size by dynamic light scattering, morphology by TEM images, and membrane fluidity by electron paramagnetic resonance (EPR). Both type of formulations showed highly significant stability and protective effect on CLA isomers with encapsulation efficiencies over 80% during storage. Liposome sizes increased at increasing CLA content. TEM showed evidence of oligolamellar vesicles formation. Regarding membrane fluidity, two behaviors were distinguished in the bilayer: CLA at both formulations disordered the outer membrane zone increasing its fluidity, but the formulation with higher CLA content caused a decreased fluidity near the center of the membrane. The method is safe and easily scalable, and formulations are suitable for future applications in food industry.