Food grade liposome systems: Effect of solvent, homogenization types and storage conditions on oxidative and physical stability

Liposomes are the form of phospholipids which could inherently form spherical capsules in aqueous solution by energy. In this study, egg and soy lecithin were used to form liposomes by probe type ultrasonication and high pressure homogenization (microfluidization-MF) methods. To detect physical and chemical changes during storage of liposomes; particle size, zeta potential, transmission electron microscopy, optical microscopy and hydroperoxide formation experiments were conducted for one month. Microfluidization was found to be more efficient than ultrasonication in particle size reduction. When compared with egg lecithin, soy lecithin was found to oxidize less at refrigeration temperature while egg lecithin was better at room temperature, forming less hydroperoxide. Increase in unbound water resulted an increase in hydroperoxide formation with ultrasonication. Disruption of the spherical unity of the liposomes detected by particle size measurements was proposed to increase hydroperoxide formation due to exposure of hydrophobic compartments to the environment while presence of dihydrogen phosphate drastically decreased it. (C) 2016 Elsevier B.V. All rights reserved.