Liposomes are nanocapsules successfully applied in pharmacy and medicine. Their usage in the food industry could be increased by the development of alternative, cost-efficient lecithin materials. This work is a continuation of the previous two papers describing five different extractions of egg yolk lecithins and the preassessment of their usefulness for liposome formation. Physicochemical properties of extracts differed due to distinct composition. The aim of this research was to further characterise the extracts-based liposomes, especially in terms of nanomechanical properties and structural diversity. Five previously described extracts were used for liposomes preparation employing Bangham technique. Vesicles were analysed with the use of dynamic light scattering, flow cytometry, and atomic force microscopy. The results were tested for correlation with the composition of the extracts. It was proved that the chemical composition of the shell-forming material determined the size, structure, stability, and mechanical properties of the vesicles. The observed effects were found to result not only from differences in the content of major components, i.e. phospholipids, acylglycerols, and cholesterol, but also in the relative proportions. Minor constituents, i.e. tocopherols and carotenoids, were also found to be of significance. Strong correlations between size and Zeta potential of the vesicles with the content of carotenoids were determined.

Liposomes are nanocarriers widely used in pharmaceutical industry. Due to intravenous route of administration, they have to be produced from phospholipids of very fine purity. On the other hand, there is increasing interest in nanoencapsulation of labile, bioactive substances for manufacturing of health promoting food. Unfortunately, high-price pure phospholipids are prohibitive for food applications. The use of raw material obtained by simple extraction procedure instead of highly purified phospholipids could be an attractive alternative for food industry.

Egg yolk, due to its emulsifying properties has a longterm tradition in food technology applications. Additionally, egg yolk extracts obtained through simple procedures were proved to be an attractive alternative to highly purified phospholipids. The aim of this work was to analyse the interfacial behaviour of previously described extracts in relation to liposomes preparation. The extracts underwent analysis of surface properties: the π-A isotherm, dilatational and stress rheology experiments as well as surface potential analysis with the use of Langmuir trough. It was proved that EA, MA and HE films were characterized by the highest collapse pressure during compression, but revealed relatively large hysteresis, suggesting irreversibility. CE extract showed minor hysteresis and high reversibility of orientation changes. The most important factor determining the elastic response on area deformation is the content of phospholipids. The lysophosphatidylcholine/phospholipids ratio is also the important factor. The balance between polar and non-polar fraction of lipids and high content of phopsholipds fraction in the film are conducive for solid-like response on shear stress whereas the presence of lysophosphatidylethanolamine induce fluid-like behaviour of this complex film. Minor film constituents significantly affect properties of the film too. MA and EA extracts revealed the highest similarity. CE and HE extracts also showed significant similarity to each other, whereas H extract differed from each.