Regarding the lecithin systems, the kinetic stability was very low, mainly in water–hexadecane systems. The microscopic images of the systems with hexadecane showed the formation of an emulsion with very large and polydisperse water droplets, which explains the fast emulsion destabilization. The reason for the big-sized droplets was the slow migration of lecithin molecules to the interface, which hindered the droplet breakup. The low mobility of the emulsifier was supported by the short decrease of the interfacial tension of the water–pure oil interface (22 and 40 mN/m for water–soybean oil and water–hexadecane, respectively) to the interface with lecithin (9.2 mN/m for soybean oil and 24.1 mN/m for hexadecane) (Fig. 4). The slow mobility of lecithin molecules is probably due to the presence of charged groups in the hydrophilic moiety, which have low mobility in the hydrophobic medium. The mobility is even lower in hexadecane, which is more hydrophobic than soybean oil. Another reason for the low stability of lecithin emulsions is the fact that the lecithin tested in this study did not have its phospholipids concentration modified. As it is already known, PC enriched lecithin is better for oil-in-water emulsions, while lecithin with higher concentration of PE and PI are more appropriated to produce water-in-oil emulsions (Wu & Wang, 2003). Furthermore, the aqueous phase separation observed in emulsions with lecithin at high water content (60:40 W:O ratio) (Table 1) suggests the weak interaction of the hydrophilic part of the emulsifier with water molecules. Lecithin hydrophilic moiety has only one hydroxyl and ionic groups (Fig. 1), which cannot form a structured interface as suggested in PGPR and Span 80 emulsions.