Modified phosphatidylcholine with different alkyl chain length and covalently attached caffeic acid affects the physical and oxidative stability of omega-3 delivery 70% oil-in-water emulsions

This study investigated the effects of modified phosphatidylcholine (PC) with different alkyl chain lengths (PCC14 and PCC16) and covalently attached caffeic acid on the physical and oxidative stability of 70% fish oil-in-water emulsions. High fat emulsions were produced using different amounts of modified PCs in combination with sodium caseinate and soy-PC. Results showed that the physical stability of the emulsions was improved with increasing concentrations of modified PCs, due to their high surface activity. Emulsion stabilized with PCC14 led to smaller droplets and higher viscosity, whereas PCC16 had higher protein surface load, which may result in a thicker interfacial layer. Modified PCs enhanced the oxidative stability of the emulsions due to the attachment of caffeic acid to the glycerol backbone of PC, which brings the antioxidant in the vicinity of oil-water interface. PCC16 led to less formation of primary and secondary oxidation products compared to PC₁4 at their equivalent concentrations.