Oil in water emulsions (o/w) formulated with sunflower lecithins: Vesicle formation and stability

PAN, L., TOMÁS, M.C., AÑÓN, M.C.

JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY (JAOCS)

Año: 2004 vol. 81 p. 241 - 244

0003-021X

ABSTRACT: Oil-in-water emulsions (30:70, vol/vol) were formulatedwith sunflower lecithin to characterize the destabilizationprocesses and the vesicles formed. Dispersions containinglevels of 0.1% lecithin were more stable against coalescence thanthe control system. When the lecithin concentration was increasedto 0.5%, the presence of spherical structures, such asvesicles, was recorded that occluded the emulsion inside. Vesiclesunderwent a creaming process, and a narrow coalescence zonewas detected in the upper layers of the samples. As the lecithinconcentration was increased, more vesicles were formed, representingas much as 80% of the system volume. A reduction in theaverage size of vesicles was observed at high lecithin concentrations(2.5 and 5.0%). The vesicle size distribution changed as afunction of lecithin concentration, decreasing the ratio of large tosmall particles in the same way. Coalescence took place in zoneswhere large-volume vesicles were in contact in the upper portionof the tube sample. The results obtained suggest that sunflowerlecithins present interesting emulsifying properties that may proveuseful in food technology.large volume of sunflower oil produced in Argentina representsa potential source of lecithin. Thus, basic informationon the utilization of this commodity is required. This studyreports the stability of O/W emulsions: The aims of the presentwork were to study O/W emulsions formulated with sunflowerlecithin and to characterize the formation of vesiclesand their destabilization.