Emulsifiers from olive stones

Emulsifiers have been extracted from the alcohol-insoluble solids of olive (Olea europaea L.) stones. The extracts containing proteins and carbohydrates were characterized by dynamic light scattering, zeta potential mea-surements, Fourier transform infrared spectroscopy (FT-IR), Gas chromatography coupled with mass spectros-copy GC-MS, and size exclusion chromatography (SEC). The FT-IR and SEC data agree that the extracts have two macromolecular structural components: a polysaccharidic and a proteinic population. Experiments have been conducted as to evaluate the extracts' ability to emulsify oil-in-water emulsions, using confocal laser scanning microscopy for the examination of the microstructure, and static light scattering for the determination of droplets/flocs size distributions. The extracts are adequate emulsifiers for neutral model emulsions, providing stability against coalescence for 14 days. The interfacial characteristics of the extracts' components (interfacial composition/topology and dynamic interfacial tension) have been examined as to complement the composition, emulsification and emulsion stability data. This work concludes that olive stones, the main by-products of olive processing, have the potential to act as sources of high added-value emulsifiers.