engleski

Impact of the Cationic Surfactant on the Self-Assembly of Sodium Caseinate

Impact of a cationic surfactant, dodecylammonium chloride (DDACl), on the supramolecular organization of sodium caseinate (SC) has been investigated by light scattering, zeta potential and rheological measurements as well as by microscopy (transmission electron and confocal laser scanning microscopy). In SC dilute solutions self-assembly proceeds through formation of spherical associates and their aggregation into elongated structures composed of connected spheres. DDACl interacts with SC via its hydrophilic and hydrophobic groups, inducing changes in SC supramolecular organization. These changes strongly depend on the surfactant aggregation states (monomeric or micellar) as well as concentration ratio of both components leading to formation of soluble and insoluble complexes of nano- to micro-dimensions. DDACl monomers interact with SC supramolecular entities in a different way compared to their micelles. Surfactant monomers form soluble complexes (similar to surfactant mixed micelles) at lower while insoluble gelatinous complexes at higher SC concentration. At surfactant micellar concentration soluble complexes with casein chains wrapped around surfactant micelles are formed. This study suggests that use of proper cationic surfactant concentration allow us to modify and control structural changes of SC supramolecular organization.

casein; cationic surfactant; self-assembling; complexation

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