Controlled structuring of dispersed multiphase food systems
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The dispersed systems, such as emulsions and suspensions, are encountered in a large variety of applications areas, such as food, cosmetics, pharmaceutics and polymers. In order to obtain the desired properties of an emulsion in the dispersing process, the droplet size distribution has to be monitored and controlled. By combining droplet generation, deformation and fixation (emulsion-suspension transition) in one experimental set-up, equally shaped particles were produced in order to manipulate the microstructure of dispersions. In a first step, a co-flowing liquid-liquid emulsification process aiming to generate monodispersed droplets[1–2] was studied. With such droplets at hand, deformation of each individual droplet can be achieved in the second step when the flow field of the downstream apparatus is known. Using gelling biopolymeric material as dispersed phase it is further possible to “freeze” and conserve the non-equilibrium shapes of such deformed droplet. As a consequence, suspensions of gelled emulsion droplets of various shape and shape functionality were obtained[3–5]. These new shapes, such as sphere, fibrils and “hooky” bodies, provide an advanced tool to control and manipulate the rheological properties and product performance of dispersed systems beside the well-known influence of the volume fraction of the dispersed particles[4, 6–8].
Key wordsemulsions suspensions biopolymers gelation co-flow emulsification
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