Thesis subject

Micro delivery systems made of food polymers

Food Manufacturers and the pharmaceutic industry have become more and more interested in protecting compounds from outside influences, both during storage and after ingestion. During their lifetime, these compounds encounter a broad range of environments with varying pH, ionic strength, enzymes and humidity. It is therefore important to develop new structures for the protection and delivery of unstable or nutritionally valuable compounds.

We have developed a new delivery system for hydrophobic compounds. These microcapsules are made by a double emulsification step. Oil droplets with the compound to be delivered and protected are dispersed in an alginate or whey protein solution. This emulsion is then emulsified in an oil phase, which creates a double emulsion. The size of the microcapsules can be tuned by this second emulsification step, and can be kept under 25┬Ám to prevent negative sensorial aspects. After gelation of the interior of the capsule, the particles may be extracted from the oil phase by a centrifugation step.

Once removed from the oil phase, both alginate and protein microcapsules are charged. This gives the opportunity to apply additional layers on the capsule via the layer-by-layer method. With these extra layers, the release and stability of the compounds in the inner oil phase can be tuned further by varying the number of layers.

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Research topics

  • Release studies of active  ingredients of different types of microcapsules
  • Developing new capsules from different protein or polysaccharide sources


  • Electron and Confocal Microscopy (SEM, CLSM)
  • Spectroscopy and chromatography (release studies)
  • Particle sizing (light scattering)