Öffentlicher Abendvortrag des Naturwissenschaftlichen Vereins +++ Referent: Prof. Dr. Thomas Vilgis (Max-Planck-Institut für Polymerforschung, Mainz)
Dieser Vortrag über natürliche Nanopartikel in Lebensmitteln findet im Rahmen einer Konferenz mit Studierenden und Professoren aus Belgien und Portugal statt und wird vom Deutschen Akademischen Austauschdienst (DAAD) gefördert. Aus diesem Grund wird der öffentliche Vortrag in Englisch sein. Der Referent ist jedoch Deutscher, sodass Fragen auch in deutscher Sprache gestellt werden können.
Taste, mouth feel, texture, and aroma perception of our daily food are definitely ruled by complicated interplays between polyelectrolytes, proteins, carbohydrates, fat, water, surfactants, ions, and aroma compounds. Their solubility, structure, function and elementary properties define many structural properties in all foods, which turn out to obey multiscale properties, i.e., their structure and function covers all scales, from nanometers up to macroscopic dimensions. Nanoparticles play often essential roles.
However, even natural food contains nanoparticles. A well-known example is (raw) cow milk. It contains fat particles with a relatively broad size distribution, but almost monodisperse protein micelles of diameters between 60 and 68 nanometers. These particles are able to form (fractal) particle gels under pH-changes or enzymatic reactions. Their nanostructure determines most of the texture and mouthfeel of yoghurts and fresh cheeses. Similar remarks apply to soybeans, which contain nanosized organelles as fat storage particles. The size of these spherically shaped oleosomes measures 360 nanometers diameter, as it was confirmed recently by small angle neutron scattering. Aqueous solutions of oleosomes form stable emulsions and colloidal suspensions, due to their charged, protein dominated surface. Moreover their size and interfacial behaviour enables many applications from fundamental soft matter physics to engineering. These particles can be used for food structuring, such as traditional foods as tofu (soy “cheese”) and yoba (soy skin), but also for novel products, such as soy (ice) cream. Moreover their applications range from functional foods, cosmetics, and drug release.