Emulsions are widely applied systems in the food sector. Usually, they are composed of an oil phase like triacylglycerides, a water phase and interfacial active components like proteins and low molecular weight emulsifiers.
The interfacial active components play a tremendous role for the micro- and macrostructure of emulsions, since proteins and low molecular weight emulsifiers stabilize the oil/water interface and guide the structure in the different length scales.
The macrostructure is mainly identified with the oil droplet size and dispersion, which is linked to the kinetics of interfacial stabilization during emulsification, and to the preservation of interfacial stabilization during storage of emulsions. The latter, in turn, is linked to the microstructure. The microstructure is identified with the characteristics of the interfacial film. These characteristics are: the interfacial tension, the interfacial arrangement of interfacial active components, the interfacial viscoelasticity affected by molecular folding of proteins and by interplay of interfacial active components like electrostatic and hydrophobic interactions. The microstructural characteristics strongly depend on the pH value of the water phase, the concentration, and the molecular structure of interfacial active components including factors like the isoelectric point of proteins. So far, the concepts of micro- and macrostructure of food emulsions are not systemized and combined for plant and animal derived protein sources.
Therefore, this postdoc position will investigate both micro- and macrostructural characteristics of emulsion systems via SLS, SANS, SAXS and NSE. The results are leading to an improved comprehension of the concepts of micro- and macrostructure of food emulsions, which will also guide to an improved understanding of fermented emulsion systems like yoghurt.
Dr. Jitae Park
Dr. Theresia Heiden-Hecht