About myself

I completed both my bachelor and master studies at the University of Hohenheim. After completing the bachelor in Food Science and Biotechnology, I proceeded with the international master in Food Science and Engineering. During my studies, I did an internship at FrieslandCampina (Heilbronn) in the division SHE/QA (safety, health, environment and quality assurance). Afterwards, I deepened my knowledge about emulsions during a research internship in the laboratories of Prof. Alejandro G. Marangoni at the University of Guelph, Canada. My research focused on monitoring the crystallization and polymorphic transformation of a palm-kernel based emulsion using ultrasound.

I finished my master degree with the thesis on the “Investigation of the application potentials of Raman spectroscopy for the early detection of defects in dairy products”.

February 2018, I started my doctoral studies as part of my work as a research assistant in the research area of melt emulsions.

Research focus

My research focuses on the phase transitions of O/W melt emulsions. The production of these emulsions follows a two-step process: in the first step, the disperse phase is emulsified in a mechanical emulsification process at temperatures above its melting point/range. In the second step, cooling of the emulsion results in a fine dispersed (partially) crystalline suspension. I mainly focus on the crystallisation of these emulsion droplets. Instability mechanisms like aggregation or (partial) coalescence occur in food and cosmetics mainly due to the physical state of the emulsion droplets, which can exist as supercooled liquid, amorphous or crystalline droplets. Additionally, insufficient interface stabilization can play a role. Temperature fluctuations during storage or transport can cause recrystallization, which means changes in the crystal structure. The production of sustainable products with a shelf life of several months, these aforementioned instability phenomena have to be understood and thus reduced. Therefore I investigate e.g. the influence of production parameters or formulation on the interface stabilization and droplet crystallization.

Methods

I use various emulsification devices like a tooth rim dispersing machine and a high-pressure homogenizer for the production of these crystalline suspensions. Thus, it is possible to obtain solid lipid particles in the range from a few nanometers to a few micrometers. To characterize the crystallization in emulsions, I use a Nikon polarizing microscope equipped with a Linkam heating/cooling stage. This allows the investigation of crystallization processes in a temperature range from -196 °C to +420 °C with cooling/heating rates from 0.01 to 50 K/min. The polarization equipment enables the differentiation between crystalline structures and liquid droplets. Additionally, an optical shearing cell allows us to additionally examine the influence of shearing/oscillating forces on the crystallization and stability of emulsions. Further analytical methods used in my research are differential scanning calorimetry, laser diffraction analysis and tentiometry. Solid fat content and different crystalline structures/polymorphs are investigated by means of NMR spectroscopy and powder X-Ray diffraction.