Cysteines in β-lactoglobulin affects its interfacial adsorption and protein film stabilization.

Hypothesis: Disulfide bonds in proteins are strong chemical bonds forming the secondary and tertiary structure like in the dairy protein β-lactoglobulin. We hypothesize that the partial or complete removal of disulfide bonds affects the structural rearrangement of proteins caused by intra- and intermolecular interactions that in turn define the interfacial activity of proteins at oil/water interfaces. The experimental and numerical investigations contribute to the mechanistic understanding of the structure-function relationship, especially for the interfacial adsorption behavior of proteins.

Characterization of β-lactoglobulin adsorption on silica membrane pore surfaces and its impact on membrane emulsification processes.

Protein adsorption plays a key role in membrane fouling in liquid processing, but the specific underlying molecular mechanisms of β-lactoglobulin adsorption on ceramic silica surfaces in premix membrane emulsification have not been investigated yet. In this study, we aimed to elucidate the β-lactoglobulin adsorption and its effect on the premix membrane emulsification of β-lactoglobulin-stabilized oil-in-water emulsions. In particular, the conformation, molecular interactions, layer thickness, surface energy of the adsorbed β-lactoglobulin and resulting droplet size distribution are investigated in relation to the solvent properties (aggregation state of β-lactoglobulin) and the treatment of the silica surface (hydrophilization).

Protein conformational changes at the oil/water-interface induced by premix membrane emulsification.

We present combined experimental and modelling evidence that β-lactoglobulin proteins employed as stabilizers of oil/water emulsions undergo minor but significant conformational changes during premix membrane emulsification processes. Circular Dichroism spectroscopy and Molecular Dynamics simulations reveal that the native protein structure is preserved as a metastable state after adsorption at stress-free oil/water interfaces. However, the shear stress applied to the oil droplets during their fragmentation in narrow membrane pores causes a transition into a more stable, partially unfolded interfacial state.

Structure and adsorption behavior of high hydrostatic pressure-treated β-lactoglobulin.

Hypothesis: High hydrostatic pressure treatment causes structural changes in interfacial-active β-lactoglobulin (β-lg). We hypothesized that the pressure-induced structural changes affect the intra- and intermolecular interactions which determine the interfacial activity of β-lg. The conducted experimental and numerical investigations could contribute to the mechanistic understanding of the adsorption behavior of proteins in food-related emulsions.

Engineering considerations on extrusion-based bioprinting: interactions of material behavior, mechanical forces and cells in the printing needle.

Systematic analysis of the extrusion process in 3D bioprinting is mandatory for process optimization concerning production speed, shape fidelity of the 3D construct and cell viability. In this study, we applied numerical and analytical modeling to describe the fluid flow inside the printing head based on a Herschel-Bulkley model. The presented analytical calculation method nicely reproduces the results of Computational Fluid Dynamics simulation concerning pressure drop over the printing head and maximal shear parameters at the outlet.

Chemistry of iron nitrate-based precursor solutions for spray-flame synthesis.

Understanding the chemistry of iron-based metal-organic precursor solutions for spray-flame synthesis is a key step to developing inexpensive and large scale applications for gas-phase synthesized, nano-sized iron oxide particles. Owing to the large variety of available organic solvents and iron compounds, the choice of a suitable precursor-solvent pair is challenging. Systematic investigations of the precursor chemistry of iron-based systems are currently not available.

Conformational state and charge determine the interfacial stabilization process of beta-lactoglobulin at preoccupied interfaces.

Amphiphilic properties enable proteins like β-lactoglobulin to stabilize oil/water-interfaces and provide stability in food-related emulsions. During emulsification, the protein undergoes three stages: (I) migration through bulk phase, (II) adsorption, and (III) interfacial rearrangement at the oil/water-interface - the kinetics of which require further research. Therefore, the aim of our study was the analytical and computational investigation of stage (I) and (II) as a function of the interfacial preoccupation, conformational state and charge of β-lactoglobulin.

Screening Precursor-Solvent Combinations for LiTiO Energy Storage Material Using Flame Spray Pyrolysis.

The development and industrial application of advanced lithium based energy-storage materials are directly related to the innovative production techniques and the usage of inexpensive precursor materials. Flame spray pyrolysis (FSP) is a promising technique that overcomes the challenges in the production processes such as scalability, process control, material versatility, and cost. In the present study, phase pure anode material LiTiO (LTO) was designed using FSP via extensive systematic screening of lithium and titanium precursors dissolved in five different organic solvents.

Dynamic forces on agglomerated particles caused by high-intensity ultrasound.

In this paper the acoustic forces on particles and agglomerates caused by high-intensity ultrasound in gaseous atmosphere are derived by means of computational fluid dynamics (CFD). Sound induced forces cause an oscillating stress scenario where the primary particles of an agglomerate are alternatingly pressed together and torn apart with the frequency of the applied wave. A comparison of the calculated acoustic forces with respect to the inter particle adhesion forces from Van-der-Waals and liquid bridge interactions reveals that the separation forces may reach the same order of magnitude for 80 μm sized SiO2-particles.