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The present study investigates the effect of oil type on the formation, morphology and mechanical properties of phytosterol-based organogels. The formation of organogels can be satisfactorily predicted with a criterion based on Hansen Solubility Parameters (HSPs), provided that the sterol and sterol ester in these systems assemble as tubules. When structures other than tubules are formed, the predictability of the HSP-based criterion becomes void. In cases where organogelling occurred, the morphology and mechanical properties of the tubular network of the gels and water-in-oil emulsions were investigated. The findings revealed that the structure of the tubular network formed in oils with different compositions, could be grouped based on the dielectric constants of the oils. Curly and bundled tubules which formed networks, were observed in gels prepared with low dielectric constant oils (i.e. decane and limonene). For oils with a moderate dielectric constant (i.e. castor oil and sunflower oil), the tubules became less curly and straighter. Upon increasing the dielectric constant of the oil (eugenol), individual tubules were observed next to the bundled tubules. The results showed that straighter, bundled tubules are associated with firmer gels, whereas less straight (i.e. curly) tubules rendered weaker gels. The tubular network of the water-in-oil emulsions obtained for oils with a low dielectric constant appeared more open with straighter tubules. For oils with relatively high dielectric constant, the water-in-oil emulsions lost most of their tubular structure and only a few tubules could be observed. In the presence of emulsion droplets fewer tubules are formed, resulting in weaker networks.

The separation characteristics of two polyethersulfone membranes (molecular weight cut-off (MWCO) specification of 4 kDa and 10 kDa) for the retention of different dextran fractions (T2000, T40, T10) from aqueous solutions were systematically investigated, aiming at implementing them as a preparatory step for dextran analysis in sugar industry practice. Ultrafiltration is used to cause differences in optical rotation due to mechanical separation of dextran from aqueous solutions. The membrane separation performance was evaluated using polarimetry and size exclusion chromatography. It was found that the presence of sucrose leads to dramatically improved separation efficiencies for both membrane settings. Specific cut-off values for the separation of dextran from aqueous sucrose solutions have been determined, 10 kDa and 50 kDa for the membranes with a MWCO specification of 4 kDa and 10 kDa, respectively. The data indicate that the basic membrane setting (MWCO of 4 kDa) enables the complete separation and therefore the analytical quantification of the whole molecular mass spectrum relevant for sugar industry. The combination of both membranes, furthermore, indicates that it is suited for the differentiation between a high and a low molecular mass dextran fraction. The application of this new approach for the determination of dextran with varying molecular masses at various contents in synthetic thin juices as well as in real sugar beet raw juices indicates promising prospects.

This study was conducted to examine if the new temperature modulated optical refractometry (TMOR) method is applicable to study the phase behavior of alkyl-based components. n-Hexadecane, palmitic acid, and glycerol tripalmitate were used as model components. TMOR was benchmarked against differential scanning calorimetry (DSC) and polarized light microscopy (PLM). For all substances, a good agreement of the DSC data with TMOR was found. For n-hexadecane, a difference of 2.2 °C for the crystallization and 2.6 °C for the melting temperature was found. Considering palmitic acid, the crystallization temperature differed by 3.3 °C while the melting varied by 2.8 °C. The crystallization temperature of tripalmitate identified by TMOR was 2.7 °C higher, and the melting temperature 2.3 °C was lower compared to the DSC. The crystallization temperature for TMOR was always higher, and the melting temperature was always lower if related to DSC. This leads to the conclusion that TMOR is more accurate and direct. In addition, the transition peaks identified by TMOR were narrower compared to the DSC peaks. This is due to slower heating and cooling rates leading to a smaller temperature range of phase transition and less thermal lag. The study showed that TMOR is an appropriate method to determine the phase transition temperatures for the three examined substances. The results were comparable to the DSC data in both melting and crystallization behavior. Since the accuracy of TMOR is better at lower heating and cooling rates, it could be a reasonable extension of the well-known DSC method in the studies of melting and crystallization.

As Jatropha curcas L. is a non-edible energy plant biodiesel production from J. curcas L. crude oil is an important field of interest in order to avoid the 'tank or table' discussion. As a by-product from oil extraction, high amounts of Jatropha meals are obtained requiring a concept for its sustainable utilization. Due to the high protein content (up to 40 %) in Jatropha seed cakes, added value can be generated by extraction of these proteins for further applications. The present study compared an aqueous and an enzyme-assisted process for protein extraction from screw-pressed and aqueous de-oiled Jatropha residue. Additionally, different methods for protein recovery were evaluated. Aqueous-extracted proteins were recovered by ultrafiltration, isoelectric precipitation and/or lyophilisation while the proteins from enzyme-assisted extraction were only lyophilized. Functionality of the obtained protein products was determined indicating good emulsifying properties as well as a good gelation behaviour for the aqueous-extracted proteins. In general, proteins from enzyme-assisted extraction had slightly lower functionality. The study indicates potential for the application of Jatropha proteins as emulsifiers in biodegradable bags or as antifoam agents.