Optimisation of mild-acidic protein extraction from defatted sunflower (Helianthus annuus L.) meal

For protein isolation from defatted sunflower meal, mild-acidic extraction was investigated to minimise concomitant oxidation and polymerisation of phenolic compounds and their irreversible binding to proteins. Because of the impaired solubility of sunflower proteins at low pH, the potential of sodium chloride (NaCl) to improve protein extractability was firstly screened for pH 2–11. Increasing NaCl concentrations of the aqueous solvent (c_NaCl) up to 2.8 mol/L enhanced the relative protein yield to almost 80% at ambient temperature and pH 5.6–7.4. As to improved protein recovery at minimal interactions with phenolic acids, the concerted effects of pH (3.2–7.4), c_NaCl (1–3 mol/L), temperature (T, 15–45 °C), and meal-to-solvent ratio (MSR, 0.03 and 0.05 g/mL) on the protein concentration of the extract (c_PE) and the relative protein yield (RPY) were examined, using response surface methodology (RSM). Aside from the prevailing influence of pH value and salt concentration, elevated temperature slightly enhanced protein extraction, whereas MSR mainly influenced c_PE, but hardly RPY. Calculated models proved suitable for the evaluation of extraction processes and the prediction of optimum conditions in terms of high protein yields at the lowest pH possible. Extraction at pH 6.0 was shown to be an appropriate compromise yielding 76–83% of the meal protein, depending on the constraints given. With elevated NaCl concentrations compensating for unfavourable pH conditions, mild-acidic extraction was found to be suitable for the recovery of high-quality sunflower protein in terms of light-coloured protein isolates.     

A New Validation of Relevant Substances for the Evaluation of Beer Aging Depending on the Employed Boiling System

During the last years changes in aging indicators have been observed, supposedly resulting from modern brewing technology. The Research Brewery Weihenstephan (Forschungsbrauerei Weihenstephan) offers excellent opportunities for comparing different modern wort boiling systems under semi‐industrial conditions. Employing three different boiling systems, nine brews were produced. The resulting worts were compared regarding the most common wort parameters. Furthermore the influence of the different boiling systems on aging indicators in the resulting beers was analyzed using a newly developed mass spectrometry‐based method. The decrease in the total amount of aging indicators in industrial beers over the last years is very likely the result of lower thermal intake in modern brewhouse equipment. The total amount of aging indicators is sufficient to describe the differences in modern boiling systems. In summary, 2‐furfural dominates all other indicators in terms of thermal influence. 2‐Furfuryl ethyl ether can be suggested as good indicator of aging as postulated by Eichhorn, whereas β‐damascenone is questionable as an aging indicator. Supplementary experiments were carried out to investigate the role of the aging indicators as stale flavour components. Because of synergistic effects, many stale flavour compounds act as aroma compounds and not only as indicators.     

Determination of Relaxation Moduli and Poisson‘s Ratio in Uniaxially Loaded Solid Polyethylene Foam Specimens as Part of Full Material Characterization

The mechanical behavior of a solid polyethylene foam is characterizedby a constitutive equation which is of second order in the linearstrain tensor. It turns out that for the determination of the sixtime dependent material functions relaxation tests intension/compression, torsion and, for instance, in isotropic tension andcompression are necessary. For tension/compression tests theexperimental procedure is described in detail. Main emphasis is givento the methods of optical deformation measurement techniques. Resultsfor the relaxation moduli in tension/compression and for the Poissonsratio are presented.     

Carbon nanotubes and mesenchymal stem cells: biocompatibility, proliferation and differentiation

The synergy of the unique properties of carbon nanotubes (CNT) with the remarkable potential of human mesenchymal stem cells (hMSC) provides an exciting opportunity for novel therapeutic modalities. However, little is known about the impact of CNT on hMSC behavior. We report the effect of CNT on hMSC renewal, metabolic activity, and differentiation. Furthermore, we tracked the intracellular movement of CNT through the cytoplasm to a nuclear location and assessed effects on cellular ultra structure.     

Application of infrared ATR spectroscopy to in situ reaction monitoring

The infrared horizontal ATR technique was adapted to be applied for in situ reaction monitoring even at high pressure and high temperature. Different types of reactors and flow cells were built which can be used for recording IR ATR spectra at pressures up to 200 bar and temperatures up to 300°C.

The use of the horizontal ATR technique is shown by the following application examples:

• addition reaction of n-butyl isocyanate with butyric alcohol;

• investigation of the equilibrium of isocyanate, HCl and carbamic acid chloride at elevated pressure and temperature;

• monitoring the polycondensation of bifunctional alcohols and carbonic acids;

• recording spectra of polymer melts at 280°C.

Aus Luftschiffhalle wird Tropischer Regenwald ndash; Brandschutzkonzepte für die größte Halle der Welt

From an airship dockyard to a tropical rainforest ndash; fire protection concept for the the largest hall construction of the world. Tropical Islands is a project with enormous dimensions and very specific utilizations. It is used as a dockyard for large cargo airships as well as for recreational and event presentation purposes with a tropical rainforest in it. This article does not show the complete fire protection concept but has represented certain aspects and focal points that transcend the project and could be of general interest. The results of smoke tests and their specific implementation concerning the particular conditions of the dockyard were shown to point out the very special question of smoke exhaust venting. For the intended new usage of the building the effectiveness of the measures was tested systematically under various conditions and trough successive mathematical approximation. In this case it was pointed out that it was more important to see the superior context than to simulate single scenarios. This cognition may also be useful for projects which are less spectacular. This project is an ideal example to show how largely fire protection measures must and can be adapted to the specific usage of the building. This aspect becomes more important especially in times where buildings were used in other ways as they were intended originally because of economical decisions or simply to conserve resources.     

Das Scaling‐Down‐Problem bei der Zweistoff‐Gaszerstäubung von Metallschmelzen

The production capacities of plants for metal pulverisation are frequently rated according to the minimum throughput of melt flowing from the distributor crucible to pulverisation. Especially in the case of high‐melting point metals and their alloys deficiencies occur in the thermal balance of the crucible in the exit section as a result of gas expansion at the pulverisation gas jets, which act as heat sinks. Minimum throughputs and associated limiting values of the convective heat transfer of the melt are stipulated in order to prevent "freezing" (solidification of the melt) in the crucible. The pertinent situation is illustrated for copper and steel melts and technical possibilities for compensating for heat deficiencies by inductive heating of the distributor exit are presented. In addition, the demand for minimum throughputs can be abandoned, and there result possibilities of scaling‐down and energy conservation as well as improvement of powder discharge.