Trennpressen geschälter Rapssaat – Zielsetzung und verfahrenstechnische Probleme

Expression of dehulled rapeseed - Targets and processing problems. Environmental reasons are of prime importance for the use of rapeseed oil as raw material for lubrication oils and hydraulic fluids with a high biological decomposition rate. Thus, the task for oil processing is to minimize the loss of hexane in extraction meals. Hexane retention is essentially caused by rapeseed-hull oils. Only a small part of the hull lipids is released from the extremely strong structure of the hulls. The residual lipids absorb hexane. In order to reduce residual hexane in the extraction meal it is suggested to dehull the rapeseed during preprocessing. A process of dehulling rapeseed by defined deformation is described. The operation of a screw press separating oil is essentially determined by the elasticity and permeability of the compressed material. Therefore, the natural content of hull is considered indispensable in the practice of oil milling. The observed orientation of hulls in technical press cakes, however, challenges this assessment. As a result, questions arise concerning the properties of dehulled rapeseed in pressed state. It is necessary to determine the minimum content of hulls for a sufficient elasticity and permeability under compression and for a solid press cake on condition that there will be a considerable decrease of residual hexane by reducing hulls to this amount.     

Qualitätsbestimmende Eigenschaften bei der Verarbeitung von Rapssaat

Characteristics of Quality for the Processing of Rapeseed Among quality characteristics of oilseeds high extraction rates by the lowest possible technical expenses rank first for oilmilling. Apart from weight of cargo, oil content, humidity and contamination are therefore the most decisive determinants of price quotations. But for efficient oil extraction further criterions are essential such as structure and hardness of the seed, content of free fatty acids, phospholipids (gums), unsaponifiables, colour bodies or pollutants. In addition, the nutritional qualities of the meal, especially its content of glucosinolates and protein, deserve increasing interest. Each of these characteristics typically differs in its modificability by means of breeding and processing. From two experiments with industry scale processing of rapeseed from new varieties low in erucic acid and glucosinolate, results were obtained in 1975 and 1976 confirming the technological equivalency of the traditional and the new rapeseed varieties. Simultaneous genetic improvement of oil and protein content is limited by a negative physiological correlation between these two important quality characteristics. But probably the maximum capacity with regard to these traits is not yet realized in the present varieties. According to the results of an experiment with more than 4000 plants and their progenies progress in protein selection varies within different subgroups of a total of breeding stocks preselected for oil content and thousand-seed-weight, respectively.     

Rheologische Eigenschaften von Metallseifen in konzentrierten wäßrigen Dispersionen

Rheological Properties of Metal Soaps in Concentrate Aqueous Dispersions The rheological behavior and the particle size distributions of calcium stearate dispersions were examined. From these investigations it is possible to propose a suitable quality profile for metal soap dispersions. For the handling of the dispersions it is advantageous if these products have a newtonic up to a slight pseudoplastic flow behavior with an average of particle size clear under 10 microns. A quality control should comprise the analysis of alcalinity, water content, rheological behavior and particle size distribution.     

Kapillarkräfte in Suspensionen: Rheologische Eigenschaften und potenzielle Anwendungen

It has been found that in suspensions capillary forces play an essential role between the disperse phase and the continuous phase in respect of their rheological behavior. In this review it is shown, that the rheological behavior of a disperse phase, which is dispersed in a continuous phase, can be changed significantly by adding a small amount (< 1 %) of a secondary liquid that is not mixable with the bulk phase. This effect now can be used to modify product properties specifically.     

Aktivkohle aus Phenolharz mit gepreßten Olivenkernen als Füllstoff

A new activated carbon is prepared using phenolic-resin (type novolac) with pressed olive stones. The last-named material is an agriculture by-product produced yearly in large amounts mainly in mediterranean countries. Both materials are mixed in different proportions, cured and carbonized until 1000°C. The weight loss and the shrinkage during the process are measured. The specific surface areas of the carbonaceous residues being in different shapes (e.g. pellets, powder) are also determined. The ability of these carbonaceous materials to adsorb methylene blue dye from its aqueous solution is examined and it is found, that the adsorption process follows the Freundlich equation.     

Fettpolymere – Herstellverfahren und Eigenschaften

The radical polymerization of esters of acrylic, methacrylic or crotonic acid with fatty alcohols proved to be an efficient method for production of polymers with hydrophobic moieties. By co-polymerisation with hydrophilic co-monomers - such as maleic anhydride - copolymers with a broad spectrum of properties can be designed. As an example the copolymerisation of fatty crotonates with maleic anhydride was studied in detail. The reaction was carried out as bulk polymerisation in a semi-batch process. By this method the compatibility problems of the two monomers, which have very different hydrophilicities could be overcome. The product acts as a very effective fat liquoring agent in leather treatment: the maleic moieties cause an outstanding fixing of the agent on the leather and the fatty crotonate moieties create a very smooth leather. Terpolymers of fatty acrylates, hydrophilic monomers and terpenes could also be synthesized in a similar way. These terpolymers proved to be useful as dispersing agents for pigments in paints and varnishes.     

Standortgefertigte Druckbehälter

On-site construction of pressure vessels . The area encompassed by on-site construction of pressure vessels is so vast that a complete survey is far beyond the scope of this article. On the whole, only spherical pressure vessels suitable for compressed or liquefied gases are dealt with. Other large vessels such as reactors and safety mantles are only briefly mentioned. Of prime interest is the state of the art, the many associated problems and development trends, and last but not least the constantly growing safety requirements of the population regarding technological developments.     

3β-Chlorsteroide – Ernährungsphysiologische und toxikologische Eigenschaften in Mäusen

3β-Chlorosteroids - Nutritional and Toxicological Effects in Mice 3-Chlorosteroids, e.g. 3-chlorocholest-5-ene and 3-chlorostigmast-5-ene, are formed from the corresponding sterols during the industrial hydrolysis of proteins for the production of flavor enhancers. In future, these compounds may also attract attention as environmental contaminants. A simple method for the fractionation and quantitative determination of 3β-chlorosteroids by C₁₈ reversed-phase HPLC has been developed and used for the analysis of these chlorinated steroids in protein hydrolysates. In addition, the biological effects of orally administrated 3β-chloro-steroids were tested in mice that were fed 3β-chlorocholest-5-ene and 3β-chlorostigmast-5-ene in doses of 1 and 10 mg/animal/day. The results of our study showed that body and organ weights as well as feed intake of the various experimental groups were not significantly different from those of the control group. The quantitative determination of 3β-chlorosteroids in organs and tissues revealed that intestinal absorption of 3β-chlorocholest-5-ene was higher than that of 3β-chlorostigmast-5-ene. Highest concentration of 3β-chlorocholest-5-ene was detected in liver and adipose tissue. Absorption and distribution in tissues as well as metabolism of both radioactive 3β-chloro-[4-¹⁴C]cholest-5-ene and 3β-chloro-[4-¹⁴C]stigmast-5-ene have also been studied in mice. At 2 hours after stomach incubation of the two substrates, large proportions of radioactivity had passed through the small intestine and were concentrated in the contents of caecum and colon. Only small proportions of radioactivity were detected outside the alimentary canal, predominantly in the liver. Histopathological examination of sections of organs and tissues such as stomach, duodenum, liver, kidneys, and spleen showed no indications of irreversible cell damages caused by 3β-chlorosteroids.     

Struktur und spektrale Eigenschaften des Pentamethinmerocyanins 5‐(Dimethylamino)pentadienal in Lösung – Eine kombinierte DFT–SCI–SCRF–Studie

In order to estimate the solvent effect on molecular structure and on NMR and UV spectral data of 5‐(dimethylamino)penta‐2,4‐dien‐al(1) ( 1 , R = Me) the compound was calculated by first‐principles methods. Density functional theory was employed for structural optimization with solvent effects simulated by the recently refined COSMO continuum model. According to the calculations the molecular structure of 1 (R = Me) is noticeably affected by polar solvents resulting in a reduced bond length alternation. The relaxation of the molecular geometry in polar solvents is clearly reflected in the calculated ¹³C NMR chemical shifts calculated by GIAO‐DFT and in the absorption wave numbers of the intense lowest‐energy electronic transition calculated by SCI. Although the optimum geometry of the solute molecule in the solvents was calculated the magnitude of the solvatochromic shift is underestimated. The calculated solvatochromic effect in water is enhanced if the specific solvent‐solute interactions are considered by addition of one water molecule to 1 (R = Me) in the solvent cavity.