Vergleich von thermisch und photolytisch ausgelöstem Abbau von PVC-Preßlingen und -Folien

Comparative investigations of PVC discs and foils concerning their thermal and photolytical behaviour showed an expiration of thermal degradation in the mass, whilst the photo processes injure only the surface of a sample. The investigations of polymer samples with different masses have demonstrated a constant rate of thermal dehydrochlorination in nitrogen, which was not influenced by the polymer mass. The degradation experiments in air resulted in an increased HCl-elimination with increasing degradation time. Oxidation reactions which occur in the presence of air cause an accelerated degradation and therefore the dehydrochlorination reaction is appointed as an additional reaction and not in competition with the HCl-elimination process. The influence of UV-light on PVC-discs and foils efforted a much higher dehydrochlorination rate; the energy of the rays is able to stimulate all types of chlorine atoms at the surface. The photolytical injury of the surface increased with degradation time resulting in a decrease of the degradation rate. The degraded and cross-linked material is insoluble in all solvents.     

Gewinnung und Entbitterung von Speiseöl und Proteinkonzentrat aus Samen von Lupinus mutabilis

Production and Debittering of Edible Oil and a Protein Concentrate from Seeds of Lupinus mutabilis Lupine oil was produced from seeds of L. mutabilis using an extraction and refining process of soya oil. The refining included a step of debittering by washing with diluted acids. This decreased the alkaloid content from 0.14 % in the raw oil to 5 ppm in the endproduct, a content of rest alkaloids, which can be considered as unobjectionable. The oil alkaloids are not identical with those of the seeds. While in seeds Lupanin is the main alkaloid fraction, in the oil 13-Hydroxylupanin and N-Methyl angustofolin are dominant. The raw oil contained 800 ppm γ-Tocopherol 39 ppm α-Tocopherol. During the refining process the Tocopherol content decreased from about 840 ppm to 530 ppm total Tocopherol in the endproduct. The oil-cake contained about 4 % alkaloids. With aqueous alcohol (70 %?90 % ethanol) was debittered to a protein concentrate, which contained 73% protein and 0.06% rest alkaloids. By changing the pH value of the debittering medium both in the acid (pH 5) and alkaline (pH 9) range the alkaloid extraction could be improved and the loses of protein could be diminished. Qualitatively the alkaloid pattern of the protein concentrate was similar to that of seeds, although the hydroxylupanin fraction increased from 32.7% of total alkaloids before the debittering to 42.3% in the debittered concentrate. This is advantageous because the toxicity of hydroxylupanin is only about 1/10 of that of Lupanin.     

Dünnschicht- und Gaschromatographie von Tocopherolen

Thin-Layer end Gas Chromatography of Tocopherols Oilseeds, to which an internal standard of tocopherol was given, were extracted for tocopherols with ethanol under conditions inhibiting oxidation using an Ultra-Turrax homogenizer. After filtration the ethanolic extract is briefly saponified and the unsaponifiable matter containing the tocopherols extracted into n-hexane. Then the hexane-fraction is washed alkalifree with water, dried over Na₂SO₄, concentrated and applied on a silicagel GF₂₅₄-plate, which is developed with dichloromethane. With co-chromatographed reference-tocopherols on the margins of the TLC-plate the presence of tocopherolquinones can be checked in UV-light, whereas the bands of tocopherols and tocotrienols are located by spraying the margins with Emmerie and Engel-reagent. The corresponding zones were scrapped off the plate, the silicagel extracted with 15 × 1 ml ethanol, the ethanol evaporated to dryness and the residue derivatised to trimethylsilylethers. Gaschromatography on 3 m SE-52/XE-60 or 1.5 m SE-30 columns gave a good separation of tocopherols and tocotrienols. Simultaneous qualitative and quantitative determination of tocopherols by GLC combined with the possibility of automation makes this analytical procedure superior to TLC and colorimetry of tocopherols. About 500 tests with different oilseeds in the range between 50-800 mg lipid and 20-2000 μg of total tocopherol/sample gave a recovery of 60% at a coefficient of variation of approximately 6%.