Analyse flüchtiger Inhaltsstoffe des Holunders

European Food Research and Technology - Die Analyse und Identifizierung von Aromastoffen mittels GC/MS-Technik aus Holunderbeeren und -blüten wird beschrieben. Durch Extraktion mit...     

Chromium in Austrian foods

The chromium content in foods is relatively low and the most foods have a content below 0.1 ppm. Only spices, cacao, cacao products, poppy and whole meal products contain higher contents. The often published high chromium content of corn germ oil could not be verified. We did not find any chromium enrichment in the entrails of a cow. In addition the chromium contents of each food are strong deviated. The analysed values were sometimes lower than in literature. We expect that the elder values are higher because of different contaminations in some cases.     

Formation of α-Tocopherolquinone and α-Tocopherolquinone Epoxides in Plant Oil

The antioxidative activity of α-tocopherol in oil is necessary for the inhibition of lipid peroxidation. If no regeneration of antioxidants is possible in foods, oxidation products are formed to a measurable extent. The aim of this study was to investigate oxidation products of α-tocopherol in plant oil. The oxidation of α-tocopherol in plant oil leads to α-tocopherolquinone and to two epoxides (α-tocopherolquinone-2,3-epoxide, α-tocopherolquinone-5,6-epoxide). These three reaction products were identified and quantified in plant oil. The 2,3-epoxide is formed at lower temperatures (90°C) whereas at high temperatures (180–220°C) only the 5,6-epoxide appears. The kinetics show that the 5,6-epoxide is produced as long as α-tocopherol is present. With longer reaction times the concentration of the 5,6-epoxide starts to decrease. α-Tocopherolquinone is found at substantially lower concentrations.     

Mass spectroscopy-gas cromatographic identification of chlorinated hydrocarbons in trout

The PCB-content and the content of chlorinated hydrocarbons in trout was examined by GC-MS. PCBs ranging from trichlorobiphenyls to hexachlorbiphenyls, chlordan, DDE, DDD, DDT and dieldrine were found and identified by mass spectrometry. We suppose that less chlorinated PCBs in trout are not deposed or will be excreted very quickly.     

Vergleich dreier Methoden zur Bestimmung von Zinn in Konserven

Zusammenfassung Ein Vergleich dreier Methoden zur Bestimmung von Zinn in Dosenwaren wird durchgeführt. Eine Redoxtitration, eine photometrische Bestimmung mit Quercetin und eine Bestimmung mittels Atomabsorptionsspektraphotometrie nach Extraktion mit Methylisobutylketon werden auf ihre Anwendbarkeit und mögliche Störungen hin untersucht. Die Redoxtitration ist bei Zinngehalten > 50 ppm, die Quereetinmethode für Gehalte über 20 ppm. und die Atomabsorptionsmethode über den von uns überprüften Konzentrationsbereich von 5–1000 ppm. anwendbar. Auf einige Beeinträchtigungen der photometrischen Methode, sowie auf die optimalen Bedingungen der Extraktion von Zinn mit Methylisobutylketon und seine nachfolgende Bestimmung durch Atomabsorption wird hingewiesen.

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Comparison of three methods for the determination of tin in canned food

Summary Three analytic methods to determine tin in preserves were compared. Redoxtitration, a photometric procedure with quercetine and an AAS-method after isolation of tin by extraction with methylisobutylketone were examined. The redoxtitration is suitable above 50 ppm tin, the quercetine procedure upper 20 ppm, while the AAS-method is practicable within the range 5–1000 ppm. Some interferences in the case of the quercetine-method are noted and optimal conditions for extraction of tin and the determination by AAS are given.

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Diese Arbeit wurde aus Mitteln des Forschungsförderungsfonds der gewerblichen Wirtschaft Österreichs gefördert.