Biogene Amine in Lebensmitteln. Eigene Untersuchungen in Wein und Sauerkraut

Zusammenfassung Nach einigen Betrachtungen über Verträglichkeitsfragen bei der Einnahme aminhaltiger Nahrungsmittel werden die Ergebnisse von Untersuchungen über die Gehalte an nichtflüchtigen Aminen in Wein und Sauerkraut aufgeführt. In Wein und Sauerkraut wird Histamin durch Milchsäurebakterien der Art Pediococcus cerevisiae gebildet. Verschiedene weitere Amine, z.B. Tyramin, Putrescin und Phenyläthylamin, werden während des biologischen Säureabbaus in Wein ebenfalls durch Milchsäurebakterien produziert.

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Biogenic amines in food. Investigations in wine and sauerkraut

After some remarks on compatibility problems of food containing biogenic amines, results are presented on non volatile amine content in wine and sauerkraut. In wine and sauerkraut, histamine is produced by lactic acid bacteria of the Pediococcus cerevisiae species. Several other amines, e.g. tyramine, putrescine and phenylethylamine are also formed during malo-lactic fermentation in wine by lactic acid bacteria.

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Vortrag, gehalten auf dem VIII. Internationalen Kongreß für Qualitätsforschung der CIQ zusammen mit der Deutschen Gesellschaft für Qualitätsforschung (DGQ) in Wädenswil/Schweiz vom 7. – 10. Oktober 1975.     

Quality assessment and quantitative analysis of flavonoids from tea samples of different origins by HPLC-DAD-ESI-MS

Components of green tea ( Camellia sinensis) have been of considerable interest in recent years because of their potential utility as pharmaceutical agents, particularly for their antioxidant and anticarcinogenic activity. Responding to the increasing scientific validation of numerous health benefits of tea, a comprehensive approach was adopted to carry out analysis for the quality assessment of flavonoids in tea samples of different origins. For this purpose, extraction, separation, and mass spectrometric parameters were optimized. Extraction methods evaluated include reflux extraction, a modified accelerated solvent extraction (ASE), namely, Aquasolv extraction, and microwave-assisted extraction (MAE) using different percentages of solvents. Separation was performed by a specifically developed reversed phase high-performance liquid chromatography (RP-HPLC) method using different C18 and C8 stationary phases. Optimization of extraction techniques clearly proved the performance of MAE, which delivered highest yields in a very short time. Additionally, the comparison with Aquasolv extraction provided new insights, as variations in quantified amounts of target compounds between the extracts could be explained on the basis of thermal degradation and epimerization phenomena. Especially the epimerization phenomenon for catechin/epicatechin oligomers, that is, of procyanidins P 2 and P 3, was observed for the first time. Finally, an optimized extraction and separation system was used for qualitative and quantitative investigations of compounds from different green tea samples from Ceylon (cultivated under biologically controlled conditions), Japan, India, and China as well as from one black tea sample from India.     

Erythromycin Exposure Disrupts the Life Cycle Stages of <Emphasis Type="Italic">Aedes aegypti</Emphasis> L. (Diptera: Culicidae)

Erythromycin is one of the most widely used antibiotics globally and is considered an emerging contaminant in wastewaters and environmental waters. The egg, larval, and pupal stages of the dengue vector Aedes aegypti L. reside and develop in aquatic environments. These mosquito stages may be exposed to compounds in the water, such as erythromycin. Aquatic stages of Ae. aegypti were reared in different concentrations of erythromycin which resulted in significant delay and decrease in eclosion of eggs and pupation of larvae (P?<?0.05). Moreover, emergence of adults from pupae, larval survival, and adult female fecundity significantly decreased (P?<?0.05). A few occurrences of hypopigmentation in larvae and blisters in adult mosquitoes were also observed. Interestingly, second-generation eggs, which were laid by adult female mosquitoes exposed to erythromycin during their aquatic stages, did not exhibit decreased levels of eclosion in the presence of erythromycin. These results reveal that long-term erythromycin exposure disrupts the Ae. aegypti life cycle by decreasing survival and delaying progression throughout different life stages. However, this study demonstrates that Ae. aegypti can rapidly acquire significant tolerance to the emerging environmental contaminant erythromycin within two generations.     

III. Buchbesprechungen

Ohne Zusammenfassung