Key Aroma Compounds in Two Bavarian Gins

The characteristic, dominant flavor of gin is juniper, often within a complex aroma of other botanicals. The present study examined two gins from a distillery in the German state of Bavaria; one produced with 50 individual botanicals, the other with 15. The study focused on characterizing the aroma profiles and identifying the key aroma-active compounds of the gins. Comparative sensory evaluations of the gins revealed marked differences in their aroma profiles, with the botanical-rich gin exhibiting more citrusy, orangey and fruity notes than the gin containing fewer botanicals. Instrumental analyses by gas chromatography-mass spectrometry/olfactometry (GC-MS/O) using aroma extract dilution assays (AEDA) identified terpenes as the dominant key aroma compounds, specifically limonene, 1,8-cineole, linalool, estragole and trans-anethole, with additional contributions from aldehydes, such as nonanal, and phenylpropanoids, such as eugenol and estragole. Selected compounds were quantified using stir-bar sorptive extraction (SBSE) and stabile isotope dilution analysis (SIDA) with GC-MS analysis. Further, odor thresholds and corresponding odor activity values (OAVs) of these compounds were calculated, with linalool exhibiting the highest OAV in both gins. The present analyses revealed how different botanicals alter the concentrations of key aroma compound constituents and elicit a shift in the overall aroma profile of the final spirit.

Environmental hydrochemical and stabile isotope methods used to characterise the relation between karst water and surface water

Karst aquifers are characterized by high heterogeneity of groundwater flow. The classical study methods such as boreholes, pumping tests, and point observations give important data but cannot be extended to the entire aquifer. However the environmental hydrochemical and stabile isotope methods could give important information about large scale aquifer characterization. Some study examples from Albania, shown in this paper, demonstrate the successful application of the isotope methods, which are more powerful if applied in combination with hydrochemical ones, for the identification of the karst water recharge sources. Among the isotope methods the altitude effect seems to be more indicative for the solution of the problem concerned. For characterising the lithology of karst rocks and the physical aspects of karst aquifers (type of groundwater flow) the combined use of some hydrochemical parameters like the water conductivity, total hardness, ionic ratios rCa/ rMg, rSO4/r/mg, CO2 pressure and the indexes of calcite and (Sic) and of dolomite saturation (Sid), result very useful.

Quartäre Klimaschwankungen : Schätzung der Temperaturschwankungen in Grönland mittels hochaufgelöster Isotopenmessung an im Eis archivierter Luft

Eisbohrkerne bieten einen Zugang zu klimatischer Information, welche zeitlich gut geordnet und in hoher Präzision ausgemessen werden kann. Stabile Isotope in Wassermolekülen können relativ einfach mit hoher Genauigkeit gemessen werden und geben einen ersten Eindruck, wie sich die lokale Temperatur zeitlich verändert hat. Allerdings dürfen die Isotopenvariationen des Wassers nicht 1: 1 in lokale Temperaturen umgesetzt werden, da es neben der Temperatur auch noch andere Einflussgrössen gibt, wie die Quellentemperatur und die jahreszeitliche Niederschlagsverteilung. Variationen von Stickstoffisotopen aufgrund der Thermodiffusion erweisen sich als sehr guter Temperatur- Proxy für grosse und schnelle Temperatursprünge, wie dies die Dansgaard- Oeschger- Ereignisse darstellen. An North- GRIP- Eis wurden mit dieser neuen Methodik Temperatursprünge zwischen 8 und 15° C für die Dansgaard- Oeschger- Ereignisse 8–17 gemessen. Die Genauigkeit dieser Temperatursprünge beträgt ca. 3°C.