Effect of storage time and temperature on the volatile composition and quality of dry white table wines

Dry white wines of the cultivars Chenin blanc, Riesling and Colombar (1978 vintage) were stored at 0, 10, 20 and 30 °c for 12 months. Another Colombar wine (1977 vintage) was stored under similar conditions for 2 years. The 1978 wines were analysed periodically by gas chromatography for esters, higher alcohols and dimethyl sulphide and sensorily evaluated for young wine bouquet, maturation bouquet and total wine quality. Increases in storage time and temperature caused marked decreases in the concentrations of i-amyl acetate, hexyl acetate, 2-phenethyl acetate, ethyl butyrate, ethyl caproate, ethyl caprylate, ethyl caprate, total esters and young wine bouquet and marked increases in the· concentrations of dimethyl sulphide, diethyl succinate, ethyl acetate and total aldehydes as well as optical density and maturation bouquet. Highly significant relationships were found between chemical components and the percentage scores of the wines determined by sensory evaluations. The effect of time and temperature on the ageing of white wines can be utilized in practice either to preserve the young wine bouquet for an extended period of time or to produce a well-aged wine within a short period.Einfluß der Lagerungsdauer und -temperatur auf die Aromazusammensetzung und Qualität trockener weißer TafelweineTrockene Weißweine der Sorten Chenin blanc, Riesling und Colombar (Jahrgang 1978) wurden bei 0, 10, 20 und 30 °c 12 Monate lang gelagert. Ein anderer Colombar-Wein (Jahrgang 1977) wurde unter ähnlichen Bedingungen 2 Jahre lang gelagert. Die 1978er Weine wurden mittels Gaschromatographie regelmäßig auf Ester, höhere Alkohole und Dimethylsulfid analysiert sowie sensorisch auf Jungweinbukett, Reifebukett und gesamte Weinqualität geprüft. Zunehmende Lagerungsdauer und Lagerungstemperatur bewirkten eine deutliche Abnahme bei der Konzentration von iAmylacetat, Hexylacetat, 2-Phenyläthylacetat, Äthylbutyrat, Äthylcapronat, Äthylcaprylat, Äthylcaprinat, gesamten Estern und beim Jungweinbukett sowie eine ausgeprägte Zunahme bei der Konzentration von Dimethylsulfid, Dilithylsuccinat, Äthylacetat und gesamten Aldehyden, bei der optischen Dichte wie auch beim Reifebukett. Zwischen den Inhaltsstoffen und den Ergebnissen der sensorischen Prüfung wurden hochsignifikante Korrelationen gefunden. Der Einfluß von Lagerungsdauer und -temperatur auf die Alterung von Weißweinen kann praktisch genutzt werden, um entweder das Jungweinbukett über einen längeren Zeitraum hinweg zu erhalten oder um innerhalb kurzer Zeit einen angenehmen gealterten Wein zu erzielen

Overview on sugar metabolism and its control in Lactococcus lactis - The input from in vivo NMR

The wide application of lactic acid bacteria in the production of fermented foods depends to a great extent on the unique features of sugar metabolism in these organisms. The relative metabolic simplicity and the availability of genetic tools made Lactococcus lactis the organism of choice to gain insight into metabolic and regulatory networks. In vivo nuclear magnetic resonance has proven a very useful technique to monitor non-invasively the dynamics of intracellular metabolite and co-factor pools following a glucose pulse. Examples of the application of this methodology to identify metabolic bottlenecks and regulatory sites are presented. The use of this information to direct metabolic engineering strategies is illustrated. (c) 2005 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved

Harnessing the senga institution of adolescent sex education for the control of HIV and STDs in rural Uganda.

Senga (father's sister) is a traditional channel of communication about sexual behaviour for adolescent females in rural Uganda. We evaluated a modification of this approach as an intervention for HIV and STDs in a pilot study in two intervention villages and one control village over 12 months. Eleven adult women and three adolescent girls were chosen and trained to become sengas. Adolescent girls were encouraged to visit the sengas for sexual health information. Adult sengas saw an average of 21 clients; adolescent sengas saw five. Adolescent girls made 45% of visits. The expected reasons for attending the sengas accounted for 51% of visits. Knowledge about HIV/AIDS, sexual communication skills, consistent condom use and family planning service use increased in the intervention group of girls over the study period and compared to control girls. Symptomatic STDs decreased in the intervention group. This intervention was readily accepted by the community; members of all ages and both sexes attended for a wider variety of reasons than anticipated. Adolescent girls in the intervention group showed improved knowledge, attitudes and practices related to HIV and STDs. This promising intervention warrants further testing in larger studies and other settings

Regularization of the Roy Equations with a Smooth Cut-Off

The Roy equations for ππ scattering are combined with unitarity to give a nonlinear system of equations for the determination of the low‐energy amplitudes. A Hölder continuous interpolation between the input high‐energy absorptive parts and the output low‐energy absorptive parts is implemented; and the resultant singular equations are regularized by means of an effective inelastic N/D method. If the scattering lengths, the CDD parameters, and the high‐energy absorptive parts satisfy certain constraints, then there exists a locally unique solution of the system

Herkunft als Weg: Migrationsforschung nimmt zunehmend die Komplexität von Routen in den Blick

Migrationsrouten kön-nen sich über Jahrzehnte und sogar über Generationen erstrecken. Ein Forschungsprojekt, bei dem über vier Jahre hinweg Menschen auf Migrati-onsrouten von Afghanistan nach Deutschland begleitet wurden, zeigt, dass sich die Bedeutung von Herkunft entlang dieser Wege sowohl persön-lich als auch nach externen Definitio-nen und Kategorisierungen verändert.Migration trajectories can span decades and even generations. Four years of research along migra-tion routes from Afghanistan to Ger-many revealed that the meaning of origin changes along these routes, both personally and according to ex-ternal definitions and categorizations

Microminiaturized, biopotential conditioning system (MBCS)

Multichannel, medical monitoring system allows almost complete freedom of movement for subject during monitoring periods. System comprises monitoring unit (biobelt), transmission line, and data acquisition unit. Belt, made of polybenzimidizole fabric, is wrapped around individual's waist and held in place by overlapping sections of Velcro closure material

The Drosophila genome nexus: a population genomic resource of 623 Drosophila melanogaster genomes, including 197 from a single ancestral range population.

Hundreds of wild-derived Drosophila melanogaster genomes have been published, but rigorous comparisons across data sets are precluded by differences in alignment methodology. The most common approach to reference-based genome assembly is a single round of alignment followed by quality filtering and variant detection. We evaluated variations and extensions of this approach and settled on an assembly strategy that utilizes two alignment programs and incorporates both substitutions and short indels to construct an updated reference for a second round of mapping prior to final variant detection. Utilizing this approach, we reassembled published D. melanogaster population genomic data sets and added unpublished genomes from several sub-Saharan populations. Most notably, we present aligned data from phase 3 of the Drosophila Population Genomics Project (DPGP3), which provides 197 genomes from a single ancestral range population of D. melanogaster (from Zambia). The large sample size, high genetic diversity, and potentially simpler demographic history of the DPGP3 sample will make this a highly valuable resource for fundamental population genetic research. The complete set of assemblies described here, termed the Drosophila Genome Nexus, presently comprises 623 consistently aligned genomes and is publicly available in multiple formats with supporting documentation and bioinformatic tools. This resource will greatly facilitate population genomic analysis in this model species by reducing the methodological differences between data sets