Influence of Polyphenol Levels on the Perception of Aroma in Vitis vinifera cv. Malbec wine

The aim of this study was to explore the effect of two ranges of polyphenols naturally present in Malbec wine,high concentrations (4.5-7.2 g/L) and low (1.4-3.2 g/L), on the perception of aroma. Samples with a maximumethanol level of 13.5% were taken from the fermentation tanks before the clarification and filtration process. AQuantitative Descriptive Analysis of wines was assessed by ten trained assessors, and HS-SPME-GC-MS andphysicochemical analyses were performed. The intensities of fruity (P < 0.01), citrus (P < 0.01), strawberry (P< 0.05), cooked fruit (P < 0.01) and floral (P < 0.01) aromas decreased when the level of polyphenols increased.Neither volatile compounds nor physicochemical analyses were significant in the two groups of wines

Scale influence on the energy dependence of photon - proton cross-sections

The scale dependence of the evolution of photoproduction cross sections with the photon-proton centre of mass energy W is studied using low Q 2 < 0.01 GeV 2 e + p interactions collected by the H1 experiment at HERA. The value of the largest transverse momentum of a charged particle in the photon fragmentation region is used to define the hard scale. The slope of the W dependence of the cross section is observed to increase steeply with increasing transverse momentum. The result is compared to measurements of the Q 2 evolution of the W dependence of the virtual photon-proton cross section. Interpretations in terms of QCD and in terms of Regge phenomenology are discussed

Bose-Einstein correlations in deep inelastic e p scattering at HERA

Two-particle correlations in invariant mass are studied separately for like-sign and unlike-sign charged particles produced in deep inelastic positron-proton scattering in a new kinematical domain. The data were taken with the H1 detector at the HERA storage ring in 1994, in which 27.5 GeV positrons collided with 820 GeV protons at a centre of mass energy sqrt{s}=300 GeV. The observed enhancement of the like-sign correlations at low invariant masses is related to the dimensions of the hadronic source. The data are compared to different QCD models where the hadronization is performed with the string-fragmentation model. Results are presented for the first time separately for diffractive and non-diffractive scattering, in domains of four-momentum transfer, Bjorken-x, and hadronic center of mass energy, and in intervals of charged particle multiplicity. The observed source radii do not differ strongly from those measured in lower energy lepton-nucleon inelastic scattering, and e^+e^- annihilation.Comment: 36 pages, 10 Figure