55 research outputs found
Enhancing Phenolic Maturity of Syrah with the Application of a New Foliar Spray
Climate change is inducing earlier grape ripening, especially in warm vintages. This phenomenon isresulting in unbalanced wines an alcohol concentration that is too high and titratable acidity that is low,along with a high pH level without the desired level of phenolic maturity. Final wine quality notably dependson the phenolic composition of the grapes and the extractability of these compounds. This research wasdesigned to test a new foliar spray, called LalVigne® MATURE, for its capacity to create a balance betweensugar development and phenolic maturity. It is a formulation of 100% natural, inactivated wine yeastderivatives. This foliar spray was tested on Syrah vines in two vintages (2012 and 2013) in a cool-climatewine region (Eger, Hungary). The spray acted as an elicitor, stimulating the synthesis of several secondarymetabolites. The changes in anthocyanin extractability and texture characteristics of the grape berrieswere followed during ripening. Experimental wines were made at three separate harvest times in eachvintage. Standard analytical parameters were evaluated for grapes and wines, as well as for resveratrol.Grapes from the treated vines had thicker skins than the controls at all sampling dates in both vintages.The phenolic potential (especially anthocyanin concentration and extractability) of the foliar spray-treatedgrapes was greatly improved. Our experiment showed that phenolic ripening can be enhanced using thefoliar spray, and that its application was useful in different vintages
Relationship Between Biogenic Amines and Free Amino Acid Contents of Winesand Musts from Alentejo (Portugal)
The concentration of biogenic amines and free amino acids was studied in 102
Portuguese wines and 18 musts from Alentejo demarcated (D.O.C.) regions. Most wines
were commercial, except for 38 monovarietals obtained by micro vinification. Musts
from the varieties used to produce the latter wines were also studied. Both biogenic
amines and free amino acids were analyzed by HPLC using fluorescence detection for
their o-phthalaldehyde/fluorenylmethyl chloroformate (OPA/FMOC) derivatives. The
most significant amines (average 10.8 mg/L for histamine+tyramine in red, and 7.4
mg/L for white wines) were found to be present at low levels and, although no important
relationship between each individual biogenic amine could be obtained, the total amine
content depends significantly on the assimilable amino acid content in wine
Solvation and Protonation of Coumarin 102 in Aqueous Media - a Fluorescence Spectroscopic and Theoretical Study
The ground and excited state protonation of Coumarin 102 (C102), a fluorescent probe applied frequently in heterogeneous systems with an aqueous phase, has been studied in aqueous solutions by spectroscopic experiments and theoretical calculations. For the dissociation constant of the protonated form in the ground state, was obtained from the absorption spectra, for the excited state dissociation constant was obtained from the fluorescence spectra. These values were closely reproduced by theoretical calculations via a thermodynamic cycle – the value of also by calculations via the Förster cycle - using an implicit-explicit solvation model (polarized continuum model + addition of a solvent molecule). The theoretical calculations indicated that (i) in the ground state C102 occurs primarily as a hydrogen bonded water complex, with the oxo group as the binding site, (ii) this hydrogen bond becomes stronger upon excitation; (iii) in the ground state the amino nitrogen atom, in the excited state the carboxy oxygen atom is the protonation site. A comprehensive analysis of fluorescence decay data yielded the values kpr = 3.271010 M-1 s 1 for the rate constants of excited state protonation, and kdpr = 2.78108 s-1 for the rate constant of the reverse process (kpr and kdpr were treated as independent parameters). This, considering the relatively long fluorescence lifetimes of neutral C102 (6.02 ns) and its protonated form (3.06 ns) in aqueous media, means that a quasi-equilibrium state of excited state proton transfer is reached in strongly acidic solutions
Relationship Between Biogenic Amines and Free Amino Acid Contents of Wines and Musts from Alentejo (Portugal)
Rivaroxaban Compared with Standard Anticoagulants for the Treatment of Acute Venous Thromboembolism in Children: a Randomised, Controlled, Phase 3 Trial
Background: Treatment of venous thromboembolism in children is based on data obtained in adults with little direct documentation of its efficacy and safety in children. The aim of our study was to compare the efficacy and safety of rivaroxaban versus standard anticoagulants in children with venous thromboembolism. Methods: In a multicentre, parallel-group, open-label, randomised study, children (aged 0–17 years) attending 107 paediatric hospitals in 28 countries with documented acute venous thromboembolism who had started heparinisation were assigned (2:1) to bodyweight-adjusted rivaroxaban (tablets or suspension) in a 20-mg equivalent dose or standard anticoagulants (heparin or switched to vitamin K antagonist). Randomisation was stratified by age and venous thromboembolism site. The main treatment period was 3 months (1 month in children <2 years of age with catheter-related venous thromboembolism). The primary efficacy outcome, symptomatic recurrent venous thromboembolism (assessed by intention-to-treat), and the principal safety outcome, major or clinically relevant non-major bleeding (assessed in participants who received ≥1 dose), were centrally assessed by investigators who were unaware of treatment assignment. Repeat imaging was obtained at the end of the main treatment period and compared with baseline imaging tests. This trial is registered with ClinicalTrials.gov, number NCT02234843 and has been completed. Findings: From Nov 14, 2014, to Sept 28, 2018, 500 (96%) of the 520 children screened for eligibility were enrolled. After a median follow-up of 91 days (IQR 87–95) in children who had a study treatment period of 3 months (n=463) and 31 days (IQR 29–35) in children who had a study treatment period of 1 month (n=37), symptomatic recurrent venous thromboembolism occurred in four (1%) of 335 children receiving rivaroxaban and five (3%) of 165 receiving standard anticoagulants (hazard ratio [HR] 0·40, 95% CI 0·11–1·41). Repeat imaging showed an improved effect of rivaroxaban on thrombotic burden as compared with standard anticoagulants (p=0·012). Major or clinically relevant non-major bleeding in participants who received ≥1 dose occurred in ten (3%) of 329 children (all non-major) receiving rivaroxaban and in three (2%) of 162 children (two major and one non-major) receiving standard anticoagulants (HR 1·58, 95% CI 0·51–6·27). Absolute and relative efficacy and safety estimates of rivaroxaban versus standard anticoagulation estimates were similar to those in rivaroxaban studies in adults. There were no treatment-related deaths. Interpretation: In children with acute venous thromboembolism, treatment with rivaroxaban resulted in a similarly low recurrence risk and reduced thrombotic burden without increased bleeding, as compared with standard anticoagulants. Funding: Bayer AG and Janssen Research & Development. © 2020 Elsevier Ltd
Solvation and Protonation of Coumarin 102 in Aqueous Media: A Fluorescence Spectroscopic and Theoretical Study
Investigation of the Antioxidant Effect of Hungarian White Wines and Tokaj Wine Specialities
Authors investigated the antioxidant effect of wine-phenolics, expressed as total antioxidant status (TAS-value). This property may play an important role in elimination of the harmful effects of free radicals in human body.
Independently of their polyphenol composition, special quality Tokaj wines did not show extremely high TAS-values. In Tokaj Aszu wines the total antioxidant status was independent of the "puttony" number but was influenced by the length of aging time
Investigation of the Antioxidant Effect of Hungarian White Wines and Tokaj Wine Specialities
Authors investigated the antioxidant effect of wine-phenolics, expressed as total antioxidant status (TAS-value). This property may play an important role in elimination of the harmful effects of free radicals in human body.
Independently of their polyphenol composition, special quality Tokaj wines did not show extremely high TAS-values. In Tokaj Aszu wines the total antioxidant status was independent of the "puttony" number but was influenced by the length of aging time
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