Search results for "wine"
showing 10 items of 1468 documents
Effects of temperature, pH and sugar concentration on the growth parameters of Saccharomyces cerevisiae, S. kudriavzevii and their interspecific hybr…
2008
The effects of temperature, pH and sugar concentration (50% glucose + 50% fructose) on the growth parameters of Saccharomyces cerevisiae T73, S. kudriavzevii IFO 1802T and the hybrid strain S. cerevisiae × S. kudriavzevii W27 were studied by means of response surface methodology based in a central composite circumscribed design. Lag phase could not be properly modelled in the wine model system, where yeasts started the fermentation in few hours after inoculation. In the case of the maximum specific growth rate (μ max), the temperature was the most important variable for three yeasts, although the effects of sugar concentration (in T73 and W27) and pH (W27 and 1802) were also significan…
Description of the response of a new multi-parametric brain sensor to physiological and pathophysiological challenges in the cortex of juvenile pigs
2014
AIM Monitoring of intracranial pressure (ICP), local cerebral blood flow (CBF) and oxygen is part of modern intensive critical care medicine. Preclinical evaluation of newly developed catheters that should monitor several parameters simultaneously is reported poorly in the literature. The goal of our study was (1) to evaluate a new multi-parametric sensor in brain tissue and (2) to establish a testing protocol using pathophysiological challenges that target measured parameters of the sensor and autoregulatory boundaries and could be used as preclinical standard protocol in future studies. MATERIAL AND METHODS We describe data from 12 new multi-parametric brain sensors (MPBS) that were impla…
Sustainable viticulure in Brazil's context : a proposition
2015
The thesis involves the proposition of a framework for the sustainability of viticulture in Brazil using a territorial approach built from two exploratory studies in Brazilian wine regions of Campanha Gaúcha and Vale do São Francisco based on preliminary studies. Those studies involved technical visits in three countries (France, Italy and Spain) and frameworks’ observations in another five (South Africa, Australia, New Zealand, USA and Chile). The framework proposed is called BaccuS. It is structured on a matrix basis, with an axis corresponding to dimensions and other to guidelines, both in ascending order of complexity and development. There are eighteen topics that represent areas to ac…
Contribution à l'étude des « goûts de lumière » dans le vin de champagne *. 1. Aspects analytiques - Dosage des mercaptans et des thiols dans les vins
1977
<p style="text-align: justify;">Plusieurs accidents appelés « goûts de lumière » ou « goûts de réduit » ont été observés dans les vins de champagne au cours de ces dernières années. Dans ce travail, nous avons mis au point une méthode d'appréciation de ces goûts par dosage des groupements thiols ou mercaptans dans les vins. L'analyse comparative montre une bonne concordance entre la concentration en groupements thiols et l'appréciation gustative.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">For some years, accidents called « light tastes » or « reduced tastes » have been occured in Champagne wines; a method for thiols and mercaptans…
Diffusion of Oxygen through Cork Stopper: Is It a Knudsen or a Fickian Mechanism?
2014
International audience; The aim of this work is to identify which law governs oxygen transfer through cork: Knudsen or Fickian mechanism. This is important to better understand wine oxidation during post-bottling aging. Oxygen transfer through cork wafers is measured at 298 K using a manometric permeation technique. Depending on the mechanism, we can extract the transport coefficients. Increasing the initial pressure of oxygen from 50 to 800 hPa leads to a change in the values of the transport coefficients. This implies that oxygen transport through cork does not obey the Knudsen law. From these results, we conclude that the limiting step of oxygen transport through cork occurs in the cell …
Influence of lipid physical state on the in vitro digestibility of emulsified lipids.
2008
The objective of this study was to investigate the influence of the physical state of emulsified lipids on their in vitro digestibility by pancreatic lipase. A 10 wt % tripalmitin oil-in-water emulsion stabilized by sodium dodecyl sulfate (0.9 wt % SDS) was prepared at a temperature (>70 degrees C) above the melting point of the lipid phase (T(m) approximately 60 degrees C). A portion of this emulsion was cooled to a temperature (0 degrees C for 15 min) well below the crystallization temperature of the emulsified lipid (T(c) approximately 22 degrees C) and then warmed to 37 degrees C so as to have completely solid lipid particles. Another portion of the emulsion was directly cooled from 70 …
Sorption behavior of volatile phenols at the oak wood/wine interface in a model system.
2006
The sorption in a model system of aroma compounds of enological interest (mixture of the eight derivatives from guaiacol, 4-ethylphenol, and whiskylactone) onto wood was investigated to assess the influence of wood on the concentration of these volatiles during the aging of wine. To evaluate the influence of the solubility of aroma compounds in sorption phenomena, this parameter was determined for each volatile compound in model wine at 10 and 25 degrees C. The solubility is significantly higher in the model wine than in water and remains constant in the range of temperatures studied, except for guaiacol and vanillin. Kinetic and equilibrium sorptions were investigated. Sorption kinetics sh…
Effect of the natural winemaking process applied at industrial level on the microbiological and chemical characteristics of wine.
2013
The composition of yeast and lactic acid bacteria (LAB) communities and the chemical evolution of the large-scale commercial vinification of Catarratto IGT Sicilia, carried out under the biological regime, was followed from grape harvest until bottling. Simultaneously to the maximum growth of yeasts, LAB counts reached high level of concentration (6-7 log CFU mL(-1)) during the first steps of the alcoholic fermentation. Yeast identification was determined applying different molecular methods. The highest species biodiversity was observed on grape and must samples taken soon after pressing. Saccharomyces cerevisiae was detected at dominant concentrations during the entire winemaking process.…
Characterization of aged champagne wine aroma by GC-O and descriptive profile analyses
2000
Le but du travail est de caracteriser l'evolution de l'arome du champagne au cours du vieillissement et de comparer sous ce rapport le vieillissement accelere a 40 °C au vieillissement normal. Les methodes mises en oeuvre a cet effet sont l'analyse sensorielle, et les techniques GC-O et GC-MS. La representativite des extraits a ete etudiee au prealable par tests triangulaires et tests de similarite. Les profils descriptifs ont ete etablis par un panel d'experts sur des echantillons jeunes et vieillis. L'intensite des notes florale et fruitee diminue au cours du vieillissement, celles des notes boisee et d'evolution augmentent. On observe cependant des differences sensorielles entre les prod…
Mise en évidence d'une production de protéases exocellulaires par les levures au cours de la fermentation alcoolique du moût de raisin
1980
<p style="text-align: justify;">La durée d'activité très limitée dans le temps des protéases du raisin est confirmée en vinification en blanc, mais une nouvelle activité protéolytique peut être caractérisée à 37 °C et à pH 3,7 dans le moût au cours de la fermentation alcoolique.</p><p style="text-align: justify;">Cette activité doit être attribuée à des protéases exocellulaires libérées dans le milieu des levures. Parmi les souches essayées <em>S. bayanus</em> a une activité protéolytique plus importante que <em>S. cerevisiae</em>, ce qui se traduit par l'obtention de vins plus riches en azote soluble, donc plus stables du point de vue protéique et …