bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation expérimentale de « l'expérience tonneau ». Mesure des cinétiques d'imprégnation du liquide dans le bois et d'évaporation de surface
Authors: Feuillat François , Perrin Jean-René , Keller René , Aubert Danièle , Gelhaye Pierre , Houssement Claude , Perrin Jean , Michel Pierre
Published: September 2016

Un modèle expérimental miniaturisé a été conçu dans le but de simuler "l'interface tonneau". Les cinétiques de l'imprégnation du liquide dans le bois et de l'évaporation de surface ont été mesurées en conditions de cave (15°C ; 90 p. cent HR) pendant 200 jours sur des petits disques à orientation tangentielle (Ø 63 mm; épaisseur 9 mm) à l'aide d'une méthodologie spécifique. Ces résultats expérimentaux ont été obtenus sur 4 espèces traditionnellement employées en tonnellerie (Quercus robur L., Q. petraea Liebl., Castanea sativa Mill., Robinia pseudacacia L.).

L'analyse des cinétiques d'imprégnation et d'évaporation a permis de caractériser les régimes transitoire et permanent (état d'équilibre). Le régime transitoire est dominé par une forte imprégnation pendant les 40 premiers jours environ, qui décroît ensuite de façon asymptotique. Parallèlement, après un temps de latence appelé "retard à l'évaporation", le flux massique devient progressivement une fonction linéaire du temps. Le régime d'équilibre est atteint lorsque le niveau d'imprégnation de la pièce de bois est maximal et constant soit après 140 jours environ (profil d'humidité d'équilibre). Le fonctionnement en régime stationnaire se caractérise alors par un flux d'imprégnation à la face inteme équivalent au flux d'évaporation à la face exteme.

Les variations quantitatives des phénomènes sont apparues liées aux conditions de transfert externe (HR de l'air ambiant) et aux conditions de transfert interne (propriétés de la pièce de bois). La comparaison d'échantillons toutes conditions égales par ailleurs a ainsi montré des différences significatives de comportements vraisemblablement liées à la variabilité anatomique du bois (interspécifique, interindividuelle et intraarbre).

Cette variabilité pourrait avoir des conséquences sur les phénomènes oxydatifs et sur l'extraction des constituants du bois au cours de l'élevage des vins et des eaux-de-vie en fûts.
Influence of rootstock on volatile compounds of Vitis vinifera L. cultivar Italia. Preliminary results
Authors: Gómez-Plaza Encarnación , Martínez-Cutillas Adrián , Carreño Juan
Published: September 2016

This note presents the study of levels of total volatile compounds and monoterpene levels of Italia grapes grafted onto eight rootstocks as well as yield, soluble solids, berry weight and cluster weight, in order to determine if there is any difference in the aromatic composition of the berries. This study has been performed during one year in an Italian vineyard in Murcia (Spain).
Quelques composants volatils des vins de la région de l'Alpujarra-Contraviesa (Espagne)
Authors: Olalla Manuel , López María C. , Villalón Marina
Published: September 2016

Cette note rassemble les teneurs en substances volatiles des vins produits dans la région de l'Alpujarra-Contraviesa et située dans la province de Grenade ayant une tradition vitivinicole assez ancienne. Le caractère essentiellement traditionnel de l'élaboration de ces vins, leur distribution au détail et le manque de contrôle analytique nous ont poussé à déterminer les composés volatils les plus importants: les alcools, les aldéhydes et les esters.
Effet de polysaccharides sur la formation de trouble protéique dans un vin blanc
Authors: Pellerin Patrice , Waters Elizabeth , Brillouet Jean-Marc , Moutounet Michel
Published: September 2016

La découverte récente de deux polysaccharides, une mannoprotéine de levure et un arabinogalactane- protéine (AGP) de raisin, présents en très faible quantité dans le vin et ayant un effet protecteur contre la dénaturation thermique des protéines, permet d'envisager l'obtention de vins stables sans recourir à l'élimination des protéines par collage à la bentonite. 15 polysaccharides aux compositions et structures variées ont été testés, mais sont pour la plupart sans effet ou bien provoquent une forte augmentation du trouble après passage du vin à la chaleur. Une activité protectrice des protéines a cependant été observée avec un AGP mineur de pomme et une gomme d'Acacia senegal.

L'utilisation de ces polysaccharides actifs pour la stabilisation protéique des vins blancs passe par une meilleure compréhension de leur mode d'action ainsi que par l'augmentation de leur concentration dans les vins.
Evaluation instrumentale de la couleur
Authors: Piracci Antonio
Published: September 2016

On se réfère à la mesure conventionnelle de la couleur par l'emploi de la méthode de la Commission Internationale de l'Éclairage (C.I.E.), on décrit la détermination des coordonnées chromatiques et des paramètres (nuance, luminosité, pureté de la couleur) qui caractérisent la couleur des vins.

En se servant d'une interprétation géométrique sur le diagramme chromatique C.I.E on obtient des équations qui fournissent des résultats plus précis de ceux qu'on obtient normalement par l'interpolation graphique. En outre un programme pour PC en langage BASIC est présent, par lequel, d'après les lectures des absorbances du vin, on obtient immédiatement et rigoureusement les valeurs chromatiques.

Les distances entre les points de couleur, obtenus par la méthode C.I.E « intégrale » (40 mesures d'absorbances) et par d'autres méthodes simplifiées (4 ou 13 absorbances), sont comparées au seuil de sensibilité à la variation d'une couleur déterminée et on obtient des suggestions qui imposent des circonspections à propos de l'usage des méthodes simplifiées.
Dosage fluorimétrique de l'acétoïne dans le vin
Authors: Voulgaropoulos Anastasios N. , Soulis Th.
Published: September 2016

Les auteurs proposent une technique analytique de dosage de l'acétoïne dans les vins après oxydation en diacétyle et condensation de ce dernier avec le diamineanisol-3,4. Le produit de condensation émet une forte fluorescence à partir de laquelle on peut calculer la concentration de l'acétoïne dans le vin. La méthode proposée est simple, sensible, fiable et spécifique.
Estimation du degré de polymérisation des procyanidines du raisin et du vin par la méthode au ρ-dimethylaminocinnamaldéhyde
Authors: Vivas Nicolás , Glories Yves , Lagune Laure , Cédric Saucier , Augustin Monique
Published: September 2016

Les auteurs proposent une nouvelle technique d'estimation du degré de polymérisation des tanins du raisin et du vin, utilisant un aldéhyde spécifique des structures phénoliques renfermant des noyaux phloroglucinols ; la ρ-dimethylaminocinnamaldéhyde (DMACH). Cet aldéhyde est utilisé pour la première fois pour la détermination du degré de condensation des procyanidines. L'indice obtenu avec cet aldéhyde est d'autant plus faible que le degré de polymérisation des tanins est élevé. Le protocole retenu permet de réaliser des mesures avec un coefficient de répétabilité moyen de 5 p. cent (au seuil de confiance α = 95 p. cent). La méthode permet, d'une part d'estimer le degré de polymérisation moyen des procyanidines et d'autre part de mesurer l'influence de certaines pratiques (consommation de l'oxygène dissous, ajout d'acetaldéhyde, supplémentation en extrait phénolique) sur la variation du degré de condensation moyen des tanins.
The principal ecogeographical groups in French grapevines assortment
Authors: Bisson Jean
Published: September 2016

The natural french grapevine varieties assortment has been reduced during the recent years because of many factors, principally the post-phylloxeric reconstitution, the rationalisation of the production and the varietal and clonal selections.

Before a still more important reduction is to be made it is necessary to give a classification of french autochton cultivars based on ecogeographical groups or sortotypes.

These works keep classic genetic interest in possible crossings : less inbreeding, more heterosis.

Besides they enable a better approach of modern classifications based on biochemistry or atomic physics, pigments, enzymes, tracers, and so on, so as to confirm or infirm botanic results.
Characterization of the region and year of production of wines by stable isotopes and elemental analyses
Authors: Day M. , Zhang Ben Li , Martin Gérard J. , Asselin Christian , Morlat René
Published: September 2016

Stable isotope and elemental analyses were applied to the study of wines produced from the Cabernet Franc vine variety cultivated during several years (1982 to 1990) on specific parts of the Saumur-Champigny vineyard dedicated to the « terroir » experiment of INRA. The purpose of this work was to describe the behaviour or 2H, 13C and 18O isotopes in the water and ethanol of wines in terms of the meteorological conditions (temperature, precipitation and insolation) which govern vine growing. Since the « terroir » concept involves a synergy between the c1imate and the soil, the distribution of typical metallic elements was also determined by flame and electrothermal ionization atomic absorption. About twenty parcels, carefully described from the geological and pedological point of view were considered in this study which demonstrated the ability of Sr, Al and Rb to discriminate between wines from the same year but grown on adjacent parcels. The content in trace elements of the wines was also shown to be correlated with the geological nature of the soil. As far as stable isotopes are considered, it appears that the climate of the year of production of a given region has a drastic influence on the isotope ratios of water and ethanol of wines and good correlations way be computed between these parameters and temperature and precipitations. From a more basic aspect, it is also shown that the nature of the soil which governs, at least in a part, the water use efficiency of vine, induces typical variations in the isotopic composition of wines. The results of this study demonstrate also the ability of stable isotope and elemental analyses to determine the geographical origin of a wine, and when the region of production is known, to infer the year of production from meteorological data. This method might prove to be an alternative method to radio carbon analysis for the next vintages.
The effect of training system and cultivar on the rate of leaf appearance of the grapevine (Vitis vinifera L.)
Authors: Palchetti C. , Gozzini Bernardo , Miglietta Francesco , Orlandini Simone
Published: September 2016

The rate of leaf appearance was compared in two grapevine (Vitis vinifera L.) varieties (Sangiovese and Cabernet-Sauvignon) and in three different short pruning training systems (traditional cordon, single curtain and vertical cordon pruned). Results showed that there was no significant effect of training systems on leaf appearance. There was instead a significant effect of cultivar that suggested a different adaptive response of cultivars to climates they were selected for. A recently published simulation model of leaf appearance in grapevine was used to interpretate these differences.
Mineral vine nutrition in Galicia (NW Spain)
Authors: Garcia-Rodeja Gayoso Eduardo , Rodriguez Lovelle Begoña
Published: September 2016

Mineral nutrition of two local cultivars of Galicia viticultural district (NW Spain) was examined. Two cultivars, Merenzao (red) and Godello (white), were grown on different soil conditions and both were grafted on 3309, 420A, 161.49, Rupestris du Lot, 4IB, SA, ll0R and 196.17; Godello was also grafted on 99R. The influence of rootstock and c1imatic annual conditions on N, P, K, Ca and Mg contents of leaf petiole and blade were studied. The rootstock's effect was observed for every nutrients on the two vineyards, while c1imatic conditions (rather water availability) influenced the nutrition of vine growing on the most difficult pedological conditions.
Gynaecium ontogenesis of Vitis vinifera L. var. Chardonnay in closed connection with the apparition of tannic vacuoles
Authors: Fougère-Rifot Monique , Benharbit EL Alami Naïma , Brun Olivier , Bouard Jacques
Published: September 2016

Gynaecium ontogenesis of Vitis vinifera L. var. Chardonnay is followed up stage by stage. It is divided into twenty stages from initial meristem at the top of pedicel till just after the fruit is set. Each stage is morphologically and cytologically investigated. Special features of the female gametophyte are made conspicuous. In the ovary, the origin of fruit septum, the pathway of pollen tubes in the style and in the septum are revealed. A close connection between the presence of vacuolar tannins in gynaecium and especially in ovule and the ovule vitality is reported. The absence of vacuolar tannins is a symptom of illness and premature breakdown of the ovules before their transformation into pips. The whole ontogenesis is summed up in a very full table.
Bibliographic study of potentiometric methods of wine and must analysis
Authors: Pérez-Olmos Ricardo , Herrero R. , Lima José L.F.C. , Lopes T. I.M.S. , Rangel António Osmaro Santos Silva
Published: September 2016

In this paper, an overview of the application of potentiometry to wine and must analysis is presented. The large number of electrodes nowadays available with good characteristics for routine use, namely good selectivity and low response times, allowing measurements in a broad linear dependence range, with a relative low cost, simple sample pre-treatrnent requirements, no sensitivity to colour or turbidity of the samples, make potentiometry an attractive instrumental technique for wine and must analysis. Methods developed so far present good precision and the results show a fairly good agreement with those obtained by the application of reference methods.
Principal volatil components of Txakoli of Bizkaia
Authors: Escobal Ana , Iriondo Carmen , Laborra Concepción
Published: September 2016

The aim of this work was to characterize the Txakoli of Bizkaia, a wine produced in the Basque Country. This note gives account of the volatile content of the wine which has been awarded by the Denominacíon de Origen Bizkaiko Txakolina quality label (BOPV, 1994).
Plastids, starch and chlorophyll in Vitis vinifera L. berry during its ontogenesis
Authors: Fougère-Rifot Monique , Park H.-S. , Cherrad Monique , Darné Gérard , Bouard Jacques
Published: September 2016

Structural and ultrastructural investigations on plastidial ontogenesis in the tissues of Vitis vinifera berry arc realised in narrow association with starch and chlorophyll dosages from the stage of fruit setting till berry ripeness. During the whole of that period, some chloroplasts, starch and chlorophyll arc noted in grape berry.

Well developed starch chloroplasts and a great deal of chlorophyll are present in herbaceous stage of berry development. A large starch content perhaps seems to show that berries arc involved in their own glucides synthesis during this stage.

After that, during ripening stage, chlorophyll content strongly decreases and soluble glucides that accumulate in the berry are essentially derived from leaves.
A S-cysteine conjugate, precursor of aroma of White Sauvignon
Authors: Tominaga Takatoshi , Masneuf-Pomarède Isabelle , Dubourdieu Denis
Published: September 2016

4-mercapto-4-methylpentan-2-one (4-MMP), a strongly odorant compound responsible for the « boxtree » or « broom plant » odour of the Sauvignon wines, can be enzymaticaly released in vitro from an odourless must extract. The enzyme source used is a cell-free extract of the gastrointestinal bacterium Eubacterium limosum. This crude preparation exhibits a cysteine β-lyase activity which requires the presence of pyridoxal phosphate. The release of 4-MMP is inhibited when the substrate is previously treated with N-hydroxysuccimide acetate which reacts with a primary amine. The same bacterial extract is also able to release 4-MMP, pyruvic acid and ammonium, from S-(4-méthylpentan-2-one)-L-cysteine. On the other hand, the cleavage of S-(4-méthylpentan-2-one)D,L-homocysteine and S-(4-méthylpentan-2-one)- glutathione is very limited. These results suggest that the precursor of 4-MMP in Sauvignon must is a S-cysteine conjugate. Such an aroma precursor in grapes or in other fruits has never been round berore.
Genetic determination of Saccharomyces cerevisiae et Saccharomyces bayanus species by PCR/RFLP analysis of the MET2 gene
Authors: Masneuf-Pomarède Isabelle , Aigle Michel , Dubourdieu Denis
Published: September 2016

Several yeast strains of the species S. cerevisiae, S. bayanus and S. paradoxus, first identified by hybridization experiments and DNA/DNA hybridization were characterized by using Polymerase Chain Reaction/Restriction Fragment Length Polymorphism (PCR/RFLP) of the MET2 gene. The concordance between this tool and classical genetic analyses did not reveal any exception for all the strains analysed, so PCR/RFLP of the MET2 gene proves to be a reliable and fast tool for delimiting S. cerevisiae and S. bayanus. OEnological strains race bayanus, chevalieri, capensis gave S. cerevisiae restriction patterns, whereas most of strains race S. uvarum belong to S. bayanus and displayed a specific chromosomal band patterns different from band patterns of S. cerevisiae strains. To avoid confusion in oenological terminology, oenologists should no longer use the name of bayanus to designate industrial or wild S. cerevisiae Gal- strains, and should consider S. bayanus as a distinct species.
Analysis of cis- and trans-resveratrol in Portuguese wines
Authors: De Revel Gilles , Hogg Tim , Santos Cristina
Published: September 2016

Trans-resveratrol (trans-3,5,4'-trihydroxystilbene) has been reported as contributing to the health promoting properties of wine. In this study wines made exclusively from native Portuguese varieties were assayed for the levels of trans-resveratrol. The method developed uses GC-FID and GC-MS determinations of TMS derivatives; derivatisation by hexamethyldisilazane following ether extraction of wines. Two currently used food antioxydants nordihydroguaiaretic acid (NDGA) and 2' ,4' ,5' -trihydroxybutyrophenone (THBP), were employed as internai standards, being extracted and derivatised in exactly the same way as the determined resveratrol. These internal standards permitted the verification of a good linearity and reproducibility for this determination, with a detection limit of 5 μg/l. A characteristic of this method is the enhanced discrimination between cis- and trans- isomers of resveratrol with the consequent possibility of the determination of cis-resveratrol. The levels of resveratrol from wines of different regions of Portugal was studied. There appeared to be considerable variation in the concentrations encountered in the various wines although generally red wines contained much higher levels than white wines. The use of glucosidase enzymes in winemaking led to an increase of 3 - to 4 - fold in the levels of resveratrol encountered in Vinho Verde wines. Differences were noted between the resveratrol levels of specifie varietal wines from the Vinho Verde.
Comparison of pectolytic and proteolytic activities of six clarifying commercial preparations. Incidence of secondary enzymatic activities on proteins in Champagne musts
Authors: Berthier Laurent , Marchal Richard , Maujean Alain
Published: September 2016

In order ta estimate c1arifying aptitude and the effects of prefermentation treatment by commercial pectinases, polygalacturonase (PG), pectin Iyase (PL), pectinmethylesterase (PME) and proteolytic activities of six pectinases samples were studied. PG activity is preponderate and proportional to the relative protein concentration.

These one, submitted to both SDS-PAGE and isoelectric focusing technics, show molecular weights ranging from 20 ta 100 kDa and isoelectric points ranging from 3.00 ta 7.40. Total protein of Champagne grape varieties Chardonnay (CH) and Pinot noir (PN) - were submitted to an isoelectric focusing. All of the pI's ranging from 3.30 to 4.55 (CH) and from 3.30 to 4.90 (PN). Proteases are put in evidence in commercial pectinases using fluorescamine- casein as substrate. However, they seem to have no incidence upon must proteins.
Dispersal of marked and released Lobesia botrana in a small isolated vineyard and the effect of synthetic sex pheromone on moth movement
Authors: Schmitz Vincent , Roehrich Roger , Stöckel Jacques P.
Published: September 2016

Mobility of moths at the time of implementation of the mating disruption method, against Lobesia botrana, requires to maintain, around the vineyards a border area. Its width depends of the dispersal ability of egg laying females. This dispersal was studied by use of the « mark release capture » insect technique. Laboratory reared insects were colored externally or internally and released in the middle of a food trap network. A small surface around one release station was equiped with pheromone dispensers. Two main results for setting up the insect control were established : 1 - the virgin females were not very mobile and were only captured in low numbers by the food traps. Consequently it is impossible to use this trapping technique to evaluate the sucess of mating disruption and the hypothesis that females leave the vineyard impregnated with pheromone in order to be inseminated outside is improbable. 2 - the dispersal of females within the vineyard exceeds rarely 80 m. This value seems to define width of the protection area around the vineyards treated by the mating disruption technique, that are close to other highly infested vineyards.
Effect of certain clarification treatments on some components of red wine composition
Authors: García Maria José , Aleixandre José Luis , Sanz Jesús
Published: September 2016

Many authors have worked on wine clarification pointing out the advantages that it has to obtain limpid and bright wines as the consumer requires nowadays. In this work, we study the influence of the clarification done with different doses on the main polyphenols, organic acids and poliols of the Monastrell red wines made by the system of continuous vinification in the Monovar cooperative cellar from Denomination of Origin Alicante (Spain). After fermentation and after decanting, the wine was clarified in 100 litres tanks. Five different clarifiers have been used with three different doses in each one. Two days after the treatment, the wines were filtered on the earth and were then submitted to -5° for one week to eliminate the bitartrate. They were filtered over plates when the treatment was finished. Finally, before bottling they were subjected to a sterile filtration.The results show that the clarification lowers the coloring intensity up to 27 p. cent. The higher the dose, the higher the decrease. As for the shade, we noticed that there is a slight increase in each clarificated wine. The tannin content decreases up to 20 p. cent for high and average doses of casein. The treatments used lower the content in anthocyans from 5 p. cent (for lower doses of casein) to 19 p. cent (for higher doses of bentonite). As for the acids, the tartaric acid decreases with the quantity of clarifiers, the malic acid hardly changes with the treatment, the same happens with the lactic acid. For the citric acid, there is a small decrease with the clarification. The contents of glycerol decrease in all the wines, whatever clarifier is used. The contents in 2,3- butanediol of the wines hardly change with the claritication.
Determination of the content of dimethyl sulphide in some red wines
Authors: Anocibar Beloqui A. , Kotseridis Yorgos , Bertrand Alain
Published: September 2016

This note presents a newly developed assay method of the dimethyl sulphide, and the assay of this compound in various red wines of Bordeaux and Greece, in order to determine its possible organoleptic impact.
Attemps to improve the grape seed germination
Authors: De Wilde A. , Darné Gérard
Published: September 2016

Using the« standard» germination method (dehydration, hydration before conserving at 5°C during several weeks or several months and rehydration followed by the germination at 27°C/28°C), it is possible to conserve grape seeds of Vitis vinifera c.v. Ugni blanc more than one year and preserve a high ability of germination. However, to be able to work on young seedlings rapidly after harvesting, this method requiring a too long breaking dormancy treatment (conserving at 5°C), we tried to change these treatments and to speed up the breaking dormancy using an anoxic treatment finalized at the laboratory. Even if this system does not allow to obtain the best rate of germination, it aIlows to save 50 days for Ugni blanc treatment and more than 150 days for Merlot avoiding breaking dormancy with cold treatment. To improve the grape seed ability of germination following the « standard» method, we used a solution of etephon in external supply, releasing ethylene in tissues. Seeds conserved 90 days at 5°C and hydrated with this solution have a better rate of germination (+ 10 p. cent in comparison with a standard sample treated with the same method without ethylene). Finally, non conserved at 5°C grape seed lyophilization can be a rapid method for breaking dormancy and improving (at least 40 p. cent) the ability of germination.
Qualitative and quantitative study of interaction between Saccharomyces cerevisiae and Leuconostoc oenos
Authors: Gilis Jean-François , Strehaiano Pierre , Délia Marie-Line
Published: September 2016

Weak malolactic fermentations in wine making are often attributed to the medium constituents such as ethanol and SO2. However, some authors report that the interactions between Saccharomyces cerevisiae and Leuconostoc oenos could be responsible too.

The aim of this work is to characterize the influence of S. cerevisiae on the growth of L. oenos. First, a qualitative study was performed on solid medium containing 8 g/l of L-malic acid. In this case, L. oenas was mixed to M.R.S agar and poured into Petri plate, then S. cerevisiae was seeded in rings on the agar surface. After incubation, the coculture result in an inhibition of L. oenos growth by S. cerevisiae.

In order to quantify this phenomenon, a culture of L. oenas was carried out on liquid medium prefermented by S. cerevisiae (supplied with M.R.S nutrients) and was compared with a control on M.R.S medium. Both contained 8 g/l of L-malic acid. This technique allows to separate the microorganisms in order to avoid competitions between the strains.

The prefermented medium affects L. oenos growth and the malolactic fermentation, but the results depended on the pH and the temperature. Globally, low pH (3,4) and high temperature (30°C) conditions increased the inhibitory effect of the prefermented medium. This medium contains inhibitory molecules for L. oenas. In agreement with some authors, those molecules could be the medium chain fatty acids (C8 to C12) released in the medium by S. cerevisiae because of their pH-dependent toxicity. However, those results may be different with other couples of strains of S. cerevisiae and L. oenos.
The malolactic fermentation in the wines of Naoussa (Greece). Study of lactic acid bacteria
Authors: Soufleros Evangelos H. , Konstantinidis N. , Tsitsanopoulou Elefteria , Gerakiannakis G.
Published: September 2016

The red wine« Appellation d'Origine Naoussa de qualité supérieure » stemming from the « Xynomavro » vine cultivated in this wine-growing region of western Macedonia (Greece) needs the advantages coming of malolatic fermentation. This wine, in spite of its incontestable qualities has a strong astringent and a high level of acidity, the malic acid contributing essentially to these two characters.

Because of the interest malolactic fermentation presents for this region, we have collaborated with the wine-producters to insure, at first, the generally admitted conditions which favour the evolution of malolactic fermentation, then to study it.

The latter includes : a) the control of the conversion of malic acid into lactic acid by chromatography paper and b) the enumeration, isolation and identification of lactic acid bacteria.

During this two-year-long research, 187 samples have been taken from 50 different tanks during 12 samplings. The isolation of lactic acid bacteria was done by plating dilutions of wine samples and their identification with the API system and other physico-chemical and enzymatic methods.

Data processing has been done by computer and given a strain group distribution according to their similarity.

The results show that the homofermentative lactic acid bacteria - mainly Lactobacillus plantarum - are more numerous than the heterofermentative ones before the malolactic fermentation. They decrease during the fermentative process and disappear with its completion.

The heterofermentative lactic aeid baeteria, whose main specie is Leuconostoc oenos evolves inversely.

A low increase of Pediococcus has been observed too after the beginning of malolactic fermentation. A statistical analysis confirms the main points of this research.

The application of malolactic fermentation becomes more efficient the second year; it is favoured in press-wines and for temperatures kept at 20-25°C; the bacteria population is also increased.

The persued reduction of total acidity in wines, which underwent malolactic fermentation, was considerable.
Practical application of immunofluorescence for the detection of bacterial contaminants during vinification
Authors: Bouix Marielle , Busson Claire , Charpentier Monique , Leveau Jean-Yves , Duteurtre Bruno
Published: September 2016

This study presents a rapid and specific microscopie technique for detecting and identifying populations of lactic acid bacteria in musts, wines, and inoculum starter cultures. Through the use of fluorescent antibodies, this procedure can be performed in less than two hours, and it is effective with Leuconostoc, Pediococcus and Lactobacillus concentrations as small as 102 cells/ml. Implementation of this technique will assist winemakers in controlling malolactic fermentations and in preventing lactic acid bacterial spoilage.
Differentiation of local climate in the Alsatian vineyard
Authors: Dumas Vincent , Lebon Eric , Morlat René
Published: September 2016

Climatic and soil characteristics are the main factors affecting the qualitive potential of a vineyard. At the scale of a « terroir », it is important to know the variability of the local climate (mesoclimate). Therefore, we studied landscape parameters (altitude, slope, etc.) affecting the local c1imate of vineyards in Alsace (NE FRANCE), at six sites each representative of a« terroir» type during 1991,1992 and 1993. Climatic variables were measured hourly and daily throughout the growing season (April - September).

Wind speed was the climatic variable which was most affected by the landscape. The angle of opening of the landscape, its altitude and its orientation are the main factors differentiating the terroirs which were compared.

The variabiliy of global solar radiation depends on the slope, the orientation and the height of and distance to topographics elements. This variability depends on solar angle and is smallest in June.

We observed small differences for average seasonal temperature between sites. On the other hand, more detailed studies considering different daily weather conditions (cloudy versus clear weather) and measures per hour and day contributed to a better differentiation between sites. In cloudy weather conditions, temperatures depended on altitude only (thermic gradient -O,6°C/100 m). In clear weather conditions, night temperatures depended on the altitude and the slope of the site; day temperatures were also influenced by the orientation, and the angle of opening of the landscape and the characteristics of the soil surface.
First result of tartaric stabilization by adding mannoproteins (Mannostab™)
Authors: Moine-Ledoux Virginie , Perrin A. , Paladin I. , Dubourdieu Denis
Published: September 2016

Some mannoproteins which are extracted by enzymatic hydrolysis of yeast's cell wall with the aid of commercial preparation composed with beta-glucanases (Glucanex™) inhihits the tartaric acid's salt breakdown in model solution as well as in wines for an addition between 10 and 25 g/hl. On the other hand, heat extracted mannoproteins arc inactive on the tartaric precipitation stabilization. Furthermore, the crystallization inhibitor activity of the enzymatic extracted mannoproteins is due to the presence of sharply glycosylated mannoproteins of mediummolecular weight (30 to 50 kda) which are not heat extracted. That is why the heat extracted mannoproteins are inactive. The enzymatic extracted mannoproteins are produced at a pilot plan. This preparation (Mannostab™), soluble in wines, colourless and without any flavour, stabilize with the same efficiency than a freeze treatment and this effective live is superior to the metatartric acid. Moreover, the necessary steps were been taked to permit experimentally this new product : Mannostab™
Discrimination of wines from the Mercosul countries according to their mineral composition
Authors: Rizzon Luiz Antenor , Miele Alberto , Rosier Jean-Pierre
Published: September 2016

The chemical and sensory characteristics of wines are related to the natural factors of their viticultural areas. The existing soil and climate diversity of the Mercosul countries is favorable to the elaboration of wines with different chemical composition. The mineral elements have already been studied to characterize wines from several viticultural regions all over the world. But the discrimination of wines from the Mercosul countries according to their mineral composition has not been done yet. The objective of this work was to characterize wines from Argentina, Brazil and Uruguay according to their mineral composition. Thirty-one wines were analyzed: 11 were from Argentina, 10 from Brazil and 10 from Uruguay; in relation to the type of wine, 10 were white, 11 rosé and 11 red ones. The analyses were made through the atomic absorption spectrophotometry; flame emission spectrophotometry; and colorimetry. The principal component analysis showed that the axes 1,2 and 3 explained 38.6%, 28.2% and 10.4% of the total variation. The principal component analysis made it possible to discriminate the wines from these three countries apart. The mineral elements which showed the highest discriminant effect were Li, Mg, P, K, Rb, Na, Mn and Fe. The Argentinian wines showed higher contents of minerals, specially the Li, Na, Mg and P; the Brazilian ones had higher levels of Rb and Mn; the Uruguayan wines showed an intermediary composition.
Application of the multidimensional analysis to the differentiation of Spanish white wines
Authors: Álvarez Inmaculada , Casp Ana , Zunica L. , Aleixandre José Luis , García Maria José
Published: September 2016

The modern enology technology allows the elaboration of high quality wines that preserve the differentiating characteristics according to the vine, production area, fermentative yeasts or to the different technology used for the elaboration of wine.

The study of 45 spanish white wines with « Denomination of Origin », 5 of those belong to Alto Turia, 6 to the Clariano, 14 to the Valentino, 10 to the Valdepeñas and 10 to the Rueda, allows to establish importants differences among them according to their chemical composition. This differentiation has been possible by means of the application of the Discriminant Analysis to 35 parameters related with the chemical composition of theses wines. In the first place these compounds have been grouped, according to their chemical affinity, in three groups: general component, alcohols and esters. Discriminant Analysis has been applied to each one of these groups, being observed that the esters allow to be carried out the classification of these wines in their corresponding groups, because only it confuses some wine of Clariano with those of Valentino.

To carry out a correct classification of 45 wines studied in their corresponding « Denomination of Origin », it is necessary to appeal to carry out a Discriminant Analysis with the 35 compounds together, being, in this case, the compounds that contribute to this differentiation pratically the same ones that those which contribued to differentiate each group of variables separately.
Effects of flusilazole, a sterol biosynthesis inhibitor fungicide, on the free and bound aroma fraction of Muscat of Alexandria wines
Authors: Aubert Christophe , Baumes Raymond L. , Günata Ziya , Lepoutre Jean-Paul , Cooper Jean-François , Bayonove Claude L.
Published: September 2016

Vines from Muscat of Alexandria cultivar were subjected to flusilazole treatments, a sterol biosynthesis inhibitor fungicide (SBI), over 2 years. Effects of these treatments on the corresponding wines were assessed by analyzing the free and bound aroma fractions using selective retention on Amberlite XAD-2 and gas chromatography-mass spectrometry. Quantitative changes in the composition of the free and bound fractions of the treated wines were observed. Levels of varietal, prefermentative and fermentative compounds were moditied and a regulatory mechanism for sterol synthesis in yeast involving the monoterpenes could be hypothesized.
Gas chromatographic quantitative analysis of the gaseous emissions and carbon balance in the alcoholic fermentation
Authors: Chon C. , Poulard Alain , Rabiller Claude
Published: September 2016

The balance of the carbon transfers occuring during the fermentation of sugar is still poorly defined. To our knowledge, no description exists which accounts at each moment of the process for the components in the liquid phase and the evolution of the gaseous carbon components. However, this question is of prime importance for the vinification process. The gap between the concentration of fermentable sugars in a must and the theoritical potential alcoholic degree is always significant. The same is true for chaptalisation, in which vinters generally use more sugar than needed to obtain a given alcoholic degree. In both cases, the question is : what happens to the carbon matter lost? Is it transformed into liquid and/or gaseous metabolites or simply evaporated as ethanol or as other volatile components?

ln order to try to answer to this question, methods able to analyse simultaneously and quantitatively the liquid phase, the gaseous emissions and the biomass are needed. Recently, we have shown that under suitable defined conditions 13C NMR spectroscopy allows the quantitative measurement of at least eight components present at a concentration up to 5 x 10-3M (glycerol, glucose, butandiols, tartric, malic, lactic, citric and succinic acids) in a short time (one hour) with a precision of about 3 p. cent. The measurements of the ethanol concentrations and of the amount of carbon transferred in the biomass are easily achieved using respectively ebullioscopic and standard combustion techniques. We are now able to extend these results and to show that, by using gas chromatography in a continuous dynamic mode and under a sweep of air at the head space of the fermentor, it is possible to measure quantitatively the mixture of volatile substances (composed mainly of air, carbon dioxide, ethanol and water) emanating from an alcoholic fermentation. The results obtained, when correlated with quantitative 13C NMR spectroscopy on the medium components permits the total balance sheet of the carbon transfers occuring during the fermentation process betwcen the liquid and the gaseous phases to be established. Our results indicate that the losses of ethanol during the fermentation process conducted under an air flow at the head space of the fermentor, may reach about 10 p. cent of the theoretical maximal amount of ethanol produced. The experiments presented here could explain the ethanol losses observed during some vinification processes conducted in open tanks.
First results about use of a possible substitution product for sulfur dioxide in wine making
Authors: Marcillaud Laurence , Donèche Bernard
Published: September 2016

Plant extract DF100, produced by Chemie Research and Manufacturing Co. (Casselberry, Florida-U.S.A.) from wastes of grapefruit (Citrus paradisi sp.) juice elaboration, presents anti-microbial and anti-oxydant properties. First experiments to use it to substitute sulfur dioxide in wine-making have been realized during two years.

When DF100 is added in must at low level (less than 1 g/l), it does not influence growth and activity of yeasts.

Wines obtained only differ on several fermentation secondary products as propanediol. This compound is all-ways more produced in the presence of DF100.

Phenolic composition of red wines is weakly modified. Lowest anthocyanin extraction is balanced by a greater color, resulting from a higher ionization degree without sulfur dioxide.

Plant extract ensures a good protective effect against bacterial alterations during wine ageing in wood casks.

For highest concentrations, especially for stopping fermentation to obtain natural sweet white wines, plant extract leads to organoleptic deviations in color and taste.

lt is necessary to follow study on this plant extract and to develop new preparation with a more purified and colourless product, hoping that toxicological studies will demonstrate its harmlessness.
Acids and buffers in wine
Authors: Höchli Ulrich
Published: September 2016

A complete set of physico-chemical equations governing the interaction between acids and buffers is established. Together with formulae describing transformations of acids by biochemical reactions, these equations are used to monitor acid and buffer content during vinification. Several data sets from different wineries are used to test the validity of the approach.
Composition and content of fatty acids in Vitis vinifera L. var. Cabernet Sauvignon leaves infected with the eutypiosis fungus, Eutypa lata
Authors: Koussa Tayeb , Cherrad Monique , Zaoui Driss , Broquedis Michel
Published: September 2016

On Cabernet sauvignon, eutypiosis sensible variety, we have compared fatty acids content in healthy Jeaves (S: leaves beared by healthy vine stock), in leaves seeming healthy (Ap.S: leaves beared by arm without symptoms, the other arm is diseased) and in diseased leaves (M: leaves beared by diseased arm). The results show that disease does not alter the fatty acids order. Linolenic acid (CI 8:3) content is always the most important, followed by palmitic (CI6:0) and Iinoleic acids, then by stearic (CI8:0) and oleic acids and at last by arachidic acid (C20:0). During the three stages studied (flowers buds: H, flowering: I and closed cluster: L), only the development of CI 8:3 content was modified by disease. It increases in healthy leaves at stage I, while in Ap.S and M leaves there is a decrease from H to L stages. Otherwise, development of fatty acids proportions does not seem to be changed by eutypiosis.

Proportions and content comparison in S, Ap.S and M leaves show a decrease of C 18:3 synthesis benefit of C 18:2.

This increases is important as well as the symptoms are evident. These results seem to be in relationship with decrease of leaves size caused by eutypiosis. At the end, the disease induces a desaturation decrease of C18:0 and C18:2 as well as an aliphatic chain lengthening of C16:0. These inhibitions are showed by more increase of CI 6:0 and CI 8:2 in diseased leaves than in healthy leaves. No action is observed in CI 8: 1 desaturation.
Influence of nitrogen fertilization on Vitis vinifera cv. Merlot with permanent grass cover. (Nitrogen content, nature and concentration levels of some amino acids of musts and wines)
Authors: Larchevêque Corine , Casanova A. , Dupuch Vincent , Renard Romain
Published: September 2016

Since 1995, it has heen running an experiment on the introduction of nitrogen fertilization on permanent grass cover. This has been done in order to determine both the role and the influence of nitrogen on the fermentability of the must. Located south of Saint-Emilion, the plot area studied has a regular, sandy, clayey soil 60 centimeters deep. The cultivar Merlot is grafted on the Riparia Gloire from Montpellier rootstock. Five N- fertilizations were compared : T (0 kg N/ha/year), A (30 kg N/ha/year), 8 (60 kg N/ha/year), C ( 90 kg N/ha/year), and D (45 kg N/ha at springtime and 45 kg N/ha at flowering period). For the different N-fertilizations, the numher of clusters per vine was the same for the two experimental years. The mean cluster weight allowed for evaluating the nitrogen effect on the yield. Nitrogen fertilization on the permanent grass cover in the vineyard depends upon climatic conditions in the spring and, more specifically, upon the rainfall pattern. Varietal vigor can he increased or decreased with the level of nitrogen. However, in all cases studied, late contribution of nitrogen was found to he harmful. In fact, most nitrogen added at springtime was used by the grass cover and the competitiveness of the latter was increased. Only test « C » proved to be adequate to satisfy both vineyard and grass cover needs (this is shown in the study of the pruning wood weight variation compared to the standard « T»). The duration of alcoholic fermentation is quite closely correlated to the content of nitrogen composites in the must and more particularly in amino acids. The global amino acid contents of musts and wines were higher in 1996 than in 1995, but in this last case more numerous kinds of amino acids were present. However, for both years studied, proline represented at least 50 percent of the global amino acids content. A statistical analysis on the five N-fertilizations showed a clear differentiation between the two vintages studied ; that is to say, each vintage was identified by specific amino acid profiles. This « vintage » effect was proved by tasting results.
Behaviour of the Cabernet Franc grapevine variety in various « terroirs » of the Loire Valley. Influence of the precocity on the composition of the harvested grapes for a normal climatic year (example of the year 1988)
Authors: Barbeau Gérard , Morlat René , Asselin Christian , Jacquet A. , Pinard C.
Published: September 2016

In the framework of a research programme on the “ terroirs ” in viticulture, a red of experimental plots was established in the Loire Valley area in 1978 with the Cabernet Franc variety. In 1988, eleven of those plots were given an intensive follow-up, with special emphasis on the phenological stages, the growth and development of the vegetative apparatus and the composition of the grapes at harvest time. After a few years, we can consider that 1988 was an average year for the last fifteen vintages, both on the climatic side and on the wine quality side. Therefore it seems to be justified to use the data of that particular year to study the “ terroir ” effect on the composition of the grapes. The results show important differences between “ terroirs ” in terms of precocity of the phenological stages, stems growth, setting of the leaf area, vigour and productivity of the plants. These differences are found also during the maturity process and at harvest time ; sugars, organic acids, anthocyanins and polyphenols are concerned. An index for measuring the precocity of the grapevine cycle on each “ terroir ” is used to compare the “ terroirs ” and to establish relationships with the composition of the grapes at harvest time. Through the analysis of the data, it is possible to distinguish two groups of factors which determine the behaviour of grapevine in a given “ terroir ”. The first one is related to the precocity of the cycle of the plant ; it influences the quality of the grapes at harvest time. The second is related to the vigour ; it is linked to the productivity of the plants.and the acidity of the must. The level of development of the primary leaf area at flowering time seems to play an important role in relation with the composition of the grapes in sugars, organic acids and anthocyanins ; the earlier the flowering, the better the relationship.