bluuebunny/crossref_metadata_2025 huggingface dataset:
Grapevine fruiting cuttings: validation of an experimental system to study grapevine physiology. II. Study of grape development
Authors: Geny Laurence , Ollat Nathalie , Soyer Jean-Pierre
Published: September 2016

The study was carried out in order to compare the development of berries growing on fruiting cuttings and on vines from the field, and to evaIuate this experimentaI system for grapevine physiology studies. The results show that the main developmental characteristics of the berries are close to those of berries from the vineyard. Fruit set is good and berry growth follows a double sigmoid curve. Final size is smaller than usual, even if seed number is higher for fruiting cuttings. The evolution of organics acids, sugar and mineral content is classical. At maturity, the berries from fruiting cuttings reach the same sugar content, but are less acidic, because the components of acid equilibrium are slightly modified. At flowering polyamine content is higher in the cluster of fruiting cutting but the variations aIong cluster development is the same than in the vineyard. Finally the application of exogenous putrescin on fruiting cuttings at flowering time improves fruit set, as in the field. Our data allow to conclude that fruiting cuttings behave mostly as bigger vines and could be a usefull tool for grapevine physiology studies.
Evaluation of thermal regime of Vitis vinifera L. var. Melon during winter time in Québec
Authors: Jolivet Yvon , Dubois Jean-Marie , Granberg Hardy
Published: September 2016

The production of wine is a recent endeavour in Québec. In 1996, 95 p. cent of the commercial vineyards were found in the Eastern Townships and Montérégie regions, where climate puts severe constraints on viticulture. Very low winter time temperatures can occur and it is important to match vine hardiness to climate reality. This can be accomplished by plant selection and/or by application of variety of phytoprotective measures.

Field measurements of the thermal regime of different parts of vines (Vitis vinifera L. var. Melon) are reported here. Intratissular temperatures were recorded semi-continuously using fine (A WG n° 40) thermocouples and datalogger system. Measurements were recorded throughout the winters 1993-1994 in a vineyard near Sherbrooke, Québec. The measurements show that snow is very important factor ameliorating root-zone temperatures. Snow is also very important to keeping the aerial parts of the plant at temperatures well above their winter hardiness. Temperatures of 0°C to 4°C were recordeding snow cover parts of the plants even at ambient air temperatures near -30°C. During cold spells, following periods of melt with complete removal of the snow cover, cooling was notes down to a depth of 60 cm in the soil and the aerial parts of the plants closely followed the air temperatures. By contrast, if the cold front marking the end of the melting event was accompanied by snowfall, such extreme cooling did not occur. Even just a few centimeters of snow had very important thermal effects.

Our results suggest that noble grapes, which give a more interesting wine, but which are less hardy than their hybrid counterparts, can survive in Québec, provided they remain snow covered. A snow cover of only about 10 cm would suffice to protect the vines. Active management of snow cover conditions by means of snow fences, or even by production of artificial snow, may be useful venues to investigate.
Evaluation of the colour stability of enocyanines
Authors: Da Porto Carla , Zironi Roberto , Celotti Emilio , Bertolo Agnese
Published: September 2016

Probably the oldest naturaI food colorant was « enocyanin ». It is produced from grape skins as a byproduct of the wine industry in a number of countries, particularly Italy. The recovery of pigments from grape by-products has received considerable attention. Since wine grape skins are waste disposaI problem, obviously the source material is available at very low cost. The pigments in the Vitis vinifera group are 3-monoglucosides of cyanidin, peonidin, mal vidin, petunidin, plus the same compounds acylated with acetic, coumaric or caffeic acid. The hybrids may aIso contain the 3-5-diglucosides of the same aglycones and acylated compounds. Colorants from grapes may be expected to contain a number of other tlavonoids, tannin, organic acids, etc. The anthocyanins show greatest stability under acidic conditions, but are generally unstable and degrade easily according to various reaction mechanisms. The degradation is intluenced by oxygen, ascorbic acid, light, pH and temperature. Processing conditions used for the extraction and purification of pigments from wine grape skins can intluence color stability. The present work was undertaken to study how pH (pH 2, 3,4,5), time (15 days, 30 days, 60 days, 90 days) and temperature (4 oC, 24 oC, 36°C) intluence the color stability of enocyanins concentrated by ultrafiltration, inverse osmosis and under vacuum. The color of the different samples has been measured both by spectrophotometry and by Hunter L *, a*, b* values. The spectrophotometric (A420 ; A520 ; T ; 1 ) and colorimetrie (L *, a*, b*) data resulted correlated significantly. Therefore colorimetrie parameters which can be obtained by using a simple, rapid and easy method were used in order to study the color changes of the different enocyanins in the storage conditions. The obtained results have shown that the concentration techniques by ultrafiltration and inverse osmosis produced enocyanins characterized by a distinct red color, which was intense, but unstable in relation to pH variation. On the contrary, the enocyanins concentrated under vacuum resulted characterized by a poor red color, which was stable in relation to pH changes. In our experimental conditions, the results obtained showed that the degradation of the red col or, in relation to time and temperature, proved to be independent of the concentration technique used. A ready visuaIization of the chromatic evolution of the different enocyanins, with reference to the stability parameters studied, was obtained using the color diagrams.
Spatial terroir characterization and grape composition in the Southern Côtes-du-Rhône vineyard (Nyons-Valreas Basin)
Authors: Vaudour Emmanuelle , Girard Michel-Claude , Bremond L.-M. , Lurton L.
Published: September 2016

In order for the characterization of terroir in vineyard situations to benefit both viticultural and wine making practices, it is necessary to consider the spatial aspect of the vineyard environment. An exploratory approach at characterising terroir in the Nyons-Valreas Basin (figure 1) considers both the spatial analysis and frequency analysis of the harvest. Data gathered from stereoscopic aerial photographic examination, satellite image processing, land surveys, and the Digital Elevation Model are combined and structured within a Geographic Information System along with the existing soil and geological data (figure 2). The result is a comprehensive soils model applicable to a relatively large area (11,340 ha). The Nyons-Valreas Basin is a neogene and quaternary sedimentary basin, and the soils found there are described by 21 soil landscape units which integrate 15 variables (table I). The area examined is considered to be representative of the surrounding regional diversity. The variables used in characterising terroir include soil types, geomorphology, lithology, stratigraphy, vegetation, land form, and land use. The various viticultural terroirs are regarded as parts of agricultural land consistent with both soil landscapes and harvest/wine responses. Multivariate clustering of the soil landscape units indicates that there exists 7 distinct viticultural terroirs, essentially on the basis of geomorphology and soils (figures 3 and 4, table II). Four distinct terroirs were compared (figures 5 and 6) using data gathered from 14 sites over the course of 15 vintages (1982-1996). Grenache is the grape variety planted at each site, and the variables measured at harvest (pH, sugar content, titratable acidity, the weight of 200 berries, and the sugar/acidity ratio) appear to significantly discriminate the sites examined according to the terroir modeling performed (tables III, IV and V).
In vitro neoformation of grape chimeras (Vitis vinifera L.)
Authors: Verdisson Sandrine , Baillieul Fabienne , Audran Jean-Claude
Published: September 2016

Difference in grape sensitivity to Botrytis cinerea attacks between cultivars was explained by differences in the epidermic tissue of the fruit. Therefore, this work was conducted to create a grape periclinal chimera, whose fruits would combine the skin of a Botrytis tolerant cultivar with a pulp of an another cultivar admitted its good organoleptic quality and productivity. In a first time, graftings of two cultivars (Chardonnay and Pinot noir) were conducted in vitro on 5 different media supplemented with various plant growth regulators. Adventitious shoots were only observed on medium containing BAP and GA3 from a mixed callus structure after four weeks of darkness followed by a light/dark regime. In a second time, RAPD analysis, conducted on these plants, showed their chimerical characteristics.
Influence of the liquid or gazeous nature of the grape berries environment on rheological properties and on colour and nitrogen extractabilities during conditions simulating the Beaujolais wine-making process
Authors: Abbal Philippe , Sarris J. , Pradal Martine , Berger Jean-Luc , Robin Jean-Pierre
Published: September 2016

This study concerns the evolutions of some physicochemical characteristics of berries during conditions simulating the beaujolais wine-making process. In this process, a large number of intact berries is kept in a CO2 atmosphere which is produced by ethanolic fermentation of the must in the bottom of the tank. To simulate this, two equivalent samples of ripe Gamay or Carignane berries were placed in the same jar and subjected to carbonic anaerobiosis. One sample was maintained in the gaseous atmosphere and the other submerged in the liquid which was either an aqueous solution of 6 p. cent ethanol (v/v), the same solution with 1 M sorbitol, or grape must obtained from crushed berries. The aim of these experiments was to study, in both submerged and non-submerged samples, the effects of ethanol on rheological properties of berries and on potential extractabilities of colour and soluble nitrogen from skin and berry flesh. Whatever the model, ethanol had a deleterious effect on berries, especially on those which were immersed. For those, the development of anaerobic metabolism was drastically reduced, but nitrogeneous and colouring compounds extractabilities were significantly increased. The anthocyanins and their copigments seem to be preferentially extracted when berries were immersed. The rheological properties were related to the osmotical strength of the submerging liquid. It was assumed that hydratation or dehydratation phenomenons of cell-wall polysaccharides could explained the differences observed in the rheological behaviour of berries and in particular the modifications of their pellicular elasticity.
Observations on the oxygen consumption during maturation of wines on lees
Authors: Fornairon-Bonnefond Caroline , Mazauric Jean-Paul , Salmon Jean-Michel , Moutounet Michel
Published: September 2016

Traditional enological practices (« Bâtonnage » or « microoxygénation » techniques) during wine aging on yeast lees include limited repetitive additions of small amounts of oxygen to the wines. Such empirical practices are generally associated with a limited homogenisation of wine and lees. In this study, the potential relationship between oxygen consumption and the presence of wine lees during wine aging was investigated. Strong oxygen uptake rates by yeast lees were observed during wine aging at 14°C on total yeast lees obtained after fermentation of either synthetic medium or red and white grape musts. These specific oxygen utilization rates by yeast lees is always comprised between 3 and 11 μg O2 h-1 10-9 cells from the second to the sixth month of aging. The initial levels of specific oxygen utilization rates and the time-decay of these rates along wine aging were very dependent on yeast strains. However such oxygen utilization rates by yeast lees could be responsible for the total dissolved oxygen depletion from wines in less than 20 hours at 14°C during aging on total lees. Such results were of particular importance to evaluate the exact timing of oxygen additions during wine aging on lees. Further experiments had to be done to determine the biological or chemical nature of such oxygen consumption by lees. Such oxygen consumption by yeast lees may lead to final reaction products which may exert strong organoleptic effects on the final quality of wines.
Selective breeding of Saccharomyces cerevisiae to increase glycerol levels in wine
Authors: Prior Bernard A. , Baccari Clelia , Mortimer Robert K.
Published: September 2016

Glycerol in wines is at levels of 1 to 10 g/l and improves their body. To breed wine yeast for increased glycerol production, we crossed yeast isolated from natural fermentations with a commercial strain. The average glycerol concentration of 187 wine yeast strains was 4.2 g/l. Strain Ba25 had the highest glycerol production and a spore clone of Ba25 was crossed with one of Premier Cuvée, the best commercial strain, by spore-spore pairing and this was repeated three times. Several of the spore clones produced >15 g/l of glycerol. Glycerol and ethanol levels were inversely related.
Influence of cluster thinning on the amino acids concentration of musts and wines of the variety Vilana. Effect on wine volatile compounds
Authors: Bena-Tzourou Irène , Lanaridis Panos , Metafa Maria
Published: September 2016

In this work, the influence of cluster thinning on the amino acids concentration of musts and wines was studied. Three vineyards were selected from Peza district of Crete where the white vine variety Vilana is cultivated. One part of each vineyard, containing 100 vines was divided in two sections. The first was used as reference while in the second section, cluster thinning to 50%, just before veraison, was applied. The experimentation was repeated for two continuous years. In 1996, the reference sections yielded 35.5 – 46.7 t/h while the other sections, where cluster thinning took place, yielded 16.5 – 23.0 t/h. The next year, the yields were 43.2 – 48.4 t/h and 12.6 – 14.0 t/h respectively. In all musts and wines, 18 amino acids were determined with the use of HPLC and proline was determined colorimetrically. The volatile components of the wines were also measured because, as it is known, the amino acids contribute to the formation of some higher alcohols, ethyl esters and acetates. From this work the following conclusions were made:

The musts and the wines from Vilana variety are poor in amino acids and their levels vary from one year to another. This variation is related to the climatic conditions of the period of maturation but the profile of these acids seems invariable.

The musts of Vilana variety deriving from vineyards with cluster thinning, which lead to low yield, contain higher levels of amino acids. This is important, given that a must rich in amino acids, positively influences not only the fermentation process evolution but also the enrichment of the wines in volatile components. Particularly for the Vilana variety, which is poor in amino acids and without any typical aroma, the high yields have a negative effect on their wine quality.
Determination of synthetic colorants and natural carmine in wines
Authors: Virtanen S. , Ali-Mattila Eero , Lehtonen Pekka
Published: September 2016

Methods were developed for the determination of synthetic colorants and natural carmine (E120) in wines. The synthetic colorants studied were tartrazine (E102), quinoline yellow (E104), sunset yellow (E110), azo ruby (E122), amaranth (E123), ponceau 4R (E124), and erythrosine (E127). The colorants were extracted using solid-phase extraction (SPE) with NH2 cartridges. The extracted colorants were then analysed by high-performance liquid chromatography (HPLC). The compounds were identified by comparing the spectrum of extract with spectra in a UV-vis spectral library of known food colorants. The detection limits in red wine ranged from 0.1 mg/l to 0.2 mg/l. Diode array detection and library search makes the method very effective in identifying forbidden colorants in wines. SPE is sufficiently effective in separating and concentrating colorants from wine. The effect of added colorants, e.g. azo ruby (E122), amaranth (E123) and tartrazine (E102) on the UV-vis spectra of red and white wines were studied. The added colorants could be identified in this way but not as accurately as by the HPLC method.
Influence of the context on the perception of wine cognitive and methodological implications
Authors: Brochet Frédéric , Morrot Gil
Published: September 2016

The influence of the context on the perception of food is studied by having a group of 57 french oenology students tasting the same wine in two different packages (common table wine VDT and grand cru classé GCC). This context modification does not affect the stimulus itself but only the cognitive part of the perception. Results show that the packaging induces different judgments for the same wine. All the tasters give different marks for both wines and the GCC wine has significant (52/57) best records. Lexical analysis of wine tasting comments in both contexts reveals totally opposite describing behaviors of the tasters, most of the subjects looking for faults in the wine presented as VDT and seekink qualities in the GCC labeled wine. Subjects tend to adjust their sensory perceptions to the quality suggested by the label. From a sensory analysis point of view, our results emphasize the role of context in food perception. The perceived flavour of the wine is different when it is tasted in a different context. From a cognitive point of view, these data suggest that the conscious perceptive representation of the food contains information from different origins and that a subject is not able to selectively extract chemiosensory information from this global representation.
A review. Biochemical and molecular mechanisms in Saccharomyces cerevisiae that are involved in the formation of some volatile compounds in wines
Authors: Delfini Claudio , Cocito Chiara , Bonino M.
Published: September 2016

There are evidences that a grape must of a non aromatic vine, not having perfume and revealing by gaschromatographie only some classes of compounds common to the musts of all the vine varieties, can originate a pool of characterizing fragrant substances after contact with the yeast during fermentation. Therefore, despite the scarce scientific knowledge available on biochemical mechanisms involved in Saccharomyces cerevisiae in the formation of a wine aromatic pattern, it can be likely hypothesized that the yeast could be the biological motor of this aromatic transformation. The yeast can act on the compounds of the must with many periplasmic enzymes (estérases, glycosidases, lyases, lipases, proteases, peptidases, pectolytiques) and several are the scientific contributions underlining the existence of an interaction between the yeast and the vine variety in the formation of wine aromatic characteristics. Besides the individual contribution of substances sensorially active, the yeast would contribute to the transformation of unknown varietal aromatic precursors that are in the grape skins and/or musts. The biochemical, genetic and physiological aspects of this transformation still have to be understood. At the end, we have to answer some important questions such as the mutual role that grape and/or yeast enzymes have during and soon after crushing in the liberation of the varietal precursors and in the conversion of these in fragrant compounds.
Persistence of blood paste proteins in a dry white wine after clarification
Authors: Douet J.-P. , Médina Bernard , Castroviejo Michel
Published: September 2016

Until the end of 1997, plasmatic proteins and blood cells could be used to clarify wines. The aim of our work was to study the persistence of these animal proteins in a dry white wine during clarification. The effects of some clarification parameters were also estimated.

We used two protocols to discriminate between blood paste proteins and native proteins of unclarified wine (e.g. from grapes, yeasts, bacteria). The first protocol was a radiolabel of blood paste proteins with chloroglycouril and Na125I. The 125I-labelled animal proteins were revealed with autoradiography of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and quantified with a gamma scintillator. The second protocol was purification with affinity chromatography. The antibodies of this affinity chromatography were specific of whole beef serum. After this purification, harvested proteins were loaded onto two-dimensional gel electrophoresis (2D). After migration, proteins were silver-stained.

With the radiolabel protocol, we show that the concentration of animal proteins found in dry white wine after clarification and filtration increased with the concentration of blood paste proteins used during clarification. This relation is almost linear. The duration of the blend blood paste / wine incubation step is also a significant parameter. After incubation for one minute, about 40 p. cent of animal proteins were found in clarified and filtered wine. After four days of incubation, a maximum of 88 p. cent blood paste proteins were found in both clarified and filtered wine. The use of bentonite decreased 4-to 6-fold the concentration of blood paste proteins. The filtration step also strongly decreased the concentration of these proteins : quantitation with a phosphoimager showed that wine clarified (with 250 μg of blood paste proteins in 4 heures of incubation time, without bentonite) and filtered retained 6 p. cent, i.e. 12 mg of blood paste proteins. The membrane porosity (0,2 or 0,45 μ) for the filtration had no effect.

Affinity chromatography and 2D procedures also showed that proteins of animal origin could subsist in wine after clarification, while others in the original composition of wine disappeared.
Influence of water status on vine vegetative growth, berry ripening and wine characteristics in Mediterranean Zone (example of Nemea, Greece, variety Saint-George, 1997)
Authors: Koundouras Stefanos , Van Leeuwen Cornelis , Seguin Gérard , Glories Yves
Published: September 2016

The influence of grapevine water status on vine physiological mecanisms and vigour, as well as on berry ripening and wine characteristics, was studied during the summer of 1997 in the Nemea vine growing area (Peloponnesus, Greece). This involved three non irrigated vineyards planted with the local variety Saint-George (Agiorgitiko). These vineyards differed by their soil texture and by the presence of a water table within reach of the roots. The soil of the plot "A", located at 350 m in altitude, contained a high amount of gravel and stones between 0 and 50 cm in depth. The subsoil contained nearly 50 p. cent of clay. The plot "L" was located on a plain at 300 m in altitude. Its soil was very loamy. The plot "N" was located on a plain at 260 m in altitude. Its soil contained a high amount of clay and loam but its main caracteristic was the presence of a permanent water table within reach of the roots. Vine water status was evaluated throughout the season by measurements of leaf water potential Ψ. Additional measurements of soil water content were executed by means of a TDR moisture probe (Time Domaine Reflectometry). Water uptake of the vines showed great differences on the three plots. On the plot A, water uptake of the vines diminished brutally from June (pre-dawn Ψ= -0,2 MPa) through September (pre-dawn Ψ= -1,0 MPa); measurements of stomatal conductance in early September showed that stomata remained practically closed throughout the day. On the plot N, water was easily available to the vines throughout the summer. Pre-dawn leaf water potential remained between 0 and -0,2 MPa from June till September. Stomatal conductance, measured in early September, was high. On L, vine water status was intermediate: pre-dawn leaf water potential declined throughout the season, but not as dramatically as on A. Stomatal conductance, measured in early September, was intermediate between N and A. Water availability had a clear effect on vegetative growth. Growth slackening occured early in the season on A and late on N. On plot A, berries were smaller and showed high sugar and anthocyanin concentration and low malic acid content. Wine from A, obtained by mini-vinification (3,5 hl), was rich in alcohol, anthocyanins and tanins. On N, berries had a low sugar and anthocyanin content. Wine from grapes grown on N was poor in alcohol and polyphenolics. Berry and wine composition was intermediate on L.
Influence of some activators of alcoholic fermentation on amino acids composition and fermentability of Vitis vinifera cv. Muscadelle musts from permanent grass covered plots
Authors: Larchevêque Corine , Casanova A. , Dupuch Vincent
Published: September 2016

The duration of alcoholic fermentation was very different with the no-tillage trial must and the other grass-cover musts. The duration was found to be quite closely correlated to the content of nitrogen components in the must and more particularly to amino acids. Several supplementations were tested during the two experimental years. It should be noted that European legislation doesn’t allow the use of some of them. The durations of alcoholic fermentation of musts with these added activators were shortened. Again, fermentation duration was quite closely correlated to the content of nitrogen components in the must and more particularly to amino acids. It is noteworthy that numerous kinds of amino acids were present. Some of them were very important either by virtue of their nature or their concentration levels. A statistical analysis showed some composition similarities between some musts, but there were composition differences which would explain their fermentation kinetics.
Yeast strains role on the sulphur dioxyde combinations of wines obtained from noble rot and raisining grapes
Authors: Masneuf-Pomarède Isabelle , Dubourdieu Denis
Published: September 2016

The influence of four industrial and indigenous yeast strains on the sulphur dioxide combinations of wines obtained from noble rot and raisining grapes is studied in different growth of the Sauternes area and one growth in the Jurançon area. The analysis of ketonic compounds (pyruvic acid and 2-oxo-glutaric acid), acetaldehyde and PC50 on the wines clearly showed significant statistical difference between the yeast strains for the sulphur dioxide combination. By adding the same dosage of sulphiting, the free SO2 levels are variable depending on the yeast strain used. One strain (Zymaflore ST), isolated from a spontaneous fermentation of a botrytised must, giving wines with low PC50 values, is well adapted for the noble rot must vinification. The choice of the yeast strain is a parameter of importance to limit the sulphur dioxide amount in the wines.
Free amino acids of leaves and berries of Cabernet Sauvignon grapevines
Authors: Miele Alberto , Carbonneau Alain , Bouard Jacques
Published: September 2016

The composition of free amino acids was studied from leaves, pericarps, skins, musts and seeds of Vitis vinifera L. cv. Cabernet Sauvignon. Vineyards were in the Bordeaux region and the grapevines were conducted in espalier and lyre systems. Grapes were collected at maturity and lyophilized after sampling. Extraction of free amino acids was done with a hydroalcoholic solution and their analysis was performed with an autoanalyzer. A standard of 34 amino acids was utilized for the qualitative analysis. The results showed that, for both espalier and lyre training systems, respectively, the free amino acids were predominant in the pericarps (12.85 and 11.21 mg/g dw) - 16.88 and 15.12 mg/g dw in skins and 3.29 and 2.88 g/l in musts -, followed by the seeds (2.37 and 2.32 mg/g dw) and leaves (1.87 and 1.98 mg/g dw). The most abundant free amino acids in leaves were glutamic acid (23.8 and 28.8 p. cent), aspartic acid (8.8 and 11.1 p. cent), and glutamine (10.1 and 9.4 p. cent). Proline (41.8 and 41.5 p. cent) and arginine (22.8 and 22.4 p. cent) predominated in the pericarps. In seeds, the main amino acids were proline (14.5 and 15.8 p. cent), arginine (11.0 and 11.8 p. cent), histidine (11.2 and 8.7 p. cent), and glutamic acid (11.3 and 8.2 p. cent). Grapevine training system showed some differences in the total amount and in the percentages of each free amino acid, but the pattern of these compounds for each tissue was similar for both training systems.
A contribution to the characterisation by electrophoresis of grape plant varieties cultivated in Galicia (NW Spain)
Authors: Saa-Otero María del Pilar , Cid Álvarez Nuria , Boursiquot Jean-Michel
Published: September 2016

Electrophoresis was employed as the method of study for the characterisation of Vitis vinifera varieties cultivated in Galicia (Spain). Mature dormant shoots were used for the study. The enzymatic system glucose- phosphate isomerase (GPI) was analysed using the method of PARFITT and ARULSEKAR (1989). Seventeen varieties (Albariño, Dona Blanca, Godello, Loureira, Treixadura, Torrontés, Albillo, Palomino, Verdejo Blanco, Macabeo, Jerez Fina, Asal Galego, Moscatel Galego, Galego Dourado, Galego de Montemor, Brancellao, and Caiño Bravo) were studied. Eight groups of phenotypes were obtained. Each one of which had clearly differentiated characteristics from more than one varity, except in the case of Garnacha.
Effects of forchlorfenuron (CPPU) and girdling on table grape cultivars "Perlette" and "Italia"
Authors: Ezzahouani Aziz
Published: September 2016

A study was conducted to determine the effects of post-bloom applications of forchlorfenuron (CPPU) at 5 and 10 ppm, and the practice of cane girdling on fruit quality of two table grape cultivars (cvs.) « Perlette » (seedless) and « Italia » (seeded). For « Perlette » cv, CPPU treatments increased significantly berry weight and crop per vine, relatively to the control. However, soluble solids decreased while the acidity increased, reflecting a late maturation of berries from the treated vines. The delay of fruit maturity was also observed in « Italia » grapes, measured by a significant decrease in fruit soluble solids content. Girdling had a slight and non significant effect on fruit quality for both cvs.
Artificial intelligence in wine-making
Authors: Grenier Pierre , Álvarez Inmaculada , Roger Jean-Marie , Steinmetz Vincent , Barre Pierre , Sablayrolles Jean-Marie
Published: September 2016

In this paper, some terms of Artificial Intelligence are defined. Some present and potential applications of knowledge based systems are presented in the field of wine-making. Areas of concern were: multi sensor fusion, prediction by model cooperation, and diagnosis. Artificial intelligence techniques can indeed be applied for aiding the wine-maker in his choices. They facilitate the combination between experience and recent progress in technology. When associated with statistical processing, they allow knowledge sources to be used more effectively. Beyond wine-making, the prospects of artificial intelligence are promising for research and food industry, especially for improving the robustness of measurement systems (multi-sensors, sensors interpreted or validated by models), and for process diagnosis (risk prediction, action proposal).
Determination of benzothiazole in grapes and wines
Authors: Karagiannis S. , Lanaridis Panos , Salaha Marie-Jeanne
Published: September 2016

Benzothiazole was measured in grapes from Muscat Lefko vines from the Isle of Samos and in Muscat d'Alexandrie vines from the Isle of Lemnos. Differences were noted in regard to altitude, soil composition and exposure, and in the corresponding wines. This compound was also determined in grapes of ten other white grapevines cultivated in Greece, and in their corresponding wines. The results show the presence of benzothiazole in all of the grapes examined, and that it might have been formed during the maturation of the grape. The levels of benzothiazole varied from 0.8 to 6.1 mug/l; this was always below the threshold of perception.
Micromorphometric changes in trunk diameter in relation to mild water stress in field grown vines
Authors: Van Leeuwen Cornelis , Lerich Olivier , Renard Romain , Trégoat Olivier , Alla Pierre-Luc
Published: September 2016

Continuous measurement of micro variations in the diameter of woody organs provides an early detection of mild water deficits in field grown vines. Trunk diameter variations gives more reliable data than cane diameter variations. Water deficit induces trunk shrinkage and increases the Daily Contraction Amplitude / Potential Evapo Transpiration ratio ( DCA / PET). This does not occur on irrigated control vines. Moreover, micromorphometry appears to be an accurate technique for detecting short-term water deficits, because the measurements are continuous. Major constraints in the use of micromorphometry on field grown vines include the positioning of sensor needles on the trunk and the need to maintain fragile equipment permanently in the vineyard. Additionally, this method does not quantify water deficits.
Soil reflectance and colouring of grape. Vine red light excitation could be decisive for grape berry quality
Authors: Robin Jean-Pierre , Sauvage François-Xavier , Pradal Martine , Chovelon Marc
Published: September 2016

Various conditions of vine « solarisation » with sun light reflecting clothes partially colored in blue, green or red, were performed in field conditions during 1998 and 1999 years.The experiments were conducted both on table grapes (Muscat de Hambourg , Italia and Danuta) and on wine grapes varieties (Carignane, Mourvèdre, Shiraz, Muscat à petits grains). The « solarisation » clothes were set up at the cluster closure stage and removed at the harvest time. Effect of various experimental conditions on changes in situ berry colour was examined. The chromatic parameters using the Lab and LCH conventional systems were weekly measured on representative berry samples, and levels of significance of the obtained differences were determined by a variance analysis. Differences in the colouring dynamics and in the values of the chromatic parameters at harvest were statistically significant, in particular in function of the importance of the reflecting area set up per vinestock and also in function of the color of the reflecting cloth used. The results were compared to those obtained from various other analyses : reflectance spectra and composition of berries at harvest, tastings of the table grapes. As a main result, the red colour with a maximum of reflectance at 680 nm appeared as the more effective in improving quality of the berries. These results demonstrate the importance of the reflectance properties of the neighbours of the vine, in particular those of the soil of the parcel, on the composition and the quality of the grape. Moreover, they underline that these properties should be taken in account to explain some misunderstood terroir effects. Finally, they strongly suggest that the excitation of vine photoreceptor systems, specially with the clear red light, could be decisive in the signaling and regulatory mechanisms leading to an optimal ripeness of the grape.
Quantitative analysis of the killer activity of some oenological yeasts. Effect of some additives
Authors: Alfenore Sandrine , Délia Marie-Line , Strehaiano Pierre
Published: September 2016

The Killer factor was discovered in 1963. Since this time it has been widely studied and nowadays a lot is known about genetics of the factor, the biochemistry of the toxin and also about the way of action of the toxin on sensitive yeasts. The yeast strains are classified in three groups : killer strains, sensitive strains and neutral strains. The killer strain is able to kill sensitive strains while neutral strains are unable to kill any strain and remain unaffected by the toxin. Certainly this classification depends on the couple of strains (killer and sensitive) taken as references. It has been clearly established that the toxin acts on the sensitive cells by inducing important losses of ATP : due to holes created by the toxin in the cell membrane, ATP leaves the cell.

In the field of Enology, it’s generally accepted that a killer yeast has more probabilities to have a good implantation in a non sterile medium (as the must is) than a neutral or a sensitive strain. Nevertheless, it is difficult to have a precise idea of the sensitivity of a strain as well as of its toxicity, as most of the methods are only able to give a qualitative information.

In this paper, a new method of evaluation of the killer effect is presented. Also some results dealing with its application to the classification of some enological yeast strains are given and discussed.

This method is based on the measurement of the ATP released by the sensitive strain under the action of the killer toxin. The criterion that we define is the initial rate of ATP release, that means the quantity of ATP lost in the two first hours by the sensitive cells in contact with the toxin. In a first step, it is shown that this method is reliable and also that it is in a good agreement with the method using the flow cytometry. ATP leak could be correlated with the amount of affected cells (dead and damaged cells). So, using this method, it becomes possible to classify easily yeast strains with respect to their sensitivity or toxicity. Several killer yeast strains were tested against a sensitive strain and different sensitive strains were submitted to the action of a killer toxin produced by a killer strain. It was shown that the losses of ATP were quite different according to the sensitivity of the strain. The initial rate of ATP release was found to be in a range of 0.00 to 0.12 micromole/L/h. The second part of the work deals with the study of the possible effect of some products used for winemaking on the efficiency of the killer effect. The products we have studied were bentonite, tannic acid and enological tannins. It is shown that these products may interact with the killer effect. So, bentonite, for example is able to inhibit completely the efficiency of the killer toxin, as soon as its concentration is about 10 grams/hL.
New contribution to the survey of the theory of the acrotony on the branch of one year grapevine: II - Influence of growth regulators on bud burst carried by one eye cuttings in post-dormancy stage
Authors: Ezzili Béchir , Bejaoui M.
Published: September 2016

Investigation of the Tunisian vineyard showed that on long canes of Muscatel of Italy, a certain percent of growing branches presents both the acrotony and basitony phenomena. The discussion of the investigation results allowed us to define a new hypothesis according to which these phenomena are controlled in part by a hormonal balance. In order to test this hypothesis, we are proceeded by studying the influence of growth regulators on bud bursting carried on one eye cuttings in one hand and on long canes to 10 units cultivated in greenhouse and in the laboratory on the other hand as well as on long wood in the vineyard. We report in this work the results relative to one eye cuttings. We applied an immersion of buds carried by one eye cuttings and in phase of post-dormancy, during 24 hours in different growth regulators at different concentrations (GA3 50 mg/l, 25 mg/l, 12.5 mg/l; ABA 25 mg/l, 12.5 mg/l, 6.25 mg/l; 6BAP 50 mg/l, 25 mg/l, 12.5 mg/l; Kinétin 50 mg/l, 25 mg/l, 12.5 mg/l; AIA, AIB, ANA 50 mg/l, 25 mg/l, 12.5 mg/l; 2-4D 10 mg/l, 5 mg/l, 2.5 mg/l). Results of these treatments show that there are generally some inhibitory effects for gibberellins and auxins. In the contrary, cytokinins possess the stimulate effects of bud bursting, applied during the end of the post dormancy phase.

The interesting conclusion concerning the interaction of two growth regulators resides especially in the interaction cytokinin-auxins. According to our results auxins possess some inhibitory effects on the bud bursting, on the contrary, cytokinins possess a stimulate effect. The Interaction cytokinin-auxin seems to attenuate the negative effect of auxins on the bud bursting. We will see subsequently that differed applications of these regulators can give a clear demonstration.
Preliminary evalution of artificial snow cover as a method for the protection of the vine during winter in Québec
Authors: Jolivet Yvon , Dubois Jean-Marie
Published: September 2016

The sensitivity of the vine to cold temperatures makes it a high risk crop in Québec. Winter colds during January and February can reach through the course of several days - 30° C and consequently the intense cold can damage the buds. However, during this same period, the snow cover normally present on the ground insures a certain protection to the aerial portions of the vine by insulating them from the intense cold air dominating the surface. Moreover, given the random character of the snowfall regime, vine growers must in addition ridge the vine stocks to protect them from the cold. This research work discusses artificial snow making as a method of protection for the vine and addresses one of the major problems faced by this type of culture under extreme climatic conditions.

Temperature measurements were recorded over four experimental plots during the cold season in a vineyard in Québec. A plot covered by artificial snow for protection against the winter cold was compared with three others, one with a natural snow cover, one with a leaf cover and covered by natural snow and one covered by natural snow with fine ice crusts following snowfalls. Results show that during the major colds of January and February, the vine shoots located at 30 cm from the ground and protected by artificial snow conserved much higher negative minimum temperatures, by as much as 23°C compared to the vine shoots located at the same height on the other plots. Results also reveal that a snow cover of 15 to 20 cm is sufficient to insulate entirely the vine shoots from the ambient air. Hence, the use of artificial snow cover is an efficient method of protection against the cold. However, when using artificial snow covering in the fall while the natural snow cover is still absent, non crystallized water penetrates the ground down to the root zone through percolation and reduces the temperature by approximately 3°C down to a depth of 30 cm. In the same manner, in relation to traditional methods of protection, during spring the early thawing of the snow cover at the center of the ridges leaves the vine shoots without protection and exposes them to late frosts.

Other results relating to the use of artificial snow for covering stocks with regards to bud mortality rate and fruit yield in the fall should permit the evaluation of the real impact of this method on stock productivity and the quality of production.
Effects of wine on cellular and endocellular membranes in vitro
Authors: Wattiaux Robert , Jaworski Kathy , Wattiaux-De Coninck Simone
Published: September 2016

Several observations suggest that wine consumption could have beneficial effects on health by preventing cardiovascular diseases. Apparently, ethanol is not the only component responsible for these effects, phenolic substances: tanins, flavonoids may have an important role. As these compounds are able to affect biological membranes, we investigated the effect of wine in vitro on two model membranes: the lysosomal membrane and the red cell membrane. The integrity of rat liver lysosomal membrane was assessed by measuring the latency of Nacetylglucosaminidase, a lysosomal enzyme, when the organelles are subjected to free radicals of oxygen in the presence of different concentrations of wine. The state of red cell membrane was followed by determining hemolysis caused by phospholipase C. Our results show that low concentrations of red wine prevent the deterioration of the membrane of lysosomes induced by oxygen free radicals generated by the xanthine-xanthine oxidase system and oppose hemolysis induced by treating red cells with Clostridium welchii phospholipase C. White wine is considerably less efficient. As similar effects can be obtained with some phenolic compounds, it is probable that the membrane protective effects of red wine that we describe, originate from its content in these substances.
Evaluation of a commercial grape yield monitor for use mid-season and at-harvest
Authors: Taylor James A. , Sanchez Luis , Sams Brent , Haggerty Luke , Jakubowski Rhiann , Djafour Sarah , Bates Terence R.
Published: September 2016

Aims: Yield monitors are becoming more common in North America. This research evaluates the precision and accuracy of a retro-fitted, commercially available grape yield monitor mid-season, for crop estimation and crop thinning applications, and at harvest for yield mapping.

Methods and Results: Several grape yield monitors were mounted on the discharge conveyor belt of grape harvesters in both commercial and research vineyards in North America. Sensor response was compared to manual measurements at multiple masses, ranging from 20 kg to 28 Mg over the course of three seasons. Measurements were taken during crop thinning and estimation (mid-season) and at harvest. Results showed that the grape yield monitor performance was sufficient to generate good spatial maps of the relative variation in harvest yield and mid-season thinned yield. However, at harvest the sensor showed a shift in response between days of up to ±15%, such that the generation of absolute yield maps required a daily calibration against a known mass. Within a day (single harvest operation) the sensor response did not appear to drift. Mid-season applications required a different calibration to harvest applications.

Conclusion: The yield sensor worked well for both mid-season and at harvest operations in North American vineyards but required a daily calibration to avoid drift issues. The mid-season yield calibrations were different between seasons; however, the harvest calibration factor was stable between seasons.
Significance and Impact of study: The study showed that a commercial yield monitor with correct calibration was effective at even low fruit flow. This opens the possibility of using a harvest sensor mid-season to mechanically estimate fruit load from small point samples and to map the amount of fruit removed  during fruit thinning operations. This will improve the quality of information available to viticulturist to understand fruit and crop load. The commercial yield monitor is suitable for use in North American vineyards.