Benoit Bach
email: benoit.bach@eichangins.ch

Mélissa BLIND a , Aurélie Peyches-Bach

Eric Martine

Didier Louvier

Julien Ducruet

Oenococcus Oeni

Adheree Sur

L E Bois

D E Chene

Alexandre Bastard
email: alexandre.bastard@u-bourgogne.fr

Christian Coelho
email: christian.coelho@u-bourgogne.fr

Régis Gougeon

Stéphanie Weidmann

Jean Guzzo

Roullier Gall

Michael Gonsior

Philippe Schmitt- Kopplin

Régis Gougeon

Nwabisa Mehlomakulu

Mathabatha E Setati

Benoit Divol
email: divol@sun.ac.za

Joana Fernandes

Rodrigo Neto

Filipe Centeno

Fátima Teixeira

Ana Catarina Gomes

Attila Kiss
email: attkiss@ektf.hu

Gábor Csiffáry

Csaba Csutorás

Tamás Várhelyi

Zoltán Murányi

Roberto Larcher
email: roberto.larcher@fmach.it

Loris Tonidandel

Giorgio Nicolini

Tomas Román Villegas

Mario Malacarne

Bruno Fedrizzi

Valérie Lempereur
email: valerie.lempereur@vignevin.com

Y Z Liu

P Schmitt-Kopplin

Forcisi S b,c , Harir M b,c Rd A Gougeon

DEVELOPMENT OF ANALYTICAL METHODS FOR DETERMINATION OF OXYGEN INGRESS IN BAG-IN-BOX®

Keywords: Bag-in-Box®, oxygen transfer, acid ascorbic, Chapon method, luminescence-based technique Oenococcus oeni, Exo-polymères, biofilm, chêne La fermentation malolactique Emission Excitation Matrices, PARAFAC components, white wine, ageing killer toxins, non-Saccharomyces yeast, Brettanomyces bruxellensis, yeast interactions Allergenic, clarification, enological yeast, fining agents, proteins, stabilisation, wine sulfite oxidase, enzyme isolation, biosensor skin maceration, thiol precursors, LC-MS oenological tannis, thiol precursors, LC-MS Yeast, Malolactic bacteria, Interaction, Wine, FTICR-MS, LC-MS, Metabolomics Contribution

Grape maceration and skin contact is one of the first steps in winemaking and it can condition wine aroma profile and flavour. Several studies have shown how the oxidative maceration occurring in machine harvested grape [1,2] can increase the level of thiol precursors and relevant free thiols. This latter even is particularly important due the extremely high impact these molecules on final wine aroma.

Believing that machine harvest alone could be the Holy Grail of thiol production could underestimate the complexity of the pathways available and the lack of knowledge about where these molecules are originating from (only few % of the known pathways are explaining the free thiols found in wine).

This communication wanted to explore to a closer detail on a larger scale the effect of maceration on the production of two known precursors (S-3-glutathionyl hexan1-ol and S-3-cysteinyl hexan-1-ol) [3]. 19 Mueller Thurgau and 32 Sauvignon blanc were considered and results seemed to be a bit more complex than what was envisaged in the literature.

Increases of the two precursors were observed only in some sample (not all of them as other found), highlighting how the simple oxidation mechanism might not explain completely the de novo formation of thiol precursors in all grape/wine samples.

ESTERS IN WINES: NEW INSIGHT THROUGH A SURVEY OF FRENCH WINES

The concentration of esters, their association and interactions with the sensory perception of wine has recently garnered the attention of wine scientists investigating [1][2][3][4]. Esters are no longer considered to impact the aroma of young but are important markers of fruity notes of wines of varying age. Considerable knowledge regarding the role of the concentration of esters in wines from a quantitative point of view was mostly been generated in the 1980s but was limited to few compounds, mainly on ethyl esters of fatty acids (EEFAs) and higher alcohol acetates (HAAs) [5][START_REF] Bertrand | Volatiles from grape must fermentation[END_REF][START_REF] Sumby | Microbial modulation of aromatic esters in wine: Current knowledge and future prospects[END_REF]. In this context, there was considerable interest to generate a database on the concentration of a variety of esters to improve the knowledge of wine composition. This work aimed to establish a database specific to esters in wines by quantification using HS/SPME-GC/MS [START_REF] Antalick | Development, validation and application of a specific method for the quantitative determination of wine esters by headspace-solid-phase microextraction-gas chromatography-mass spectrometry[END_REF] of 30 esters in 183 commercial French wines. Wines from 1 to 29 years old, from different types and styles (normal red, red from carbonic maceration, dry white, sweet white, rosé) and origins were analysed. Higher levels of EEFAs were found in wines made at low temperature (white and rosé) whereas HAAs synthesis was rather favoured in strict anaerobiosis (red by carbonic maceration (RCM), white). On the contrary, ethyl esters of branched acids (EEBAs) and cinnamates displayed higher concentration in wines made with grape skin contact (RCM, red). These results suggest that lipid and amino acids composition of the must as well as the redox balance of yeast metabolism may play a major role in the formation of esters in wines. Moreover, while EEBAs levels increased during ageing at similar rates in white and red wines, hydrolysis reactions were observed only for HAAs in white wines and for ethyl decanoate and dodecanoate in red and white wines. Furthermore, few trends were highlighted in the ester composition of wines originating from different area. Beyond the fundamental interest in oenology, this database offers potential new research paradigms in grape and wine biotechnology which could lead to relevant applications for the wine industry in the future.

One of the limiting properties of the polymeric material is the permeability of molecules with low molecular weight as O 2 and remains its major brake to general use by the private sector. So, it is generally accepted that accelerated oxidation is unfavourable for the wine evolution. After dissolution into wine, oxygen triggers series of reactions that are responsible of aroma modification, colour and mouth-feel properties. For wine, determining the properties of oxygen transfer through the films used in packaging remains a challenge [1]. Currently, there are no instruments or standard methodologies allowing industries to determine easily the evolution of wine in Bag-in-Box® (BIB). The reference method used at the moment to determine the permeability of a part of the BIB (bag or tap) is the Ox-Tran® from Mocon®.

The aim of this work was to develop an alternative method which can determine the entire permeation of the BIB. Studies were done by using several analytical methods such as wine model solution with acid ascorbic as oxidation index, measurement based on the reduced power (Chapon method) with a tannometer [2] and luminescence-based technique [3]. Therefore, tests were done by using gas/gas and gas/liquid exchanges. These methods allowed us to test different plastics bags and taps. All developed methods are simple, easy to use and allow BIB testing as a whole.

Oenococcus oeni qui permet une désacidification, une stabilisation microbiologique et le développement des qualités organoleptiques du vin. Puisqu'elle est présente dans l'environnement viti-vinicole, cette bactérie indigène peut déclencher une fermentation spontanée : ses capacités d'adhésion ont donc un impact sur la qualité du vin. Par ailleurs, l'interface entre le bois et le vin est le siège de transferts de composés du bois vers le vin et inversement de sorption de composés du vin par le bois [1,2], Or, le développement d'un biofilm à l'interface entre le bois et le vin peut éventuellement favoriser ou interférer les transferts de molécules aromatiques. La matrice du biofilm est constituée d'exo-polymères saccharidiques, nucléiques et peptidiques, ainsi que des enzymes. Ces enzymes catalysent la réaction de transformation de molécules du bois en molécules d'intérêt organoleptique (comme la vanilline) [3]. Ainsi, une meilleure connaissance du développement et de la composition de ces biofilms est importante afin de mieux maitriser le processus de fabrication du vin. The concentration of the different co-existing or linked species is particularly dependent on the temperature, acid and alcohol content of the wine. Interaction with the wine sample during the analytical procedure itself could influence the results, for both the direct (chromatography, colorimetry, iodometry) and indirect (steam distillation, titrimetry) methods. None of them provides a universal panacea: In some of them, interferences could bias the results, in others, the experimental conditions are so rigid that it is difficult to control and reproduce them correctly (robustness). Even the official method by Franz-Paul (RCE 2676/90, OIV-MA-AS323-04A) is not always clear or precise enough, and leads to confusion or inconsistency between laboratories, especially for the determination of the free form of SO 2 . Agroscope tested the influence of various analytical parameters on the SO 2 results and presents some recommendations, particularly with regard to the temperature of the samples during analysis. Keywords: Saccharomyces cerevisiae; redox balance; wine fermentation; aroma compounds Wine alcoholic fermentation is a complex and dynamic process in which the yeast is subjected to multiple stress conditions. Saccharomyces cerevisiae wine yeast strains have been selected from the environment for specific technological traits such as high fermentation rate and formation of metabolites. Redox homeostasis is a fundamental requirement for sustaining metabolism. The objective of this work is to gain a better understanding of the effect of the redox balance on the synthesis and regulation of volatile metabolites that contribute to the sensory profile of wine. The important molecules include esters, higher alcohols, volatile fatty acids and volatile sulphur compounds.

EFFECTS OF REDOX PERTURBATION ON THE SYNTHESIS OF FERMENTATIVE

To study how the aroma network responds to redox perturbations, we used yeasts overproducing a native NADH-or engineered NADPH-dependent butanediol dehydrogenase catalyzing the reduction of exogenous acetoin into 2,3-butanediol (Ehsani et al, 2009). We found that an increased NADH or NADPH oxidation markedly changed the production of fermentative aroma. Surprisingly, changes in the NADPH demand triggered a similar but weaker response, suggesting inter-conversions between NADH and NADPH cofactors. The production of volatile compounds from Ehrlich pathway in response to increased NADH showed different profiles depending on the leucine or valine pathway degradation, suggesting different metabolic controls. Moreover, a combined increase in the synthesis of propanol and its derived acid and esters was observed with an increased NADH demand, consistent with a redirection of carbon flux towards threonine formation. Changes in the ethyl esters profile was also observed as a result of modifications of NADH and NADPH oxidation, in line with a decrease in the synthesis of their precursors that involves NADPH-consuming reactions (fatty acids).

"Le vigneron et le processus d'élaboration du vin, une approche ethnologique"

Véronique BOIDRON

Anthropologue Session 2 oral

Je me propose d'exposer, grâce aux méthodes d'enquêtes ethnologiques, une approche inédite du processus d'élaboration du vin centrée sur le vigneron et son univers de travail. D'un point de vue diachronique, les principes oenologiques ont peu à peu pénétré cet univers durant la deuxième moitié du XX e siècle, permettant notamment d'améliorer les qualités gustatives du produit et de répondre à des normes sanitaires, légales, commerciales, etc. Cela s'est traduit par le développement d'une maîtrise technique autour du vin, mais également par l'arrivée de l'oenologue qui a peu à peu investi cet univers. Or aujourd'hui, face aux apports des innovations techniques et des découvertes scientifiques dont l'oenologue est un des vecteurs essentiels, certains vignerons mobilisent des savoirs et des savoir-faire qui empruntent au registre de l'empirisme et de l'expérimentation, mettant ainsi à distance des procédés qu'ils jugent trop technologiques. Se pencher sur les représentations singulières associées à ces pratiques permet de saisir les « liens » qui unissent le vigneron à son produit. Dans cette approche que le vigneron qualifie parfois lui-même d'instinctive, et qui peut d'emblée paraître irrationnelle, se révèle en fait un mode de pensée où le vin est conçu dans un processus réciproque de création, en lien étroit avec le travail à la vigne, les caractéristiques du terroir ou des parcelles, le ressenti, la personnalité et l'histoire du vinificateur : ce dernier crée le vin, mais en retour le vin initie et façonne le vigneron et ses savoirs au fil des millésimes. Ainsi, en marge de la conformation à des normes sociales et à des pratiques techniques incontournables, ces façons de penser et de faire le vin traduisent, pour ces vignerons, une volonté de réappropriation et de maîtrise tant au niveau des procédés d'élaboration que du goût du vin, mais elles reflètent aussi une façon de concevoir leur métier centrée sur une relation intime et forte à la nature, à la vigne et au vin. There are increasing evidences [1,2] indicating that some wine aroma compounds form complexes or adducts with different matrix elements, which can deeply affect to their real distribution to the headspace and hence to the aroma perception. The process can be schematized as: Aroma gas ↔ Aroma liquid ↔ Aroma complexed In wine these effects are particularly important for carbonyls which form adducts with SO 2 [3]. In spite that the existence of bisulfite adducts between SO 2 and carbonyls was documented long time ago, and in spite of the fact that some carbonyls, namely methional, phenylacetaldehyde, diacetyl and β-damascenone are amongst the most important aroma compounds of wine (the two first responsible for wine aroma oxidation [4]), there are not reports or tools regarding their measurement of their free and complexed forms.

Mots clés

Twenty-four wines saturated with air were stored at 25 °C in an incubator. When they consumed this oxygen or a week later they were analyzed and re-saturated. This process was repeated five times. Every day the oxygen consumption was controlled with Nomasese oxygen meter. Analyses carried out were free and bonded carbonyl compounds, free and total SO 2 , colour, total polyphenols index, and redox potential. In order to have more information about the formation of carbonyl compounds amino acids and alcohols have been analyzed in the original sample and in the final step.

The simultaneous determination of free and bonded carbonyl compounds is based on a HS-SPME-GC-MS method using standards which provide constant headspace concentrations not dependent on the wine and are used to estimate concentrations of analytes in the headspaces (free fractions), and surrogates that behave similarly to the analytes and their relative signals to those of the standards are used to estimate the proportion in bonded form.

The method provides that sensory changes are due from a combination of their release from their complexes with sulfur dioxide and to the "de novo" formation of carbonyls.

Funded by the Spanish Ministery of Economy and Competitiveness (Project AGL2010 230183). In the present work a stilbene extract (STE, provided by ACTIchem, Montauban, France) was used as an alternative to SO 2 in microvinifications. Sauvignon blanc and Syrah varieties were selected for the assay. Phenolic profile, antioxidant activity and olfactometric profile were determined in wines elaborated with both, stilbene extract and SO 2 . The results show no significant differences in the parameters related to wine quality (pH, total acidity, organic acids, potassium, IPT, IFC), neither in color-related parameters (color intensity, hue, CieLab*) and sensory. Moreover, acetaldehyde content was lower in white wines elaborated with STE than that elaborated with SO 2.

BIOACTIVE STILBENES AS ALTERNATIVE TO SULPHUR DIOXIDE IN WINEMAKING

The results suggest that the use of stilbenes for replacing SO 2 in wine is feasible. Additionally, pharmacological properties of stilbenes support the use of these compounds as complementary nutritional molecules, and therefore the increase of stilbene content in wine gives it an added-value. Many authors dealt with the concept of wine quality. Generally, based on prior literature, quality can be defined from four different points of view: as excellence or superiority; as value; as conforming to specifications; and as meeting or exceeding customer expectations [1]. In addition, in the case of a Protected Designation of Origin (PDO) wine, the global quality has to be integrated by one more point related to the typicity defined as a set of properties of belonging and distinction [2]. These properties are expressed by sensory attributes which are related to the specific area, raw material and winemaking process [3]. In this study, the concept of quality is the outcome of the combination of eligible characteristics, which meet the needs of the globalized market and which are common to all wines (such as acidity, astringency, viscosity, etc..) characteristics and peculiarities (or identity), which reflect the territorial implications of the product (eg, floral aromas, fruity, etc). Given these considerations, this study has introduced a new methodological approach in which, starting from the identification of wine samples representative of a PDO area, a sensory profile has been defined and the related chemical markers identified. This has allowed the definition of eligible and peculiarity profiles. These profiles represent tools for the control and optimization of the winemaking process which, starting from an eligible and a peculiar raw material, allow to obtain a wine with predefined characteristics. The study was carried out during three consecutive harvests (2009, 2010 and 2011).

White wine presents a pool of fluorescent materials including a large class of families (polyphenolics, vitamins and amino acids). They can evolve independently upon ageing or interact each other and with other fluorescent macromolecules such as proteins. Each molecule is described by a set of excitation/emission wavelength. Therefore, excitation emission matrices (EEMs) have been well used in the description of wine compounds [1]. EEMs can be viewed as genuine fingerprints of molecular and macromolecular composition in wines. In order to describe EEMs, a trilinear decomposition model, PARAFAC [2], is applied to resume the matrix by a fixed number of components that can be related to single or several fluorophores. Such chemometrics has been applied to determine differences in origins and grape varieties of red wines [3]. Fluorescence measurements were performed in a set of white wines with different evolution stages. EEMs were obtained and treated with the parallel factor analysis (PARAFAC) to describe the evolution of fluorescent compounds upon ageing.

Results indicated that 3 components, C1, C2 and C3 could explain the differences of all of the matrices with a very good core consistency of 81 %. Email: cook0278@umn.edu Synthesis of berry anthocyanins takes place in a mature organ with an organized arrangement of specialized tissues. 1In teinturier (dyer) varieties of grapes, it is known that anthocyanin synthesis is activated in cells across much of the berry tissue. The mature berry of 'Frontenac' (V. riparia x Landot 4511), is entirely red and has thus been classified as a teinturier grape. 'Frontenac Gris', which arose from a single-bud mutation of 'Frontenac', has an apparent colorless pulp. Nonetheless, the juice color following direct-pressing of 'Frontenac Gris' is often pink, which can result in a wine with an undesirable dark amber to orange color. We removed a 2-mm wide cross-section from both 'Frontenac' and 'Frontenac Gris' and examined them with an epifluorescent microscope. We found that while both varieties contain anthoycanin inclusions in the epidermal cells, they do not contain specialized organs for anthocyanin synthesis in the cells located beneath the epidermis. Nonetheless, red pigment appears within the cytoplasm of these cells in both cultivars. We thus propose that a passive transport mechanism for anthocyanin exists in these varieties. In addition, we looked at the thickness of the cell wall, the number of pores, and the cuticle thickness of these cultivars in order to compare these anatomical features to other cultivars with known resistance to Botrytis cinerea. 2 Current research on novel stilbenoid compounds in these varieties may elucidate further knowledge into their pathogen resistance.

L'éthanal, molécule clef de la stabilité des vins Adrien DEBAUD, Nicolas MARCHET, Caroline BONNEFOND et Daniel GRANÈS

Groupe ICV, La Jasse de Maurin, 34970 Lattes, France Téléphone : +33 466 647 082 Fax : +33 466 238 497 e-mail : adebaud@icv.fr Mots clés : éthanal, SO2, levure, bactérie lactique Le Groupe ICV réalise depuis 2010 le dosage de l'éthanal (ou acétaldéhyde) sur les vins, par voie enzymatique. La méthode originale de dosage que nous avons développée et que nous présentons ici s'appuie sur un mode alternatif de préparation des solutions d'étalonnage, mettant en oeuvre une poudre, l'acétaldéhyde ammonia trimer plutôt que la forme liquide, très volatile à température de laboratoire. La stabilité de ces étalons garantit davantage de justesse et diminue en outre les risques d'exposition à l'éthanal liquide pur, difficile à manipuler et toxique. Nous nous sommes appuyés sur plus de 600 analyses chimiques de vins de tout type à différents stades de leur production pour réaliser une exploitation statistique des liens entre éthanal et SO2, permettant de s'affranchir dans la quasi-totalité des situations du dosage des combinants secondaires du SO2 tels que l'acide pyruvique et l'alpha-kétoglutarate. Un modèle prédictif du niveau de SO2 libre, issu de ces travaux, exploitant ce dosage de l'éthanal a été développé. Il permet au vinificateur de quantifier l'addition à réaliser en fonction de son objectif de SO2 libre.

Au-delà de cet outil de calcul, le dosage de l'éthanal apporte des informations précieuses au cours de toutes les étapes de la vinification : la molécule est en effet largement impliquée dans des voies biochimiques de production / consommation levurienne et bactérienne, et est un indicateur des pratiques de gestion de l'oxygène et du SO2 en cave. Notre étude a permis de confirmer la cinétique de production pendant la fermentation alcoolique ainsi que le rôle des bactéries lactiques dans sa consommation lors de la fermentation malo -lactique.

Nos travaux élargissent cette approche globale sur les liens entre SO2, éthanal, oxygène dissous, polyphénols, levures et bactéries, en intégrant également la recherche de voies de consommation ou de combinaisons possibles et exploitables de l'éthanal avec d'autres composants du vin.

Brettanomyces bruxellensis is a well-known spoilage yeast in red wine. A number of antimicrobial compounds can be used to prevent or eliminate the undesired growth of B. bruxellensis. These include sulphur dioxide, dimethyl dicarbonate and chitosan. The use of inactivated ozone, pulsed electric fields, UV radiation has also been proposed. Recently, the use of a cocktail of β-glucanases was also proven to result in the inhibition of B. bruxellensis growth. In this context, a few authors have suggested the use of killer toxins secreted by an array of non-Saccharomyces yeasts. The nature of most of these toxins remains unclear today, but they could be cell wall enzymes. However, although the toxins considered in these studies have been shown to display killer activity against B. bruxellensis, their native producers did often not originate from the wine environment.

In the current study, non-Saccharomyces yeasts isolated from grape juice were screened for killer activity against B. bruxellensis. Two isolates exhibited strong activity and their killer toxins were further characterised. Their killer property was confirmed against various yeast species and strains. The toxins were shown to display a stronger activity on grape juice than on YPD medium. This phenomenon was further investigated. Activity and stability over a range of pH and temperature were tested and revealed the compatibility of these toxins with winemaking conditions. The killer activity of these toxins was also assessed in the presence of varying concentrations of glucose and ethanol in order to determine at which stage of the winemaking process these toxins were active. Overall, our study shows the isolation of two novel killer toxins secreted by wine non-Saccharomyces yeasts with strong potential as biopreservatives against B. bruxellensis. Future work includes the purification of these toxins and their identification at genetic and protein levels. Fining consists in the addition of certain substances to wine that are capable to promote flocculation and sedimentation of undesired components. This practice is essential for the wine final quality, since it improves limpidity, stabilisation and organoleptic balancing. The fining agents available on the market are mainly composed by animal proteins as casein, caseinates, gelatin or egg albumin. However, due to their potential risk on the consumers' health, recent European legislations have already been adopted and particularly, the use of milk proteins will soon need to be declared on the wine labelling. Therefore, innovative, biologic and non-allergenic alternatives should be further investigated.

In this project, our objective is to identify and develop alternative fining agents, obtained from a natural source, already present in wine -oenological yeasts. Indeed, we have already identified two specific yeast protein extracts with the capacity to simultaneously improve white wine clarification and stabilisation. These potential fining agents present similar effects when comparing to other commercial products in terms of both final brilliance and limpidity. Additionally, they were able to cause a smoother reduction of specific polyphenolic compounds and, interestingly, to accentuate the wine varietal aroma and organoleptic balance. Currently, we are further investigating the impact of those fining agents in terms of long-term stabilisation and testing the process up-scalling, to effectively evaluate their potential industrial use. Altogether, in this work we have shed new light on the application of yeast proteins for white wine clarification and stabilisation. Moreover, this work is important to overcome the health concerns, related with the use of allergenic animal proteins. This study arises from the need to recover by-products of winemaking that can still provide wine active compound as tannins, aromas and polysaccharides 1 . The alternative management of lees proposed in this study also reduces the amount of by-product to be disposed. The tests were carried out in 2012 at a winery in the Chianti area. An extraVelvet 1.0 system was used for the treatment of total lees. The extraVelvet 1.0 is a steel macerator equipped with scrolls and an automatic temperature control system. Wine on lees (10% v/v) was maintained at 22 °C and resuspended every two days for 30 min. Samples were taken every 15 days until two months of treatment. Colour, total polyphenol, phenolic fractions, copigmentation index do not change significantly during the treatment. After only one month of treatments, a significant increase of total polysaccharide was observed. The Gelatin Index as well as the Astringency Mucin Index (AMI) 2 decrease indicating that polyphenols are become progressively less reactive towards proteins. Total proteins significantly decrease and the amount of αamino nitrogen do not change in treated wines. No flavour deviations were detected.

The obtained results showed that the proposed treatment of lees can contribute to the rapid extraction of compounds involved in the characteristic of astringency, body and structure of wine as well as in the colour stability. Wine quality and its stability during secondary shelf-life (after bottle opening) is often central to consumer acceptability. Despite care in preserving wine quality during production and bottling, oxidative changes after opening are difficult to avoid, and can negatively impact on sensory character [1,2]. While literature on wine oxidation exists, few studies have investigated how wines change after opening, especially due to limitations still existing in reliable instruments for accurate and high-throughput measurements. In this study chardonnay wines from different geographical origins were evaluated by non-volatile and volatile profiling directly after opening and during six weeks of storage. Chardonnay wines were obtained from France, Chili, Australia, South Africa, Argentina, Brazil and New Zealand. Phenolic acid and volatile profiles were assessed by high pressure liquid chromatography (HPLC) and rapid proton transfer reaction mass spectrometry (PTR-MS) respectively. Measurements of total acidity, pH and total polyphenol content were also recorded. Chemometric analysis of phenolic acid profiles and volatile finger-prints allowed for promising classifications of chardonnay wines by geographical origin and could be applied to observe chemical changes during six weeks of storage after opening. This objective analytical characterization of wine could help verify the wine origin and substantiate its change in quality after opening. Sulfite is a widely used preservative in food industry. It prevents oxidation and bacterial growth [1]. Sulfite content has a considerable effect on wine quality. For this reason its determination is of vital importance [2]. Biosensors offer a simple, sensitive and selective alternative for the classical sulfite determination methods (e.g. gas chromatography, acid-base titration). A widespread approach in this field is the use of sulfite oxidase enzyme based electrochemical sensors. Utilizing this enzyme in bioanalytical tools, sulfite detection is based on measuring the oxidation current of sulfite, or that of hydrogen peroxide, which is formed during the enzymatic reaction [3].

Our aim was to develop a novel sulfite oxidase based amperometric biosensor for the determination of sulfite in wines. As this enzyme is currently not available commercially, the first phase of the work was the isolation and purification of sulfite oxidase from chicken liver. We modified the isolation published by Kipke et al. (1989) [4]. Fresh liver was chopped and homogenized in chilled acetone, and then with acetone and ether. The "filter cake" obtained was dried ("acetone powder"), and extracted with buffer. It was followed by two precipitation steps with ammonium sulfate. The sample was dialyzed against a buffered solution containing sodium molybdate, before the ionexchange chromatography step (Armen Spot Flash LC, Macro-Prep High Q cartridge).

After each phase, samples were taken, and the enzyme activity and protein content were measured photometrically. Using this method, 20 fold purification was achieved. Also, extensive work was carried out to develop a measuring setup for the selective measurement of sulfite and hydrogen peroxide, utilizing screen printed carbon electrodes.

Mots clés : résidus, adsorbant, filtration

Les teneurs en résidus de produits phytosanitaires dans le vin, même très largement inférieurs aux limites maximales de résidus (LMR) fixées sur raisin, restent une préoccupation de plus en plus croissante des consommateurs. Face à cette demande du marché, un produit ADFIMAX® (www.adfimax.com) a été développé par un consortium 1 Ce produit adsorbe de façon sélective les toxines et polluants présents en très faibles quantités dans le vin. L'usage prévu du produit se fait lors de la filtration des vins, en filtre presse ou filtre avec alluvionnage à 1 kg/m², ou incorporé dans une plaque de filtration. Cet adsorbant est particulièrement innovant car il est produit à partir de fibres d'origine végétale.

de PMEs et centres de recherche au cours d'un programme de recherche européen.

Le produit a été testé à échelles laboratoire et pilote, dans différents modes d'utilisation (plaque ou en adjuvant de filtration). Le produit a aussi été comparé au charbon et à une plaque de filtration spécifique. Les paramètres suivants ont été évalués sur vins : suivi de filtration, analyses physico-chimiques, teneur en pesticides, évaluation sensorielle. La capacité filtrante du produit a été démontrée, de même que l'absence d'impact sur les paramètres oenologiques classiques. Les analyses des teneurs de pesticides du vin filtré montrent une réduction de la teneur du vin final de l'ordre de 90 % pour le dimétomorphe, boscalid, iprodione. Les pesticides ont été détectés à très haute concentration dans le gâteau de filtration, confirmant la capacité du produit à adsorber spécifiquement ces molécules.

Cette innovation a fait l'objet d'une demande d'autorisation d'expérimentation en

France et d'une évaluation selon les codes Food and Drug Administration (FDA) en Allemagne. Les démonstrations en grands volumes débuteront en janvier 2014 afin de confirmer ces résultats en conditions réelles.

The project aims to study the metabolic interaction between yeasts and malolactic bacteria. In the winemaking practice, phenotypes of commercial S. Cerevisae strains can be categorized according to whether they stimulate or inhibit the malolactic activity of bacteria. The assumption is that yeast strains, giving birth to diverse metabolic footprinting or exo-metabolome [1], could alter the bacterial metabolism in different ways. Therefore a sequential culture strategy was used: cell-removed media fermented by different yeast strains will be used to start malolactic fermentation (MLF). Meanwhile the metabolic profile of stimulatory strains was compared to less stimulatory ones by studying yeast-fermented media with non-targeted technics (ICR/FT-MS and UPLC-MS). The non-targeted approach was chosen for its ability to provide in a single run, representations of the thousands of compounds that could be involved in yeast-bacteria interaction [2]. The results highlighted two different yeast phenotypes, and chemical compounds discriminating the two phenotypes could be identified as potential biomarkers of interaction with powerful statistical tools. Their structure will be validated by UPLC-MS/MS fragmentations. The exact influence of these biomarkers to the bacterial metabolism will be studied by looking at the kinetics of the exo-metabolome of malolactic bacteria during MLF. The concentration evolution of selected compounds will be used to parametrize a metabolic network model [3]. All of these approaches will improve our knowledge on the impacts of yeast on the metabolic pathways of bacteria. Earlier studies stated that yeast extracts could have a potential to clarify red wines [1][2][3] without giving details of the influence of these fining procedures on the sensory profile of the wines.

YEAST PROTEIN EXTRACTS AS AN ALTERNATIVE TO CLASSICAL FINING AGENTS FOR RED WINES

Yeast strains of the genus Saccharomyces were selected in this study that showed autolysis when exposed to stress conditions. The selected yeast strains enabled the production of protein extracts by autolysis. Proteins of the extracts had defined fractions of molecular mass above 10 kDa detected by SDS-PAGE which was not demonstrated in the studies mentioned above. These extracts with a low degree of hydrolysis were successful in clarification of red wines. Turbidity and colour intensity of the wines were influenced by fining with yeast extracts in a similar way to wine fined with gelatine used as a reference. Sensory analysis by experienced tasters revealed no meaty notes, characteristic of standard yeast extracts [4,5], in the wines after fining with the yeast products.

Since yeast protein extracts are now permitted in the European Union (regulation (EU) No 144/2013) it offers a new category of fining products to the wine makers.

Key words: yeast protein fining

  ANTALICK a,b# , Marie-Claire PERELLO a,b , Gilles DE REVEL a,ba: Université de Bordeaux, ISVV, Villenave d'Ornon, France b: INRA, ISVV, USC 1219 oenologie, Villenave d'Ornon, France #present address: National Wine and Grape Industry Centre-Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia Telephone: +61 2 6933 4821 Fax: +61 2 6933 4821 Email: gantalick@csu.edu.au Key words: esters, wine aroma, wine ageing, yeast metabolism

  AROMA DURING ALCOHOLIC FERMENTATION Audrey BLOEM a,b,c , Sylvie DEQUIN a,b,c , and Carole CAMARASA a,b,c a : INRA, UMR1083 Sciences pour l'oenologie, Montpellier, France b : SupAgro, UMR1083 Sciences pour l'oenologie, Montpellier, France c : Université Montpellier I, UMR1083 Sciences pour l'oenologie, Montpellier, France Corresponding author: Audrey BLOEM, audrey.bloem@univ-montp1.fr UMR Sciences pour l'oenologie 2 place Viala 34060 Montpellier Cedex 02 France Tel: +33 (0)4 99 61 20 54 Fax: +33 (0)4 99 61 28 57

  Lochbühler a , Sébastien Manteau b , Christophe Morge b , Marie-Madeleine Caillet b , Claudine Charpentierc , Manfred Grossmann a , Doris Rauhut a a Hochschule Geisenheim University, Department of Microbiology and Biochemistry, Von-Lade Str.1, 65366 Geisenheim, Germany, b.lochbuehler@hs-gm.de, tel. 0049 6722 502 331, fax 0049 6722 502 330 b SOFRALAB SAS, 79, av. A.A. Thévenet, 51319 Epernay, France c former address : Université de Bourgogne, Institut Universitaire de la Vigne et du Vin "Jules Guyot", Rue Claude Ladrey, 21078 Dijon, France According to regulation (EU) No 579/2012 of the European Union the use of traditional fining agents derived from egg or milk in must or wine has to be declared towards the consumer if detectable protein traces remain in the product. This has encouraged the search for alternative protein sources, like plants or yeasts that are not regarded as allergenic by European law (regulation (EU) No 1169/2011).

SO 2 IN WINE: MULTIPLE SPECIATION, MULTIPLE METHODS, AN ANALYTICAL HEADHACHE Sandrine BELCHER a , Frédéric VUICHARD, Sévan KUYUMKUYAN

  Traditionally SO 2 has been added to wine as an antimicrobial and stabilization agent. Since the 25 th of November 2005 European legislation has mandated the systematic declaration of wines containing more than 10mg/l of sulfite. But how is this amount really determined in practice and with what accuracy? The problem is that SO 2 undergoes multiple reactions in wine, combining with a number of other compounds.

	a Agroscope, route de Duillier 50, Case postale 1012, 1260 Nyon 1, Switzerland ;
	Tél. +41 22 363 43 36, Fax +41 22 362 13 25, E-mail: sandrine.belcher@agroscope.admin.ch
	Keywords: Sulfite, analytical conditions, Franz-Paul, temperature,

Après avoir analysé les propriétés d'adhésion et la cinétique de développement des souches de O. oeni, notre étude se focalise sur l'analyse chimique des exopolysaccharides, par spectroscopie infra-rouge pour caractériser la structure chimique à la surface et par chromatographie pour identifier les unités monomériques.

OXIDATIVE BEHAVIOUR IN DIFFERENT WINES USING SIMULTANEOUS DETERMINATION OF FREE AND BONDED VOLATILE CARBONYLS Mónica BUENO a , Ernesto FRANCO-LUESMA a , Vanesa CARRASCÓN a and Vicente FERREIRA a

  : vigneron, vin, savoir, représentation

	E-mail: mobueno@unizar.es	phone number: +34 876 55 33 28

a Laboratory for Flavor Analysis and Enology. Department of Analytical Chemistry, University of Zaragoza, 50009 Zaragoza, Spain. Aragon Institute for Engineering Research (I3A).

Rafaela RAPOSO a , María José RUIZ-MORENO a , Belén PUERTAS a , José Manuel MORENO- ROJAS a , Pilar ZAFRILLA b , Juana MULERO b , Emma CANTOS-VILLAR a

	a Instituto de Investigación y Formación Agraria y Pesquera (IFAPA) Consejería de Agricultura, Pesca y
	Desarrollo Rural (Junta de Andalucía). Ctra Trebujena, km 2.1, 11471, P.O. Box 589 Jerez de la
	Frontera, Spain. Phone (34)671560353; fax (34)956434610
	c Universidad Católica San Antonio (UCAM), Campus de Los Jerónimos, s/n Guadalupe. 30107. Murcia,
	Spain
	e-mail: emma.cantos@juntadeandalucia.es

Keywords: stilbenes, antioxidant, sulphur dioxide, quality wine ABSTRACT Sulphur dioxide (SO 2 ) is one of the most versatile and efficient additives used in winemaking due to its antiseptic and antioxidant properties. However, due to the healthrelated problems that have been associated with SO 2 use, it uses has progressively reduced in winemaking.

THE DEFINITION OF WINE QUALITY PROFILES AS START POINT TO OPTIMIZE THE WINEMAKING PROCESS

	Valentina CANUTI, Monica PICCHI and Mario BERTUCCIOLI
	GESAAF -Dipartimento di Gestione dei Sistemi Agrari, Alimentari e Forestali, Università degli Studi di
	Firenze, Firenze, Italy. Via Donizetti, 6 -50144 Firenze, ph.+39 0553288465, fax.+39 0553288488.
	E-mail: valentine.canuti@unifi.it
	Key words: wine quality, typicity, winemaking process

ANATOMICAL FEATURES OF BOTRYTIS CINEREA RESISTANT GRAPE BERRIES, 'FRONTENAC' AND 'FRONTENAC GRIS' Kathryn COOK, Chengbin CHEN, James LUBY University

  Topic of the Conference: Active compounds and enological Processes Preference: Poster presentation of Minnesota, Department of Horticultural Sciences, St. Paul, Minnesota USA 1970 Folwell Avenue, St. Paul, MN 55108 USA. Phone 1.952.443.1503 Fax 1.612.624.4941

  CHARACTERISING CHARDONNAY WINES FROM DIFFERENT ORIGINS AND AFTER OPENING USING NON-VOLATILE AND VOLATILE PROFILINGSamuel. P. Heenan a,b* ., Simon. Ginggen a,c ., Umberto Piantini c ., Saskia. M. van Ruth a,c

	a RIKILT Wageningen UR, P.O. Box 230, 6700 AE Wageningen, the Netherland
	bc Food Quality and Design Group, Wageningen University, P.O. Box 8129, 6700 EV Wageningen, the
	Netherlands
	c University of Applied Science HEVs, 1950 Sion, Switzerland

Metabolic profiling of grape canes stilbenoids in grape varieties grown in the Loire valley. Houille B 1 , Delanoue G 2 , Boudesocque L 3, Courdavault V 1 , Besseau S 1 , St-Pierre B 1 , Courtois M 1 , Enguehard-Gueiffier C 3, Giglioli-Guivarc'h N 1 , Guerin L 2 , Lanoue A 1

  Grape canes a non-recycled waste of wine industry (1-5 tons per hectare per year) may have considerable potential as a source of bioactive compounds, especially resveratrol oligomers and other polyphenols. Resveratrol and wine polyphenols are known to exert health-promoting effects including antioxidant capacity, cardioprotection, anticancer activity, anti-inflammatory effects, and estrogenic/antiestrogenic properties[START_REF] Guerrero | Wine, Resveratrol and Health: a Review[END_REF]). Additionally, resveratrol is a major phytoalexin produced by plants in response to various stresses and promotes disease resistance[START_REF] Chang | The Phytoalexin Resveratrol Regulates the Initiation of Hypersensitive Cell Death in Vitis Cell[END_REF].

	1 Biomolécules et Biotechnologies Végétales, EA 2106, Université François-Rabelais de Tours, France, 2
	Institut Français de la Vigne et du Vin, Tours, France, 3 UMR INRA 1282 ISP, Equipe Innovation en
	Chimie Médicinale, Université François-Rabelais de Tours, France.
	arnaud.lanoue@univ-tours.fr
	Keywords: grape canes, resveratrol oligomers, metabolic profiling.
	Resveratrol oligomers were obtained by purification using Centrifugal Partition
	Chromatography followed by preparative Thin Layer Chromatography and
	semipreparative High Pressure Liquid Chromatography. Dimers (Ampelopsin A, t-ε-
	viniferin), trimer (Miyabenol C) tetramers (Hopeaphenol, Isohopeaphenol and Vitisin
	B) of resveratrol were purified and the structures were confirmed by 1 H-and 13 C-NMR Key Words: Wine origin, shelf-life, phenolics, volatiles spectroscopy. The metabolic profiles of grape canes from various grape varieties grown
	in the Loire valley (Côt, Cabernet franc, Sauvignon and Gamay) were analyzed by Ultra
	High Pressure Liquid Chromatography coupled with Mass Spectrometry and Diode
	Array Detection. Multivariate statistical analyses highlighted biomarkers of each grape
	variety.

Falginella, L., G. Di Gaspero, S.D. Castellarin.

Expression of flavonoid genes in the grape berry of 'Alicante Bouschet' varies with the histological distribution of anthocyanins and their chemical composition. Planta 236:1037-1051 2 Gabler, F.M., J.L. Smilanick, M. Mansour, D.W. Ramming, B.E. Mackey. 2003. Correlations of Morphological, Anatomical, and Chemical Features of Grape Berries with resistance to Botrytis cinerea. Phytopathology 93:1263-

RELEASE OF COMPLEXED VOLATILE SULFUR COMPOUNDS UNDER REDUCTIVE CONDITIONS

Ernesto FRANCO-LUESMA a , Mónica BUENO a , Vanesa CARRASCÓN a and Vicente FERREIRA a a Laboratory for Flavor Analysis and Enology. Department of Analytical Chemistry, University of Zaragoza, 50009 Zaragoza, Spain. Aragon Institute for Engineering Research (I3A).

E-mail: efranco@unizar.es phone number: +34 876 55 33 28

Volatile Sulfur Compounds (VSCs): MeSH (methanethiol), EtSH (ethanethiol), DMS (dimethylsulfide), DES (diethylsulfide), DMDS (dimethyldisulfide) and DEDS (diethyldisulfide) together with hydrogen sulfide (H 2 S) show similar sensorial characteristics described as rotten eggs and cabbage [1]. These compounds usually appear during bottle aging giving rise to problems commonly defined as "reduction". The origin of this problem is so far not known. In this work we investigate the existence of complexed non-volatile forms of these compounds which may be ultimately responsible for their release upon the reductive conditions usually found in a wine bottle.

Twenty-four wines have been incubated under a zero oxygen atmosphere, the oxygen level was controlled by an oxygen meter from Nomasense, and all the samples were prepared in a glove box from Jacomex with oxygen levels under 5 ppm. VSCs, colour, total polyphenols index, free and total SO 2 , redox potential, major and trace compounds, aminoacids, and metals have been measured. VSCs were analized by two procedures, one that quantifies the total amount and the other which measures the free VSCs concentration (headspace concentration). Both VSCs methods have provide us information about the release of mercaptans in bottle conditions for a wide range of wines.

All these data have allowed us to understand reductive processes, mainly the release of H 2 S and DMS, in many different wines with several behaviors under reductive conditions, which represents an important knowledge in order to try to avoid the reduction of the wine when is in the bottle. Key words: Ascorbic acid, Sulfur dioxide, Glutathione, Xanthylium pigments, Oxidation

PRINCIPAUX COMPOSÉS BIOACTIFS DE VINS ROUGES EN RAPPORT AVEC L'ORIGINE GEOGRAPHIQUE DES RAISINS ET LA VINIFICATION

During the whole vinification process wine compounds take part in chemical reactions that affect the sensory properties. The mayor catalyst for these reactions is oxygen, which is especially damaging white wines. So called antioxidants such as ascorbic acid, sulfur dioxide, and glutathione are used to prevent oxidation. The effects of these antioxidants on the oxidative evolution of wine-like systems containing (+)-catechin and metal ions have been compared by monitoring O 2 consumption, color evolution by CIELab, as well as (+)-catechin and glutathione decrease by LC-DAD/FD. The oxidation product formation especially the degradation of tartaric acid and the subsequent formation of yellowish colored Xanthylium compounds [1,2,3] was investigated by LC-ESI-ToFMS. The results show that the Xanthylium cation formation is favored compared to the proanthocyanidin formation. The addition of sulfur dioxide does not prevent the oxidation of tartaric acid to glyoxylic acid but slows down Xanthylium formation. Using a model system free of tartaric acid Xanthylium cation formation could be observed by ascorbic acid addition resulting in a color shift towards yellow -green and the formation of an unknown peak. Glutathione addition could prevent Xanthylium cation formation but not the (+)-catechin decrease probably due to glutathionyl-(+)-catechin adduct formation. The same system with tartaric acid showed that both sulfur dioxide and ascorbic acid could reduce oxidative color changes and Xanthylium cation formation with sulfur dioxide providing the best protection. The addition of glutathione leads to significant increase in Xanthylium formation and a green -yellowish color and could not inhibit carboxymethine-bridged (+)-catechin dimer formation. In comparison to the other investigated antioxidants glutathione is not able to impede oxidative color evolution.

IMPACT OF PRESS FRACTIONING ON PINOT MEUNIER GRAPE JUICE COMPOSITION

Richard MARCHAL 1 , Thomas SALMON

Keywords

Grape juice composition, Pinot meunier, press fractioning, proteins, electrophoresis.

Contribution

The separation of different grape juice press fractions is an important step in the production of sparkling base wines. A complete press cycle for this style of wine is a series of pressure increases resulting in a considerable variation in juice composition during the press cycle (1, 2, 3). After alcoholic fermentation, wines obtained from Cuvées (C) and Tailles (T) grape juices also exhibit strong differences for numerous characteristics [1].

Nevertheless, the impact of the press cycle on wine proteic fraction, largely implicated in wine foaming properties, has never been studied with healthy and Botrytis contaminated grape berries. The aim of this study, carried out on Pinot meunier, was to gain a greater understanding of 1) must composition changes all along the 3h30 press cycle (current analyses), 2) differences in grape juice composition (especially protein content) according to the presence or the absence of rotten bunches (laboratory press), 3) correlation between two grape juice compositions obtained with a 8.000 kg pneumatic press and a 6 kg traditional press. Protein content, as investigated by SDS-PAGE and silver nitrate staining, shows significant changes in protein levels as the pressing progressed. An increase of the protein content is noted during the two first cycles, followed by a regular decrease during the four last cycles. After SDS-PAGE, 9 bands were isolated and studied by LC-MS + Mascot as Search Engine. Identified proteins originated from Vitis vinifera with MW ranging from 20 to 64 kDa. The Vitis vinifera proteins are : class IV chitinase, VVTL1, thaumatin-like protein, putative thaumatin-like protein and several putative uncharacterized proteins. For some of these proteins, the concentration was not the same in the press juice and in the return juice where a decrease is observed. Key words: biogenic amines, amperometric biosensor, diamine oxidase enzyme Biogenic amines are low-molecular-weight, nitrogen-containing compounds of biological importance in vegetable, microbial and animal cells. Although they are essential to living organisms, consumption of food containing high amounts of them may have toxicological effects. Considerable amounts of biogenic amines may accumulate in fermented foods like wine. However, the concentration of biogenic amines in wines is highly variable. It depends on conditions like hygiene, temperature, pH and strains used during fermentation. For this reason, the measurement of biogenic amines provides vital information concerning food safety. [1] The aim of our work was to develop enzyme based amperometric biosensors for the determination of biogenic amines in wine samples. Diamine oxidase (DAO, EC 1.4.3.6) from Pisum Sativum reacts with the most important biogenic amines which can be found in wine, so the total biogenic amine content could be determined with the DAO biosensor. The enzyme was immobilized on the surface of a graphite electrode in redox hydrogel with horseradish peroxidase, Os mediator and poly(ethylene glycol) (400) diglycidyl ether (PEGDGE) as crosslinker. This modified working electrode was used in wall-jet type amperometric cell together with the Ag/AgCl (0.1 M KCl) reference electrode and a platinum wire as counter electrode. The sensor worked in flow injection analysis system (FIA) using a potentiostat (QuadStat 164, eDAQ, USA). The linear measuring range was 0.01-0.5 mM in histamine equivalent (phosphate buffer 100 mM, pH 7.0).

NOVEL BIOSENSOR METHOD FOR DETERMINATION OF BIOGENIC AMINES IN WINE

The developed biosensor method was investigated for the analysis of different wine samples. The biogenic amine content was also measured by HPLC method for validation [2,3].


Catherine Veyrat

Charlotte Sy

Patrick Borel

Olivier Dangles

Stability in the presence of iron and antioxidant activity in a model of the gastro-intestinal tract of reference and bacterial carotenoids

scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

STABILITY IN THE PRESENCE OF IRON AND ANTIOXIDANT ACTIVITY IN A MODEL OF THE GASTRO-INTESTINAL TRACT

OF REFERENCE AND BACTERIAL CAROTENOIDS. The stomach is a bioreactor [1] in which macroand micro-nutrients can interact. Stability of carotenoids in the gastro-intestinal tract could be challenged in the presence of pro-oxidant species like iron, which is present in food and especially in red meat. Moreover, in gastric conditions, dietary lipid peroxidation may be especially fast due to high dioxygen concentrations, acidic pH and constant mixing [START_REF] Lapidot | Lipid peroxidation[END_REF]. Thus in the presence of polyunsaturated fatty acids and iron, lipid peroxidation could produce deleterious oxidized lipids in the stomach. In sufficient concentration in this compartment, carotenoids could exert antioxidant activity to protect polyunsaturated lipids and prevent the formation of compounds deleterious for human health.

We studied the stability of carotenoids in the presence of dietary iron in a mildly acidic (pH 4) micellar solution as a simple model of postprandial gastric conditions [3]. The oxidation was initiated by free iron (Fe II , Fe III ) or by heme iron (metmyoglobin, MbFe III ). Fe II and metmyoglobin were found much more efficient than Fe III at initiating β-carotene oxidation. For β-carotene, UPLC/DAD/MS and GC/MS analyses revealed a complex distribution of β-carotene-derived products including (Z)-isomers, epoxides and cleavage products of different chain lengths. The mechanism and potential nutritional consequences of iron-induced carotenoid oxidation will be discussed.

A model of lipid peroxidation in the gastrointestinal tract was previously set up in the laboratory [4]. We compared the ability of various carotenoids (lycopene, β-carotene, astaxanthin, and mixtures of bacterial carotenoids) to inhibit the iron-induced peroxidation of linoleic acid micelles at two different pH of the stomach during the digestion [5]. Under these conditions, newly identified carotenoids from spore-forming bacteria [6], were found to have greater antioxidant than the reference carotenoids. Results will be discussed

a, b

 b Catherine Caris-Veyrat 1 , a, b, c, d, e Charlotte Sy, c,d,e Patrick Borel, and a,b Olivier Dangles a INRA, UMR408 Safety and Quality of Plant Products, Site Agroparc, F-84000, Avignon, France (e-mail: catherine.caris@avignon.inra.fr); b Université d'Avignon et des Pays de Vaucluse, UMR408 Safety and Quality of Plant Products, F-84000, Avignon, France; c INRA, UMR1260 Nutrition, Obesity and Risk of Thrombosis, F-13385 Marseille, France; d INSERM, UMR U1062, F-13385 Marseille, France; e Aix-Marseille University, Faculté de Médecine, F-13385 Marseille, France.

  taking into account differences in chemical structures which might induce different localization at the lipid/water interphase or inside the micelle. Antioxidant activity of reference carotenoids and bacterial carotenoids from 2 different Bacillus strains (HU36 and GB1) at pH 5.8 and 4. IC50 = inhibitory concentration necessary to reduce oxidation by half. The lower the value, the greater the antioxidant capacity of the carotenoid.

Acknowledgements

This work was supported by a Grant from the European Community's Seventh Framework Program (Colorspore, Small Collaborative Project N° 207948, coordinator: S. Cutting, Royal Holloway, University of London, UK)


Anna Katharine Mansfield

David C Manns

Lauren M Thomas

Coquard Lenerz

Matteo Marangon
email: marangon.matteo@gmail.com

Paul A Smith

Axel Marchal
email: axel.marchal@u-bordeaux2.fr

Pierre Waffo-Teguo

Eric Genin

Jean-Michel Merillon

Denis Dubourdieu

Thomas Salmon

Richard Marchal
email: richard.marchal@univ-reims.fr

Julien Michel

Michael Jourdes

Thomas Giordanengo

Nicolas Mourey

Pierre-Louis Teissedre
email: p.teissedre@u-bordeaux2.fr

Laurent Pechamat

Liming Zeng

Rémy Ghidossi

Yuri Romboli
email: yuri.romboli@unifi.it

Silvia Mangani

Giacomo Buscioni

Massimo Vincenzini

Chloé Roullier-Gall
email: c.roullier.gall@gmail.com

Philippe Schmitt-Kopplin

Régis D Gougeon

Doreen Schober
email: doreen.schober@dlr.rlp.de

Michael Wacker

Hans-Georg Schmarr

Ulrich Fischer

Aurélie Tachon

Thomas Karbowiak

Dominique Champion

Jean-Pierre Bellat
email: jean-pierre.bellat@u-bourgogne.fr

EXTRACTION AND RETENTION OF TANNINS IN RED HYBRID WINE PRODUCTION

Keywords: , phenolic extraction, enological tannins, tannin sorption wine, protein, haze, mechanism Sweetness, oak wood, Quercotriterpenosides, HRMS Proteins, pectins, flocculation, pectinases, proteases, foam Oxygen, Ellagitannins, Red wine, Oak wood, Organoleptic properties, Astringency, Bitterness Oxygenation, Acidity, Red Wine, Pyranoanthocyanins, screw caps, synthetic corks Saccharomyces cerevisiae, Candida zemplinina, bioactive compounds, higher alcohols pinot noir grapes, wine, terroir, vintage, FTICR-MS Aroma, precursors, yeast, sparkling wine cork stopper, compression, water, sorption, visco-elasticity

Red hybrid wines

Securing wine stability is an essential step of the winemaking process. Wine grapes contain proteins that, when not removed during winemaking, can make their way into the bottled wines in a soluble state, in which case the wine is seen as clear. With time, and particularly after exposure to high temperatures, the proteins can slowly denature and subsequently aggregate. As these aggregates become larger they scatter more light and they are seen as haze. Haze from wine contains mainly chitinases, thaumatin-like proteins and non-proteinaceous compounds, and is the result of a complex interplay between a range of proteins and chemical and physical factors. Since hazy wines are not saleable, this instability is generally prevented via bentonite fining, a treatment effective in removing the grape proteins responsible for haze formation, but with drawbacks such as wine volume loss and disposal costs, as well as perceived effects on wine flavor and quality. Hence, alternatives are sought. So far, the search for alternatives to bentonite has not yet resulted in commercially viable solutions able to compete with bentonite's efficacy and low cost. It is believed that a better comprehension of the causes for haze is needed, because a thorough understanding of the mechanisms of protein haze formation has the potential to lead to the development of novel, efficient, and environmentally sustainable winemaking processes to prevent haze from forming. Here we present an overview of the recent advances on the study of protein instability of white wines, with particular attention to those obtained by our group. This will include: i) notions on the role of purified wine proteins, ii) explanation of the role of some non-proteinaceous wine components, iii) notions on the effect of different unfolding temperatures and unfolding/aggregation behaviour of grape proteins. A revisited mechanism of haze formation accounting for the several recent breakthroughs in the field will be presented.

The research of key-compounds involved in wine aromas and tastes constitutes a major field of investigation in enology. Although sweetness is a subtle but crucial feature of dry wines quality, its molecular origin has been poorly studied. This lack of knowledge might partly originate from the high chemical complexity of wine. Therefore, the study of tasteactive compounds appears as a great challenge for the understanding of wine flavors and requires the implementation of efficient and sensitive analytical techniques. Within this context, High Resolution Mass Spectrometry (HRMS) has recently seen impressive developments based on a metabolomic-inspired approach [1,2].

The present study reports a complementary use of Orbitrap-HRMS aimed at identifying isomers and derivatives of the triterpenic molecules Quercotriterpenoids (QTT) I and II recently discovered in oak wood and established as sweeteners [3]. An oak extract was screened by high accuracy molecular mass measurement in order to research targeted empirical formulas corresponding to putative structural analogues to QTT I and II. These researched compounds were observed in our extracts. So far, these derivatives of QTT have never been identified in nature. Their purification was performed by combination of centrifugal partition chromatography and high performance liquid chromatography guided both by HRMS. Thereafter, their structures were confirmed by NMR and their sensory properties assessed.

This study highlights the first identification of several triterpenoic compounds, some of them exhibiting sweet properties, and improves our chemical knowledge of oak wood and wine composition. Furthermore the approach described in this work arises as a promising methodology to discover new taste-active compounds. within a grape variety. Sensory analysis also proved that yeasts species alter the attribute intensities of wine within a single grape variety. Proteins secreted by yeasts during and shortly after alcoholic fermentation contribute to wine composition. The impact of extracellular enzymes in particular has been largely documented but the entire proteome has also been shown to relate the history of the process that led to the generation of a specific wine. The contribution of non-Saccharomyces yeasts towards some aspects of wine quality has been explored but although their ability to secrete enzymes of oenological interest has been reported, little is known about their global contribution to the wine proteome and if proteins can be regarded as markers of interactions with Saccharomyces sp., especially in the context of co-inoculation.

In this study, the proteins of different non-Saccharomyces yeasts released under fermentative conditions either on their own or co-inoculated with S. cerevisiae were identified. The results revealed that the number of proteins varies greatly between species. In mixed culture fermentation, proteins from both Saccharomyces cerevisiae and the non-Saccharomyces yeasts present were identified but although cell wall proteins could expectedly be identified in all wines, others were either only present in some of the wines or completely absent.

Proteins of obvious oenological interest identified in this study include various βglucosidases, endochitinase and invertase. All of these have been reported in literature to have potential implications on wine quality. The identity of several proteins also suggests that specific interactions occurred between S. cerevisiae and the non-Saccharomyces yeasts. The nature of these interactions was dependent on the non-Saccharomyces species.

The untargeted approach used in this study to characterize proteins released by yeasts during wine fermentation broadened our knowledge and understanding of selected non-Saccharomyces yeasts, their interactions with S. cerevisiae and their potential impact on wine properties.

STATISTICAL ANALISYS OF METAL CONTENT OF WINES OF HUNGARY

Zoltán MURÁNYI a , Csaba CSUTORÁS a , Attila KISS a a Eszterházy Károly College, , Food Science Institute, EGERFOOD Knowledge Centre, Eger, Hungary E-mail: mzperx@ektf.hu; Phone: 36-36-520-400/4134; Fax: 36-36-523-464 Key words: Tokaj-wines trace elements statistical methods On the basis of the experience gained during the course of the recent years within the European Union and in Hungary as a part of it, in order to strenghten the reliability of the protection of origin of wine currently operating, it is obviously expected by the customers that the results achieved via analytical identification be announced.

Wine is considered as a highly complex balance system involving thousands of components which is objected to constant alteration until the moment of its consumption. Its quality seems to be influenced by four factors, or rather group of factors.

The physical and chemical compositions of growing areas appears to have an exceptionally crucial significance in the formation of the wine's features. Beyond the production of these sorts of wines, not only organoleptic but also analytical identification has a great importance. Browsing through technical literature one may provide the readers with several references to the applicability of various methods investigation or certain compounds for the identification of origin, a system capable of solving the problem with the necessary level of reliability at a reasonable price, on the other hand, has not been discovered yet.

One of the potential solutions is the determination of the fingerprint of wine samples.

Our experiments have been conducted in the case of Tokaj-wines produced in different fields, processed in the similar ways. The results of the wines' organoleptic qualification and those of main and trace element analysis have been evaluated by the application of statistical methods. Brettanomyces bruxellensis and the consequences of its development in wines are a continuous threat for wine quality. This undesirable yeast is able to develop during aging under difficult conditions. It is also responsible for the production of negative aromatic compounds such as volatile phenols related to sensory descriptors such as animal-like, horse, barnyard, band aid and medicinal. Nowadays at an international scale, volumes concerned by this defect become significant. Several strategies are useful in order to control Brettanomyces and its development in musts and wines. However these strategies are not always sufficient. In this context, chitosan of fungal origin has been introduced as a new potential interesting tool to control Brettanomyces in the context of winemaking [1]. Recent studies have showed the impact of a fungal origin chitosan application on wines contaminated with Brettanomyces, leading to the elimination of Brettanomyces cells, even at high levels of populations up to 10 5 -10 6 CFU/mL and at the dosage of 4 g/hL [2]. In these studies, the chitosan preparation was added and the wine racked off after 10 days and the efficiency of the treatment was evaluated in a short delay after the treatment. Due to the necessity to control wine microbiological stability during the period of aging, especially in the context of red wine aging in barrels, our research focuses on the application of an enological chitosan preparation in order to prevent wine from Brettanomyces contamination along the aging period at both pilot winery-and at winery-scale. This communication presents the evaluation of the impact of different addition protocols of an enological chitosan preparation on Brettanomyces population evolution and volatile phenols content along the aging, up to 9 months. To conclude, the results confirm the interest of chitosan as a preventive tool to control Brettanomyces in the context of wine aging.

EVALUATION OF THE IMPACT OF A FUNGAL ORIGIN CHITOSAN PREPARATION ON BRETTANOMYCES IN THE CONTEXT OF WINE AGING

Microoxygenation is a widespread technique in winemaking. Indeed, it is known that oxygen can impact wine positively by decreasing herbal and reductive notes, as well as induce colour stabilization [1]. Chemically, the dissolved oxygen is able to produce ethanal by oxidizing the ethanol. Then, this ethanal can make ethyl bridges between flavonoids such as tannins and anthocyanins which can lead to huge polymeric structures [2]. The ethanal is also responsible for generating new pigments, called pyranoanthocyanins (vitisin B). These compounds result of a cycloaddition reaction between a vinyl group and the 5-OH group and C-4 of the anthocyanin followed by an oxidation step leading to the aromatization of pyranic ring D [3]. The aim of this work was to determine the impact of both oxygen and pH levels on the chemical composition and organoleptic properties on a young Merlot wine during 4 months.

The red wine pH was adjusted at 3, 3.5 and 4 with sulphuric acid and sodium hydroxide. For each pH, four quantities of pure oxygen were studied : 0, 2, 8 and 20 mg/L. Each week, oxygen was added according to wine consumption in order to keep the chosen amounts at the same levels.

First, global chemical impacts of both oxygen and pH were studied over a period of four months. Samples were analyzed each month in order to perform chemical follow-up of the wine. Free anthocyanins amounts showed a decrease related to oxygen as well as acidity. The same impact was observed on the evolution of free and total SO 2 . Colorimetric analyses showed an increase in color intensity according to oxygen amounts. However, the trend of evolution was clearer at acidic pH.

Secondly, after the period of four months, a pyranomalvidin-3-O-glucosideprocyanidin dimer was quantified in all the modalities. The results showed that, for the same pH, its quantity was correlated with oxygen concentrations. Moreover, for the same quantity of oxygen, the concentration of this pigment was related to acidity. The physical chemistry of sparkling beverages, such as champagne, is a field of research that has been well advanced experimentally in recent years [1]. Indeed, several phenomena, such as diffusion, have been extensively studied [2]. Accompanying theoretical investigations which could further elucidate the experimental findings, are nevertheless rare, and hence the role of each type of molecule in the diffusion process remains unclear although diffusion is considered the main physical process responsible for the nucleation and growth of carbon dioxide bubbles in sparkling beverages.

APPROACHING CARBON DIOXIDE DIFFUSION IN CHAMPAGNE WINES THROUGH MOLECULAR DYNAMICS

In the present work we report a theoretical study of the CO 2 diffusion coefficient in a liquid, with a composition close to that of champagne. We have performed molecular dynamics simulations (integrating Newton's equations of motion) of CO 2 molecules in water and in a water/ethanol mixture respecting Champagne wine proportions. It is shown that, for champagne, generalized Fick's law for the determination of multicomponent diffusion coefficients can be approximated by standard Fick's law valid for binary systems. Diffusion coefficients computed from the Stokes-Einstein formula are in very good agreement with theoretical and experimental data from the literature. The addition of ethanol to a CO 2 /water mixture is found to be the main factor responsible for the value of the CO 2 diffusion coefficient in champagne, despite the fact that these sparkling beverages are multicomponent drinks. This implies that the CO 2 diffusion coefficient in Champagne wines should not depart significantly from a value of about 1.5-1.6×10 -9 m 2 /s, at 20°C, since the percentage of alcohol is restricted to within a narrow range of 12-12.5 % v/v in this emblematic hydro-alcoholic sparkling beverage. Molecular dynamics simulations were also performed in a wide range of champagne temperature, namely from 4 °C to 20 °C. As expected, the diffusion coefficient of CO 2 was found to increase with increasing temperature.

Le Big Data dans sa dimension informatique peut être la source d'une modification des relations entre vendeurs et acheteurs grâce à l'interprétation qu'il permet des connaissances et des émotions de l'individu, de création de valeur dans le E-commerce (avec en particulier une modification potentielle des conditions de formation des prix). De plus, le contrôle et l'extraction des informations par les vendeurs modifient le degré de concurrence entre ceux-ci car si rapidement Internet a révolutionné le marketing en le dotant de nouveaux outils et en enrichissant la connaissance client, jamais les entreprises n'ont disposé d'autant de données sur leur environnement. Elles sont aujourd'hui face à un énorme défi pour les exploiter.

Le rapide développement du Big Data devient une problématique centrale au sein des organisations, et en particulier au sein des directions marketing, des services "commercial" et "client". En effet, le Big Data suit à la trace le consommateur dans sa vie quotidienne notamment au travers de son surf sur Internet. Les données traitées automatiquement accouchent d'informations inédites, issues du croisement de données hétérogènes (géolocalisation, abonnement, niveau de revenu, etc.).

La question de la transparence de l'information est aussi importante : si le E-commerce voit les coûts de recherche d'information diminués (particulièrement avec les sites comparateurs ce qui incite à la diminution des prix), en revanche des effets pervers de la transparence apparaissent en raison de la forte hétérogénéité des prix. Ainsi les commerçants obtenant par le web des informations détaillées sur le consommateur, ceux-ci peuvent plus facilement personnaliser l'offre et donc ensuite accroitre la dispersion des offres et des prix. D'où : l'accentuation des phénomènes de discrimination des prix (avec auto-sélection2 ) avec élaboration d'une tarification hétérogène.

Le monde du vin n'est donc pas à l'écart de ce bouleversement en cours des relations marchandes et sociétales. Notre article visera à repérer dans la pratique, comment s'illustre ou va s'illustrer ce Big Data dans le monde du vin ?

-Certes la révolution en cours de la relation client est le plus souvent évoquée : par exemple, la prise en compte directe des préférences du consommateur en matière de vins et son impact sur ses achats de vin (d'où déjà : la multiplication des sites sensés faciliter le choix d'un vin et/ou l'alliance vins/nourriture) -Mais il ne faut pas non plus ignorer l'impact sur la concurrence entre les négociants et leur stratégie des prix grâce à la mise en place de logiciels de prévisions de récolte. -Les effets dévastateurs sur la réputation d'un vin de certaines informations déposées sur les réseaux sociaux comme la rapide modification des conditions de cotation des vins les plus prestigieux, voire le Big Data au service de l'élasticité des prix sont sans doute encore sousestimés. -La potentialité accrue de suivis des conditions climatiques dans les vignes ne doit pas être réservé à quelques producteurs, etc.

PREDICTION OF THE EFFECTS OF ENVIRONMENTAL FACTORS ON THE SYNTHESIS OF FERMENTATIVE AROMAS

Stephanie Most volatile compounds of organoleptic interest for young and white wines are synthesized by yeast metabolism. Their production depends both on yeast strain and on fermentation conditions. The objective of this work was to study the combined effects of temperature, initial assimilable nitrogen and lipid contents on the production of fermentative aromas. Fermentations were performed using Lalvin EC1118 ® strain and thirty compounds (higher alcohols, acids, ethyl and acetate esters) were measured by GC-MS.

To identify the most discriminating factors in the production of each flavor compound and possible interactions between those factors, experiments were carried out according to a Box-Behnken matrix. This experimental design limits the number of experiments while allowing the calculation of the response surface for each studied parameter and therefore estimating the conditions leading to a maximum (or minimum) production of volatile compounds.

In addition, the "weight" of each environmental factor was calculated. We found that nitrogen had the greatest impact on a large number of flavor compounds, but the synthesis of several compounds (isobutanol, ethyl esters) was also highly influenced by the lipid content and temperature. To better assess the impact of strain genetic background and to evaluate the genericity of the results, we compared the aroma production of several other yeast strains under the two extreme conditions predicted by the model (330 mg/L of assimilable nitrogen, 2 mg/L of phytosterols at 20°C and 70 mg/L of assimilable nitrogen, 8 mg/L of phytosterols to 28°C) and leading to the highest and lowest production of esters, respectively.

Tyrosol, hydroxytyrosol and tryptophol, three higher alcohols produced by yeast during alcoholic fermentation, are reported to possess several health-enhancing activities, deriving from their free radical scavenging, anticarcinogenic, cardioprotective and antimicrobial properties [1; 2]. Some Authors reported that the final contents of tyrosol, tryptophol and hydroxytyrosol in wine could be influenced by the microbial ecology of the alcoholic fermentation [3]. However, also aeration of musts during alcoholic fermentation could influence the production of higher alcohols in wines [4]. In the present work, the concentration of the three bioactive molecules were determined in wines obtained under laboratory conditions by varying both yeast species (Saccharomyces cerevisiae alone or sequential inoculum of Candida zemplinina and S. cerevisiae) and aeration conditions of grape must during fermentation. Since several Authors, in literature, discussed about fermentative activity and production of higher alcohols by wine yeasts [5], the first part of the study was aimed to describe the kinetics of the experimental fermentations. The values of two kinetic parameters, fermentative vigor (FV48h) and maximum fermentation rate (Vmax), demonstrate that the presence of C. zemplinina had a negative effect on fermentation kinetics in both aerated and nonaerated conditions. Moreover, aeration improves significantly the values of FV48h and Vmax.

In the experimental wines, the highest concentrations of tyrosol, hydroxytyrosol and tryptophol were found when grape musts were fermented by S. cerevisiae alone, under non-aerated conditions. Two-way ANOVA demonstrated that the type of inoculum and aeration affected significantly tyrosol and hydroxytyrosol concentrations in wine, whereas the type of inoculum resulted the sole variable affecting tryptophol concentration In conclusion, the concentrations of tyrosol, hydroxytyrosol and tryptophol in wine depend markedly on yeast species and to a lower extent on aeration conditions of must during alcoholic fermentation. Indeed, the dominance of C. zemplinina in the first stage of alcoholic fermentation strongly affects the contents of all the bioactive molecules here taken into consideration.

The flavour of wine and sparkling wine is significantly influenced by glycosidically bound aromaprecursors in grapes, must and base wines Quantitative analysis of glycosylated aromaprecursors allows an evaluation of the aroma potential of a given must or base wine. Furthermore, yeast strains can be assessed regarding their liberation of aromaprecursors.

Glycosylated precursors from juice and wine samples are obtained and concentrated by an automated solid phase extraction (SPE) system. An aliquot was analysed by FT-MIR, while the other underwent enzymatic cleavage. The extracted free aroma compounds were analysed by gaschromatography/mass spectrometry (GC/MS). Application of a large-volume injection allowed the detection of trace amounts without any further concentration step. Overall 40 substances were quantified using stable isotope dilution assay (SIDA) and combined in the following categories: monoterpenes, C 6 -alcohols, benzene derivatives, C 13 -norisoprenoids and volatile phenols.

Extraction and liberation of aroma compounds from glycosylated precursors were monitored during skin maceration of Riesling and Muscat grapes and varying press regimes. Chemical and sensory analysis of Riesling, Muscat and Chardonnay wines fermented by different yeast strains revealed a significant impact on their composition. Even during secondary fermentation, significant changes were observed in sparkling wines due to the application of various yeast strains.

The use of cork as sealing for wine bottles is due to its low permeability to liquids and gases, imputrescibility and good mechanical properties, in particular its remarkable elasticity [1]. We focused in this study on the compression properties of cork along the radial or the tangential direction at 298 K when cork is stored under various relative humidity environments, from 0 to 100 %.

All stress-strain curves were characterized by an elastic region up to approximately 5 % strain, followed by a large plateau up to 60 % strain caused by the progressive buckling of cell walls.

Firstly, it is worthy to note that the direction of compression significantly affects the Young modulus, with a higher value in radial compression, as already reported by Anjos and Pereira [2,3]. This corresponds to the orientation of the lenticels, which reinforces the rigidity of the material when the strain is applied along their growth direction.

More surprising is the effect of water sorption in cork on its mechanical properties. Both radial and tangential direction exhibit the same behavior, characterized by an increase in the Young modulus up to around 50 % relative humidity and followed by a decrease in rigidity. Maximum observed values are 46.9±8.1 MPa and 22.1±2.0 MPa for radial and tangential directions, respectively. Below that point, the increase in water content leads an antiplasticizing effect while above it gives a more classical plasticizing effect. This is in favor of the existence of an amorphous fraction in cork which goes across the glass transition in this relative humidity range.

  ROLLERO a,b,c,d , Jean-Roch MOURET a,b,c , Isabelle SANCHEZ a,b,c , Anne ORTIZ-JULIEN d , Jean-Marie SABLAYROLLES a,b,c and Sylvie DEQUIN a,b,ca : INRA, UMR1083 Sciences pour l'oenologie, Montpellier, France b : SupAgro, UMR1083 Sciences pour l'oenologie, Montpellier, France c : Université Montpellier I, UMR1083 Sciences pour l'oenologie, Montpellier, France d : Lallemand SAS, Blagnac, France Corresponding author: Stephanie Rollero, rollero@supagro.inra.fr UMR Sciences pour l'oenologie 2 place Viala 34060 Montpellier Cedex 02 France Tel: +33 (0)4 99 61 22 74 Fax: +33 (0)4 99 61 28 57 Keywords: Saccharomyces cerevisiae; fermentative aromas; Box-Behnken design; environmental factors

[ 1 ]

 1 . These odorless precursors are liberated by enzymatic activities of yeast during alcoholic fermentation [2] which triggers the formation of the varietal bouquet during the first or second fermentation [3].

Tiziana Nardi a , Paola Vagnoli a , Andrea Minacci b , Sandrine Gauthier c , Nathalie Sieczkowski d

	tel +39 045 512 555, fax +39 045 519 419
	b ISVEA, Poggibonsi (SI), Italy
	c Kitozyme, Herstal, Belgium
	d Lallemand SAS, Blagnac, France
	E-mail : tnardi@lallemand.com
	Keywords : Brettanomyces, chitosan, aging

a Lallemand Italia, Castel d'Azzano (VR), Italy -via Rossini 14/B,

Discrimination par auto-sélection = basée sur les informations obtenues sur les préférences des acheteurs => l'entreprise propose des prix différents associés à des conditions différentes ce qui conduit à s'auto-sélectionner.

OENOLOGICAL ASPECTS OF SANGIOVESE GRAPES VINIFIED WITH OTHER NATIVE VARIETIES

Sergio PUCCIONI , Alessandra ZOMBARDO, Franco GIANNETTI, Paolo STORCHI Consiglio per la Ricerca e la Sperimentazione in Agricoltura -Unità di Ricerca per la Viticoltura, Via Romea 53, 52100 Arezzo, Italy. Tel: +39-0575-987081 -Fax: +39-0575-987069. E.mail: sergio.puccioni@entecra.it Key words: : Cofermentation, wine colour, native vines.

It was a Tuscan winemaking tradition to mix Sangiovese with other varieties. It's still the opinion of some producers that this practice allows to soften the harshness of Sangiovese and it makes the wine more harmonious. The white grape musts have a low polyphenol content, mainly represented by hydroxicinnamiltartaric acids. With the maceration, however, it's possible to obtain musts/wines rich in procyanidins and flavans. These molecules have the ability to react with the anthocyanins, forming coloured polymers more stable and less susceptible to oxidation and to discolouration [1][2]. In this study, two wines (vintage 2012), obtained from a Sangiovese blend (85% w/w), respectively with Colorino and Malvasia, were compared with a pure Sangiovese wine. The analysis, in addition to general parameters, have focused on the evaluation of the phenolic profiles and the colour compositions [3,4]. The results obtained in this study indicate that the addition of Malvasia bianca lunga to Sangiovese in vinification resulted in a decrease of the concentration of anthocyanins. The colour intensity, however, is not affected significantly, in this case, by the addition of white grapes in the winemaking process. The use of Colorino, instead, integrated the anthocyanic concentration, with consequent improvement in the chromatic parameters.

Metabolomics characterization of the chemical evolution of bottled wines

Chloé Roullier-Gall a,b , Michael Witting b , Régis D. In the present study, combined non-targeted metabolomics approaches were used for the analysis of a vertical series of Burgundy wines, representing natural bottle evolution in cellars. The purpose of this study was to characterize in a non-targeted way the evolution of the chemical diversity of white wines after bottling. FTICR-MS analyses led to a matrix composed of more than 10 000 distinct masses for the different wines from the vertical series. Each of these wines exhibited numerous similarities with all other wines in the vertical, but also specific masses to each vintage. Differences between wines increased during the bottling period, or aging. Specific masses that influenced most this differentiation were extracted, identifed and structurally characterized by UPLC-MS and UPLC-MS 2 .

DIFFUSION OF OXYGEN IN CORK: KNUDSEN OR FICK REGIME?

Aurélie TACHON a,b,c , Thomas KARBOWIAK a , Jean-Marc SIMON c , Régis GOUGEON Key words: diffusion, permeation, cork stopper, oxygen transport During post bottling aging, oxygen transfer occurs through the stopper and can lead to oxidation reactions. Studying diffusion of oxygen through the cork is of a relevant interest. At present, there is still a misunderstanding in the transport mechanism. Some authors claim that oxygen transport follows Knudsen law [1], while others say that diffusion is governed by Fick law [2]. Moreover the limiting step of oxygen transfer is not clearly identified: is it the diffusion through the cells, the cell walls, the lenticels, the plasmodesms…? The aim of this work is to clearly identify which law governs the oxygen transfer and what is the limiting step.

Oxygen transfer through cork wafers was measured using a manometric permeation technique. The experimental device and the procedure used have been described in detail [2]. In the present work, permeation of oxygen was studied at 298 K on 3 mm cork wafers and for various initial pressures of oxygen (50 < p < 800 hPa).

Results show that the diffusion coefficient of oxygen decreases as the initial pressure increases. This means that oxygen transport through cork does not follow Knudsen regime because the Knudsen diffusion coefficient is independent on the pressure. On the contrary, the dependence of the pressure on the diffusion coefficient is well taken into account by the Fick law considering mass transfer as an activated process. Analysis of data shows that the limiting step in the transfer of oxygen is the Fick diffusion in the cell walls and that the oxygen molecules go through a gas phase in large spaces which could be lenticels or more probably the inside of empty cells when moving from one site to another.

HOW METABOLITE PRODUCTION CAN BE MODULATED IN WINE BY AN INTERACTION BETWEEN TWO YEASTS? EXAMPLE OF ACETATE PRODUCTION BY SACCHAROMYCES CEREVISIAE CO-CULTURED WITH METSCHNIKOWIA PULCHERRIMA

Mohand SADOUDI, Sandrine ROUSSEAUX, Hervé ALEXANDRE, Raphaëlle TOURDOT-MARECHAL UMRA 02 102 PAM Université de Bourgogne /AgroSup Dijon EquipeVALMIS, IUVV -Institut Jules Guyot -21078 Dijon cedex, France E-mail :tourdot@u-bourgogne.fr Key words: yeasts interaction, non-Saccharomyces yeast, acetate production Previous studies reported that the use of non-Saccharomyces yeasts in mixed culture with S. cerevisiae in wine fermentation leads to reduce volatile acidity contents, however, their impact on the metabolic pathway involved in acetic acid formation in S. cerevisiae have never been investigated. In this context, we compared the acetic acid production kinetics of S. cerevisiae pure culture and S. cerevisiae/Metschnikowia pulcherrima mixed culture during alcoholic fermentation, in parallel with the study of the expression of six genes involved in acetic acid metabolic pathway using a reverse transcription-quantitative PCR (RT-qPCR) method with relative quantification. The results showed that interaction occurred between the two yeasts reducing acetic acid amount. The mixed S. cerevisiae/M. pulcherrima culture at 1:10 ratio produced 37% less acetic acid than S. cerevisiae pure culture. At transcriptomic level, we observed, despite the complexity to correlate gene expression levels to the acetic acid kinetic formation, that the expression levels of these genes were significantly affected. We show for the first time that the entire acetic acid metablic pathway in S. cerevisiae can be altered by the presence of a non-Saccharomyces yeast.

THE INFLUENCE OF WILD YEASTS BIODIVERSITY AND GRAPE PROCESSING ON AROMA COMPOUNDS IN WINES OF THE GRAPE VARIETIES "RIESLING" AND "SPÄTBURGUNDER"

Daniel GERHARDS, Caroline LEHNIGK and Christian VON WALLBRUNN Hochschule Geisenheim University, Institute for Microbiology and Biochemistry, Von-Lade-Str.1, 65366

Geisenheim, Germany, phone: 0049-6722-502331, fax: 0049-6722-502330

Email: christian.wallbrunn@hs-gm.de Keywords: biodiversity of yeasts, yeast identification by FTIR spectroscopy, grape processing, aroma compounds About the influence of different enological grape processing methods on the biodiversity of yeasts in spontaneous fermentations and later on in the resulting wines only less data are available. The aim of this project sponsored by the AiF/FEI was to investigate the influence of several grape processing methods like different maceration times, mash heating, mash fermentation on yeast populations and later on the spontaneous fermentations. How are the aroma compounds and the taste of resulting "Riesling" and "Spätburgunder" wines influenced?

To check the influence on yeast populations and resulting aroma compounds by the processing of white grapes, grounded "Riesling" grapes would be compared to approaches with different maceration times of mash of the same variety. Effects on yeast populations and aromas would be analyzed using the processing methods of mash heating, mash fermentation and the combination of cold maceration followed by mash fermentation for "Spätburgunder" as a red grape variety. Sample material was taken at different time points of the processing, the fermentation and the resulting wines to analyze yeast populations and typical compounds. For each sampling point 100 randomly isolated yeasts were identified by FTIR spectroscopy. Chemical analyzes of the different aroma compounds were done by FTIR, HPLC, enzymatic measurements, and GCMS. All produced wines were tasted and sensorial described by a tasting panel. All collected data are the basis to correlate the different grape processings to the occurring yeast populations and the aromas of the spontaneous fermented wines. With the knowledge of the processes of the several steps of grape, mash and must processing, also the spontaneous fermentations and the possibility to control these steps, it would be an important precondition for the wine industry to make the risks of spontaneous fermentations more calculable and controllable.


Mathieu Buoro

Julien Papaix

Cyril Piou

Etienne Prévost

Investigating the demogenetic responses of exploited Atlantic salmon (Salmo salar) populations to climate change

Keywords: climate change, fisheries, induced evolution, individual, based model, life, history strategies, Salmo salar

à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

Abstract

A key aim of current ecological research is to predict whether and how populations will be able to respond to environmental change. However, our predictive ability is still limited by the complexity of environments, organisms life cycle and especially by the challenges of teasing apart evolutionary change from more 'plastic' responses to environmental perturbation. Simulation studies provide a powerful tool for disentangling eco-evolutionary processes and investigating interactive, synergistic effects among multiple factors in order to fully understand the resilience of populations in the face of various scenarios of climate change. Using, an Individual-based model, we investigate the demogenetic consequences of environmental change scenarios on an exploited population of Atlantic salmon Salmo salar. Our results show that increasing flow amplitude and water temperature in freshwater, and poor oceanic growth conditions resulting from environmental change drove mainly demographic consequences and phenotypic responses, such as a shift towards a multiple-sea-winter life history accompanied by a decline in population size. Effects of environmental change was also contrasted with fisheries strategies impacts to investigate whether fisheries induced evolution and how selective fisheries can promote adaptation to climate change. We show that increased selective fishing against multiple-sea-winter fish mainly induced an evolutionary effect in the form of a lower maturation threshold in females, increasing the proportion of one sea-winter fish. The maturation threshold of males was not modified by selective fishing due to their earlier reproduction and return after a single winter at sea, thereby avoiding most of the selective effects of fishing.

  Investigating the demogenetic responses of exploited Atlantic salmon (Salmo salar) populations to climate change Mathieu Buoro * 1 , Julien Papaïx 2 , Cyril Piou 3 , and Etienne Prévost 4 1 UMR INRA/UPPA Ecobiop -Institut national de la recherche agronomique (INRA) : UMR1224 -France 2 Biostatistique et Processus Spatiaux (BIOSP) -Institut national de la recherche agronomique (INRA) : UR546 -Site Agroparc Domaine St Paul 84914 Avignon cedex 9, France 3 CIRAD UMR CBGP -CIRAD -France 4 UMR INRA/UPPA Ecobiop -Institut national de la recherche agronomique (INRA) : UMR1224, Université de Pau et des Pays de l'Adour -UPPA (FRANCE) -Aquapôle, Ibarron 64310 Saint-Pée sur Nivelle, France, France