Wine Conservation Research Articles

A key to wine conservation lies in the glass-cork interface.

This study investigates the evolution of the oxygen barrier properties of the bottleneck-stopper system under conditions simulating the conservation of wine in the bottle (presence of model wine, storage position, and temperature) over a long aging period of 24 months. The results highlighted that the oxygen diffusion coefficient of the stopper alone is not modified regardless of the storage conditions. At 20°C, the presence of model wine favors oxygen transfer at the glass-cork interface, accounting for nearly 75% of total oxygen transfer in comparison to cork studied without model wine. Yet, the position of the bottle during storage, vertical (i.e. cork in contact with the vapor phase of the model wine) or horizontal (i.e. cork in contact with the liquid phase), does not influence the oxygen transfer. At higher storage temperatures (35 and 50°C), the barrier properties of the bottleneck-cork system remain stable up to 9 and 3 months, respectively. After this period, an alteration of the barrier properties is observed with an increase of the transfer at the glass-cork interface.

Validation of a new method for the rapid determination of free sulfur dioxide in wine

Sulfur dioxide is widely used in most wines around the world. The determination of free SO2 is probably the most frequently conducted analysis in the wine industry used to assure wine conservation. The most frequently used methods of analysis are the aeration-oxidation method and the Ripper method. Both methods are relatively long and require specialized technicians. A new methodology based on voltammetry has been developed. It is based on a specialized hand-held automatic and fast analyzer that uses analytical stripes. This study compared this new method with the traditional aeration-oxidation and Ripper methods in a wide range of red and white wines. The results showed a good correlation of the voltametric method with the aeration-oxidation method as a standard and very similar results were observed with the Ripper method. Variability and precision were also high, validating the use of the proposed method for daily use in cellar work.

Microventilation system improves the ageing conditions in existent wine cellars

Background and Aims The importance of indoor environmental conditions in a cellar is well known and continuously investigated. The process of wine ageing consists of several steps, during which temperature (T) and relative humidity (RH) play a fundamental role as the quality of the final product is strongly related to stable and suitable environmental conditions. Critical factors, such as mould growth or wine evaporation, have emerged when ventilation has proved to be insufficient or poorly designed. The limitation of stagnant areas and the homogeneity inT and RH provide for proper wine conservation; however, unwanted local conditions can occur in the zones with insufficient air exchange. Methods and Results Considering these aspects, a controlled microventilation and monitoring system was installed in a case study cellar, and T and RH were monitored for 1 year. The data have been analysed to investigate criticalities of the environmental conditions. The ventilation was activated in specific critical conditions to increase the homogeneity of the T and RH in the critical zones. The results show that the microventilation system improves the homogeneity of both T and RH without affecting the average values. Conclusions The study demonstrated the efficacy of the system and indicated possible modifications to improve system performance. Significance of the Study The system proved to be a useful tool for both improving the environmental conditions and providing useful information to the winemakers about the ageing conditions.

Energetic Retrofit Strategies for Traditional Sicilian Wine Cellars: A Case Study

Sicily is characterized by rural buildings, Palmenti, destined to wine production, which are scattered along the countryside and part of the local historical heritage. There are different types of rural buildings, but all have in common the use of ancient and well-established bioclimatic techniques for wine conservation and aging. Most of them were built with the double function of living space for the owner and productive spaces for all the activities correlated to the cultivations. Indeed, many rural houses, destined to the wine production, are characterized by wineries and wine cellars (the first for the wine production, the second to store the wine for the aging process). The growing production of high-quality Sicilian wines, very appreciated all over the world, leads to upgrade the ancient Palmenti to seek optimal hygrothermal conditions and, therefore, to guarantee high performance of the produced and stored wines. The purpose of this study is to investigate how the retrofit measures taken to comply with the energy regulations could affect the thermal behavior of a wine cellar constructed with consolidated bioclimatic technics. The results show the importance of not insulating the solid ground floor for maintaining suitable temperatures for the fermentation and aging of wine. This study can be useful for future analysis when comparing the optimal hygrothermal conditions of wine cellars located in homogeneous viticultural areas (with same climate, geology, soil, physical features, and height) in other parts of the world.

Wine-on-tap: A study on the conservation of wines in keg Ecofass®

As more and more consumers around the world integrate the choice of healthier, more ethical and eco-friendlier food and beverages in their lifestyle, the wine industry is pushed to develop more sustainable production, distribution and consumption solutions. In search of wine preservation improvements that would have both economic and ecological positive impacts, the wine industry has been investing resources in research, development and innovation regarding alternative packaging and distribution solutions for years. The keg Ecofass®is made of recyclable plastic material, high density polyethylene (HDPE) in which there is an aluminium pouch containing the liquid food. It was a question of knowing if this type of container was adapted to the conservation of the wines during several months. The method of storage and distribution has also been studied to know the impact on the oenological and sensory quality of the wines. Likewise, the nature of the pressure gas (nitrogen or compressed air) has also been tested. The contents of free and total SO2and CO2were monitored, and sensory analysis tests were carried out. Nevertheless, at the sensory level, the judges were able to note significant differences between the wines.

Bioprotection as a tool to free additives winemaking: Effect on sensorial, anthocyanic and aromatic profile of young red wines

The traditional methodology to make red wine combines the use of Saccharomyces cerevisiae yeast and lactic acid bacteria together with sulphur dioxide (SO2), to ensure wine conservation, preventing oxidation and producing microbiological stable wines. The purpose was to study a recent red winemaking biotechnology, through the use of bioprotectors microorganisms (Lactobacillus plantarum and Lachancea thermotolerans), allowing both fermentations (alcoholic and malolactic) taking place at the same time and without the addition of preservatives as SO2. This new winemaking strategy has been reported to be efficient since it has the advantage to produce wines with no SO2, with higher titratable acidity and esters than control wines which followed a conventional fermentation technique. The anthocyanin composition was barely modified by the bioprotectors use and from the sensorial point of view wines were better evaluated, with more fruity, compote, pepper and lactic aromas and more fresh, acid, bitter and astringent than control wines.

Orthogonal optimization of extraction and analysis for red wine residues in simulated and archaeological materials using LC/MS and HPLC methods

Identification of red wine residues in archaeological potteries can yield good insight into the development of red wine culture and the history of winemaking. In this work, the ultra- sonication extraction method was developed to extract the organic acids in simulated red wine residues, while the optimization of extraction condition was studied through orthogonal methods. Moreover, the availability of the proposed research method in archaeological research was also investigated by extracting and analyzing two real archaeological samples. The results obtained from the liquid chromatography/mass spectrometry (LC/MS) proved that the tartaric acid can be acted as the biomarker of red wine. The range analysis of orthogonal methods indicated that the temperature is the main factor on the extraction efficiency of tartaric acid, followed by the proportion of methanol in the solvent, and finally is the extraction time. More importantly, tartaric acid can be identified in the real archaeological sample using the proposed extraction and analysis method, indicating its high verifiability and reliability. This work would provide a complete set of analysis method to identify the traces of wine organic residues in archaeological samples, thus understanding the production and conservation of wine or even tracking back to the start brewing process of wine.

Retrofit interventions in non-conditioned rooms: calibration of an assessment method on a farm winery

In the Mediterranean area, most wine farms make use of unconditioned above-ground buildings for wine conservation and ageing. Those buildings are usually constructed without a specific temperature control design, therefore indoor temperature distributions and trends can be suboptimal for wine storage. At the same time, various elements (commonly available in farms such as straw bales and climbing plants) could be used to create cheap constructive solutions capable of improving building's thermal behaviour. This study aims to test the effectiveness of different retrofit interventions for thermal behaviour improvement in unconditioned above-ground farm buildings, referring to wine-ageing requirements. The alternative design solutions are evaluated through energy simulations, calibrated and validated on an Italian case study. The results show the importance of roof insulation, and the improved performance of the combination of more retrofit strategies. The proposed approach can be extended to other passive strategies and proves useful to provide information to optimize, or even avoid, conditioning systems.

Incidence des conditions de conservation des vins blancs sur leur teneur en composés soufrés volatils

Dans ce travail, nous avons etudie l’incidence de quelques parametres de conservation des vins issus des cepages blancs grecs, Batiki et Rhoditis, sur leur teneur en composes soufres volatils. Il est demontre que le stade du sulfitage des vins nouveaux joue un role important sur la formation de ces substances, ainsi que l’aeration qui entraine leur diminution. De plus, la conservation des vins en barrique ou en cuve, avec les lies ou non, influence d’une maniere differente la teneur des vins en substances soufrees volatiles. Influence of white wine conservation conditions on the levels of volatile sulphur compounds In the present study, the effects of various parameters of white wine conservation on the level of volatile sulphur compounds were examined. Wines from the Greek white cvs Batiki and Rhoditis were fermented. H2S was analysed colorimetrically, the more volatile sulphur compounds by headspace-gas chromatography (GC) coupled with flame photometry detection (FPD) and the less volatile sulphur compounds by liquid extraction-GC/MS. The best time to sulphurize a young wine is 5-6 d after the end of alcoholic fermentation in order to avoid the accumulation of sulphur substances, especially in wines intended to age on lees, Aeration of wine causes a notable decrease of the more volatile sulphur compounds, whereas the diminution is less important for the less volatile sulphur compounds. Furthermore, the amount of volatile sulphur compounds is affected by the conservation of wines in barriques or in stainless tanks, the duration of contact of wine with its lees, as well as the duration of conservation.

Aromatic evolution of wine packed in virgin and recycled PET bottles

The evolution of the aromatic profile of a rosé wine packed in glass, virgin and recycled PET bottles was studied. Wine stored in PET and glass bottles was clearly differentiated after 5months of storage but only by a limited number of compounds. More pronounced decrease of oxygen sensitive compounds such as methionol was observed in PET bottles as well as the apparition of oxidative and ageing aroma compounds such as ethyl pyruvate, furfural or dioxanes in higher concentration. Compared to virgin PET bottles, recycled PET bottles induced slight changes favouring the presence of esters and alcohols. The chemical evolution of wine was the most important phenomenon that explains the loss of flavour rather than the sorption into PET. Because of their moderate oxygen permeability, the use of virgin PET and recycled PET bottles could be adapted for short conservation of wine but detrimental to aromatic quality if long conservation is intended.

Assessment of Aboveground Winery Buildings for the Aging and Conservation of Wine

Every year the wine sector moves billions of Euros around the world. In the high-quality wine production process, the temperature and relative humidity in the winery during the aging process have a decisive impact on the wine's final quality and on wine loss due to evaporation. To carry out the aging and conservation of wine, aboveground facilities are the most common solutions. This article studied how aboveground constructions without air condition systems respond to changes in the ambient conditions, analyzing the resulting indoor conditions. For this purpose, a study based on data obtained from a winery over several years was conducted. A simulation analysis to evaluate the thermal behavior in different wine-producing areas of the world was also performed. Results showed that the hygrothermal conditions in the cask facilities can go well beyond acceptable limits, especially during the summer months. The high temperature and low relative humidity could lead to rapid aging of the wine, reducing the quality and increasing wine losses. Moreover, we have demonstrated that the temperature and relative humidity stratification varied depending on the time of year, which has a direct impact on the handling of the wine and the number of casks levels used by winemakers. The results of this study could be used in the design of new wineries.

An assessment of using ground thermal inertia as passive thermal technique in the wine industry around the world

Abstract The main objective of this research is to promote passive thermal design techniques in the construction of wineries. We analyze the suitability of using the thermal inertia of the ground that surrounds underground cellars to provide an adequate ambience for the ageing and conservation of wine. For this purpose, a modelling procedure to simulate the annual temperature cycle inside the cellar was developed. The proposed model was validated using experimental air temperature data from wine cellars in Spain. Many of the main wine-producing regions of the world have been analyzed by means of the model. Results show that underground cellars have advantages for the ageing and conservation of wine in all regions studied because of the thermal inertia of the ground and its ventilation behaviour. By adjusting the depth according to the ground properties and exterior conditions, ideal temperature can be reached inside the cellar without air-conditioning expenses. The modelling procedure and the results data could be a great help in the study and design of new wine cellars or constructions with similar characteristics, making it possible to estimate the indoor temperature and select the location and most suitable parameters.

The influence of packaging on wine conservation

The aim of this work was to study the evolution of wine quality in different packaging configurations. An analysis was carried out of the influence of packaging on the sensory characteristics of red and white wine over an 18 months period. Glass bottles, Bag in Box®, and polyethylene terephthalate bottles were used in this investigation. Several different volumes were also investigated (18.5 cL, 75 cL and 300 cL). Usual enological parameters including gas content (O2, CO2), specific oxidation compounds were monitored, and sensory analyses, were carried out over the 18 months. Significant differences were brought to light as a function of the different packaging configurations. White wine was noticeably affected after 6 months of conservation in polyethylene terephthalate bottles. In polyethylene terephthalate bottles containing an oxygen scavenger as well as in a Bag in Box® container, the results were much closer to those noted in glass bottles. No significant differences were noted for red wine. So, packaging has a significant impact on the evolution of white wine during storage. These results constitute indicators to be taken into account when choosing packaging as a function of the mode of distribution and marketing envisaged.

Metals in Wine—Impact on Wine Quality and Health Outcomes

Metals in wine can originate from both natural and anthropogenic sources, and its concentration can be a significant parameter affecting consumption and conservation of wine. Since metallic ions have important role in oxide-reductive reactions resulting in wine browning, turbidity, cloudiness, and astringency, wine quality depends greatly on its metal composition. Moreover, metals in wine may affect human health. Consumption of wine may contribute to the daily dietary intake of essential metals (i.e., copper, iron, and zinc) but can also have potentially toxic effects if metal concentrations are not kept under allowable limits. Therefore, a strict analytical control of metal concentration is required during the whole process of wine production. This article presents a critical review of the existing literature regarding the measured metal concentration in wine, methods applied for their determination, and possible sources, as well as their impact on wine quality and human health. The main focus is set on aluminum, arsenic, cadmium, chromium, copper, iron, manganese, nickel, lead, and zinc, as these elements most often affect wine quality and human health.

Wine Oxidation and the Role of Cork

The present review aims to show the state of the art of oxidation mechanisms occurring especially in white wines by taking into account knowledge from different fields in relation to the subject. It is therefore divided into three main parts. First, the mechanisms of oxidation relevant to white wine are discussed in the light of recent scientific literature. Next, the phenomenon of oxygen solubility in wine during the winemaking process, and in particular during bottling is stated theoretically as well as practically. Finally, the aspect of wine conservation after bottling is examined with respect to mass transfers which may occur through the closure, with a special emphasis on cork. Currently, specific physico-chemical properties still make cork closures the most important closure type used for the wine market, and especially for high quality wines. This final section will also include a review of studies performed on this subject, which have been analyzed in detail from a theoretical mass transfer point of view, in order to assess the extent to which the proposed scientific tools and the observed tendencies are relevant to progress in the understanding of the impact of this parameter on the behavior of a wine.

New Method for Reducing the Binding Power of Sweet White Wines

Sulfur dioxide is now considered to be a toxic chemical by most world health authorities. However, it remains an irreplaceable additive in enology for wine conservation, combining antioxidant and antibacterial properties. Sweet white wines from botrytized grapes retain particularly high SO 2 levels due to their high sulfur dioxide binding power. This paper presents a new method for reducing this binding power by removing some of the carbonyl compounds responsible, which are naturally present in these wines. The main carbonyl compounds responsible for the SO 2 binding power of sweet wines were removed, that is, acetaldehyde, pyruvic acid, 2-oxoglutaric acid, and 5-oxofructose. The method retained was selective liquid-solid removal, using phenylsulfonylhydrazine as a scavenging agent. The scavenging function was grafted on different classes of porous polymer supports, and its efficiency was evaluated on sweet white wines under conditions intended to conserve their organoleptic qualities. The results obtained showed that the method was efficient for removing carbonyl compounds and significantly reduced the binding power of the wines. Sensory analysis revealed that this process did not deteriorate their organoleptic qualities.

Effect of storage conditions on the volatile composition of wines obtained from must stabilized by PEF during ageing without SO2

Abstract The aim of this work was to study the effect of the storage conditions on the evolution of volatile composition of white wines aged in bottles without the addition of SO 2 . Therefore Parellada must was stabilized by pulsed electric fields (PEF) and fermented without the employment of SO 2 and later on the wine was aged in bottles, without addition of this preservative, at low and controlled temperature and at room temperature. The obtained results showed that the concentration of some important compounds for wine aroma such as isoamyl acetate, and ethyl esters of fatty acids was higher in the wines stored at low and controlled temperature than in those aged at room temperature. However, the temperature favoured the formation of total alcohols during the aging of wines in the bottles. Consequently, from the point of view of the aromatic quality, the conservation of white wines obtained from fermentation of must processed by PEF and aged in bottles without the addition of SO 2 was improved under controlled storage conditions than at room temperature. Industrial relevance SO 2 is used as a preservative agent in wine due to its multi-action in the wine conservation. Although neither carcinogenicity nor mutagenic effects have been found in SO 2 , this compound has an influence on human health. For that reason, several competent international organizations (WHO, FAO, OIV) have set down maximum limits for wines as well as promote a reduction of its concentration in wines. Therefore, potential industrial applications of this work include the possibility to produce and store wines without SO 2 . This has been achieved by stabilizing the musts with PEF. The wines produced under these conditions can be conserved without this additive when used under controlled conditions of storage.

Generation of (E)-1-(2,3,6-Trimethylphenyl)buta-1,3-diene from C13-Norisoprenoid Precursors

Three C(13)-norisoprenoid compounds, 3,6,9-trihydroxymegastigma-4,7-diene (6), 3,4,9-trihydroxymegastigma-5,7-diene (4), and the actinidols (8), have all been synthesized and subjected to acid hydrolysis. All three were shown to generate (E)-1-(2,3,6-trimethylphenyl)buta-1,3-diene (1) under wine conservation conditions. At 45 degrees C, approximately 4000-5000 ng/L of 1 was formed from 1.0 mg/L of precursor, after 173 days, while at 25 degrees C more wine-like amounts (200-600 ng/L) were observed. A glucoside, 4,5-dihydrovomifoliol-C(9)-beta-d-glucopyranoside (9b), was isolated from grapevine leaves by multilayer coil countercurrent chromatography (MLCCC), and its stereochemistry was deduced as being (5R, 6S, 9R) by NMR and CD spectroscopy. Hydrolysis of this glucoside produced 1, but in quantities insufficient to account for the levels observed in wine.

Evaluation of the performances of synthetic and cork stoppers up to 24 months post-bottling

In recent years, as a consequence of higher market prices for cork and of the qualitative problems created by natural stoppers, the demand for alternative seals has increased remarkably . Since 1990, numerous manufacturers of plastic materials have begun production of synthetic stoppers for the closure of wine bottles. The application of the first experimental products was highly unsatisfactory and showed the need to carry out more research into the characterisation of the materials employed and their interaction with the "matrix wine". The object of this study was to estimate the mechanical characteristics of a particular kind of synthetic stopper and to compare the physico-chemical profiles of different Italian wines bottled with corks, or with synthetic stoppers made of expanded polyethylene, during the wine conservation phase. Analytical and statistical data produced give assurance that for these wine types, the employment of the synthetic stopper helps to increase the shelf-life of wines ready to consume within 1–2 years after bottling.

Polyphenols produced during red wine ageing.

Over the past few years, it has been accepted that a moderate red wine consumption is a factor beneficial to human health. Indeed, people of France and Italy, the two major wine-producing European countries, eat a lot of fatty foods but suffer less from fatal heart strokes than people in North-America or in the northern regions of Europe, where wine is not consumed on a regular basis. For a time, ethanol was thought to be the "good" chemical species hiding behind what is known as the "French paradox". Researchers now have turned their investigations towards a family of natural substances called "polyphenols", which are only found in plants and are abundant in grapes. It is well known that these molecules behave as radical scavengers and antioxidants, and it has been demonstrated that they can protect cholesterol in the LDL species from oxidation, a process thought to be at the origin of many fatal heart attacks. However, taken one by one, it remains difficult to demonstrate which are the best polyphenols as far as their antioxidant activities are concerned. The main obstacle in that kind of research is not the design of the chemical and biological tests themselves, but surprisingly enough, the limited access to chemically pure and structurally elucidated polyphenolic compounds. In this article, particular attention will be paid to polyphenols of red wine made from Vitis vinifera cultivars. With respect to the "French paradox", we address the following question: are wine polyphenolic compounds identical to those found in grapes (skin, pulp and seed), or are there biochemical modifications specifically taking place on the native flavonoids when a wine ages? Indeed, structural changes occur during wine conservation, and one of the most studied of those changes concerns red wine colour evolution, called "wine ageing". As a wine ages, it has been demonstrated that the initially present grape pigments slowly turn into new more stable red pigments. That phenomenon goes on for weeks, months and years. Since grape and wine polyphenols are chemically distinct, their antioxidant activities cannot be the same. So, eating grapes might well lead to beneficial effects on human health, due to the variety and sometimes large amounts of their polyphenolic content. However, epidemiological surveys have focused on wines, not on grapes....