Oxygen Consumption by Red Wines under Different Micro-Oxygenation Strategies and Q. Pyrenaica Chips. Effects on Color and Phenolic Characteristics

Chemical and sensorial profile of Tempranillo wines elaborated with toasted vine-shoots of different varieties and micro-oxygenation

The positive impact of use SEGs ("Shoot from vines - Enological - Granule") in winemaking for wines of the same variety has been extensively demonstrated, but their combination with different SEGs varieties and micro-oxygenation (MOX) remains unstudied. In this study, Tempranillo wines were in contact along 35 days with two doses of Tempranillo and Cabernet Sauvignon SEGs (12 and 24 g/L) and two fixed doses of MOX (LOTR, 6.24 mg/L·month, and HOTR, 11.91 mg/L·month). Chemical composition and sensory profiles were analyzed after SEGs-MOX treatments. Results indicated a greater impact of MOX on volatile composition when Cabernet Sauvignon SEGs were used, with similar results for CS12-HOTR and CS24-LOTR wines. Phenolic compounds showed a total concentration decrease in all treated wines, though trans-resveratrol increased in all cases, particularly with the highest MOX dose. In sensory evaluation, MOX accelerated the integration of characteristic SEGs aromas into the wine, reducing the required bottle time for round them.

New System for Simultaneous Measurement of Oxygen Consumption and Changes in Wine Color

The design, construction and validation of a device for the accurate measurement of the dissolved oxygen content in wine and simultaneously the variation of its spectral fingerprint is presented. The novelty of this system is due to two innovative approaches. First, robustness in measurements is obtained by using cuvettes designed to simultaneously measure the dissolved oxygen and color. Secondly, automatic monitoring is performed to ensure that measurements are always taken at the same cuvette position. The fine-tuning of the device with the study of white and red wines makes it possible, on the one hand, to establish the appropriate measurement conditions and, on the other hand, to determine the amount of oxygen required to cause specific changes in the wine spectrum, information that could not be obtained until now. The preliminary results are very interesting, presenting precise data on the amount of oxygen consumed by the wine and the variations in its visible spectrum, thus reflecting the modification of the responsible phenolic compounds. This information is of great interest, since it helps to optimize the handling of the wine and, if necessary, to moderate the uptake of oxygen in each type of wine to ensure the maintenance of the color during the winemaking and conservation processes of each type of wine. The results of the experiments indicate that this new instrument is feasible and accurate for detecting oxygen changes during wine production.

Influence of Oxygen Management on Color and Phenolics of Red Wines

Winemaking involves contact at different stages with atmospheric oxygen, the consumption of which determines its final properties. The chemical analysis of red wines subjected to consecutive cycles of air saturation has been extensively researched; however, the capacity to consume different doses of oxygen before bottling is an aspect that has been little studied. In this work, the effect of saturation of different levels of oxygen on the final characteristics of different wines made from Tempranillo and Garnacha grape extracts was studied. For this purpose, the wines were subjected to controlled oxygen saturation levels to simulate their possible oxygenation before bottling. The only difference was the phenolic composition of grape extracts that were reconstituted under the same conditions to avoid the interferences inherent to the fermentation process and the additives added in the winery. The kinetics of oxygen consumption was then evaluated and its effect on the color, antioxidant capacity, and phenols of three different wines was analyzed. This work shows the relationship between the oxidation state of wine and changes in its chemical composition. In addition, it provides insight into the effect of oxygen consumption before bottling on the properties of wines subjected to high and single doses of oxygen.

The Application of Wood Species in Enology: Chemical Wood Composition and Effect on Wine Quality

Aging wine is a usual practice in winemaking, as the wine quality improves due to the compounds extracted from wood barrels or chips, cubes, blocks, or staves used. The wood species used are traditionally oak, namely from Quercus petraea, Q. alba, or Q. robur species. In the last years, the increasing request for oak wood has caused a significant increase in environmental and production costs. Therefore, heartwood from several alternative species has been considered a potential wood source for winemaking and aging. Thus, the main purpose of this review is the application of these alternative wood species on wine production and to discuss the advantages and disadvantages of its use compared with the traditional wood species, namely oak wood. In addition, a brief chemical characterization of several wood species with possible application in enology is also discussed in this review.

Red Wine Aging by Different Micro-Oxygenation Systems and Oak Wood—Effects on Anthocyanins, Copigmentation and Color Evolution

The micro-oxygenation (MOX) of aged wine in contact with pieces of wood is a technique widely used for aging wines as an alternative to barrels. The available range of passive MOX systems is very wide and offers a behavior closer to that of barrels because it uses materials with a similar permeability to oxygen. The aim of this work has been to age the same red wine for 6 months using the main passive MOX systems and compare them with the classic MOX in stainless steel tanks and with barrels as a reference, in order to evaluate phenolic composition and establish its influence. The quantity and the way in which oxygen is incorporated into wine have been found to determine its evolution and final properties. Wine from barrels could be distinguished throughout the aging period since a better level of individualized anthocyanins was maintained, whereas stainless steel + MOX and PMDS (polydimethylsiloxane) wines presented more bluish hues.

Wine Aging Technology: Fundamental Role of Wood Barrels

The aging of wines is a process used to preserve wine but also to enhance its properties. It is a process of great interest, mainly because of the additional properties it adds to wines and because of its economic implications. Historically, barrels have been employed for centuries for preserving and aging wine due to their resistance and relative impermeability. In general terms, the wine aging process can be divided into two phases: oxidative and reductive aging. Oxidative aging traditionally takes place in barrels while reductive phase occurs in the bottle. During both processes, oxygen plays a fundamental role as well as other factors, for instance: temperature, light, bottle position, microbial growth or storage time. Likewise, during the aging process, a series of chemical reactions take place influencing the composition and organoleptic profile of wine. At this point, oxidative aging in barrels is a fundamental step. Barrels are directly involved in the produced changes on wine's composition due to the transference of oxygen and phenolic and aromatic compounds from wood to wine. This way, barrels act as an active vessel capable of releasing compounds that affect and improve wine's characteristics. Regarding, the importance of barrels during aging process, some attention must be given to the species most used in cooperage. These species are conventionally oak species, either French or American. However, other non-conventional species are currently being studied as possible wood sources for the production of wines, such as chestnut robinia or other oak species. In the last decades, new approaches have been developed for barrel aging to find new alternatives more suitable, affordable and feasible to sanitize the process, such as other materials different from wood or the use of wood chips, which is regulated since 2006 by the EU. However, even though some of them have shown promising data, barrels are currently the most used technology for the oxidative stage of table wines aging.

The Use of a Targeted Must Oxygenation Method in the Process of Developing the Archival Potential of Natural Wine

We examined the effect of two different technological processes for wine production on qualitative parameters of wine. We used the reductive method, which is currently considered to be the conventional method, and a targeted must oxidation method. We evaluated the basic physicochemical parameters and sensory attributes of wine as well as the content of phenolic substances in wine, which are responsible for the oxidation processes. The vegetable materials used were the grape varieties, Welschriesling, Chardonnay, and Rheinriesling. The content of phenolic substances was determined by HPLC (high-performance liquid chromatography), and the basic analytical parameters of wine were determined by FT-IR (Fourier Transform Infrared Spectroscopy) spectrometry. The sensory analysis was evaluated according to the International Union of Oenologists. For each of the wines examined, the total content of phenolic substances decreased after the targeted oxidation method was applied. For the Welschriesling variety produced by the reduction method, the total content of the 19 monitored phenolic substances in the year 2015 was 88.37 mg·L−1, and for the wine produced by target oxygenation, it was 68.63 mg·L−1. This represents a decrease of 21.5%. In the year 2016, the decrease was 20.91%. By reducing the content of phenolic substances, the oxidation processes in wines are eliminated after bottling. Thus, there is less need for sulphating wines with a reduced content of phenols.

Effect of size, seasoning and toasting level of Quercus pyrenaica Willd. wood on wine phenolic composition during maturation process with micro-oxygenation

Seasoning and toasting treatments carried out in cooperage influence the chemical composition of the oak, and these treatments affect different oak species in different ways. For this reason, numerous studies have focused on the evaluation of both the oak wood materials and the resulting aged wines in order to optimize the different cooperage processes. Seasoning involves immobilizing the wood for long periods of time, leading to an increase in the price of the final product. When using alternative products instead of barrels, in addition to the seasoning and toasting of the wood, the size of the wood pieces is a determining factor in the characteristics of the final wine. Therefore, the objective of this work was to evaluate the polyphenolic composition of the same red wine aged with different alternative products and a small amount of oxygen for 120 days. Specifically, the effect of 2 types of seasoning and 3 types of toasting of chips and staves made from the wood of Q. pyrenaica Willd. was studied. The results showed that the size of the alternative product was the factor that determines the phenolic composition of the wines over the entire ageing process, independent of the seasoning or toasting method carried out on the wood.

Wine Aging Technologies

Wine aging is a desirable and valuable process, commonly used to improve wine quality, and traditionally carried out in oak wooden casks [...]

Different Woods in Cooperage for Oenology: A Review

Contact of wine with wood during fermentation and ageing produces significant changes in its chemical composition and organoleptic properties, modifying its final quality. Wines acquire complex aromas from the wood, improve their colour stability, flavour, and clarification, and extend their storage period. New trends in the use of barrels, replaced after a few years of use, have led to an increased demand for oak wood in cooperage. In addition, the fact that the wine market is becoming increasingly saturated and more competitive means that oenologists are increasingly interested in tasting different types of wood to obtain wines that differ from those already on the market. This growing demand and the search for new opportunities to give wines a special personality has led to the use of woods within the Quercus genus that are different from those used traditionally (Quercus alba, Quercus petraea, and Quercus robur) and even woods of different genera. Thus, species of the genus Quercus, such as Quercus pyrenaica Willd., Quercus faginea Lam., Quercus humboldtti Bonpl., Quercus oocarpa Liebm., Quercus frainetto Ten, and other genera, such as Robinia pseudoacacia L. (false acacia), Castanea sativa Mill. (chestnut), Prunus avium L. and Prunus cereaus L. (cherry), Fraxinus excelsior L. (European ash), Fraxinus americana L. (American ash), Morus nigra L, and Morus alba L. have been the subject of several studies as possible sources of wood apt for cooperage. The chemical characterization of these woods is essential in order to be able to adapt the cooperage treatment and, thus, obtain wood with oenological qualities suitable for the treatment of wines. This review aims to summarize the different species that have been studied as possible new sources of wood for oenology, defining the extractable composition of each one and their use in wine.