Maria del Alamo-Sanza

American oak is widely used in enology, but its interactions with white wine and the role of wood properties remain poorly understood. In this study, oxygen dynamics and changes in the phenolic composition of wines made from the Verdejo, Albillo, Rufete, and Puesta en Cruz varieties were evaluated over 35 days of contact with toasted pieces from two Quercus alba wood samples with contrasting grain widths. Untreated control wines and a model wine treated separately with each wood were also included. Wood density and impregnation were determined, dissolved-oxygen partial pressure was monitored noninvasively, and routine enological parameters, spectrophotometric indices, and low-molecular-weight phenolic compounds were analyzed in the final wines. Contact with wood modified the net dissolved-oxygen profiles, although the relative effects of the two contrasting wood samples depended on the wine matrix. The fine-grain wood tested showed greater impregnation and generally produced higher phenolic indices, larger changes in color, and higher concentrations of several wood-derived compounds. Overall, the results show that the properties of the two wood samples and wine composition jointly shape the response of white wines to oak contact.

Background: Oak barrels are widely used in wine and spirit aging, where oxygen transmission plays a key role in the development of chemical and sensory properties. In cooperage, stave selection is traditionally based on grain width; however, the extent to which grain and wood macrostructure determine oxygen transmission under barrel conditions remains poorly understood, particularly for American oak. Results: The macrostructure and oxygen transmission rate (OTR) of 214 American oak ( Quercus alba ) staves were characterized under conditions simulating barrel use, with wood exposed to air on one side and a model wine solution on the other. Macrostructural parameters – density, porosity, growth‐ring features, earlywood and latewood widths and ratios, medullary ray characteristics, impregnation, and grain – were quantified by image‐based analysis and related to OTR. Compared to previously reported French oak ( Quercus petraea ), American oak showed higher density, lower porosity, wider growth rings, and greater interannual growth variability. OTR values varied substantially among staves and were on average approximately 68% lower than those reported for French oak. Grain showed only a weak relationship with OTR, and staves with similar grain displayed markedly different oxygen transmission. Multivariate analysis indicated that OTR is not controlled by any single macrostructural parameter but results from the combined effects of wood anatomy, growth patterns, structural orientation, and liquid impregnation. Conclusion: These findings highlight the limitations of traditional cooperage descriptors for predicting oxygen transmission and provide a basis for improved wood selection targeting specific oxygenation profiles. with direct implications for barrel choice and wine quality. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Sparging is a common technique in wineries that consists of injecting a gas, normally before bottling, in order to displace the dissolved oxygen in the wine and prevent oxidation. The objective of this study was to examine the effect of sparging on wines with three different levels of dissolved oxygen and the evolution of the chemical parameters in a bottle. This study was carried out on two white wines, Verdejo and Sauvignon blanc. The results indicated that sparging did not immediately affect the chemical parameters in the white wines, but it did affect their evolution in bottles, with a greater effect found in the Sauvignon blanc wines than in the Verdejo wines. Sparging, which was carried out to remove oxygen from the wines, had a protective effect on their color during the time in the bottles, preventing a more rapid decrease in free SO₂. The effect of sparging on the volatile compounds of the wines was more evident in the Sauvignon blanc wines, which showed a reduction in their content, possibly due to carry-over when the N₂ was applied. With regard to the effect of sparging on the sensory profile of the wines, no immediate effect was found. However, the wines with a DO content of 6 and 8.4 mg/L to which sparging was applied evolved better in the bottles than the deoxygenation wines, showing more fruity notes and fewer oxidized and phenolic aromas (mainly in the Verdejo wines).

In recent decades, the use of wood pieces has been promoted as a viable alternative to barrels to improve the quality of white wines. However, most available studies have focused on red wines. Given that white and red wines present significant oenological differences that affect their development and final characteristics, it is necessary to expand research specifically to the case of white wines. For this reason, this study evaluates the impact of using pieces of traditional oak wood (Quercus petraea (two origins: French and Romanian) and Quercus alba), other oaks (Quercus humboldtti and Quercus candicans) and other genera (Robinia pseudoacacia, Acacia dealbata, Prunus avium and Nothofagus pumilio) on the quality of white wine during the short period of contact with the wood. The results show that aging with the different woods has little effect on the oenological parameters of the wine; however, it does lead to a change in the phenolic composition and in the final chromatic characteristics of the white wines. From a sensory point of view, the wines showed different sensory profiles depending on the type of wood used. In general, the tasting panel preferred the white wine aged with French Quercus petraea wood pieces, followed by the wine aged with Quercus humboldtti wood pieces and the wine aged with Robinia speudoacacia wood pieces. This research improves our understanding of the potential impact of using pieces of different woods in white wines, describing the potential interest of some that have not been studied before, such as Quercus humboldtti.

The effects of SEGs (“Shoot from vines—Enological—Granule”) on winemaking within the same variety are well established. However, the interaction of different SEG varieties combined with micro-oxygenation (MOX) and its subsequent evolution in the bottle has not been investigated to date. In this work, Tempranillo wines were treated with two doses of SEGs from Tempranillo and Cabernet Sauvignon (12 and 24 g/L) and subjected to two fixed MOX doses (LOTR, 6.24 mg/L·month, and HOTR, 11.91 mg/L·month). After that, the wines were bottled, and their chemical composition and sensory profile were analysed after 3 and 6 months. Although no clear trend directly associated with the use of MOX was observed, in terms of chemical composition, wines showed an evolution in their chemical profile over time, with compounds such as vanillin increasing as more oxygen was added. Regarding their sensorial profile, the wines were more rounded after 6 months that in bottling, where SEGs or toasted descriptors, studied at the taste phase, were slightly more intense with the low SEG dose and HOTR combination.

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.

Sparging is a technique to remove an excess of dissolved oxygen from the wine with inerting gases before bottling to avoid negative consequences for its chemical and sensory properties. However, its effectiveness on these properties has not been studied in depth. This work investigates the effectiveness of different inerting gases (N₂, CO₂, and argon) in removing dissolved oxygen in different volumes of a model wine. The efficacy of these gases was also studied in white and red wine, as was their effect on the physicochemical characteristics. Sparging with N₂ in the model wine gave the best results in terms of cost–benefits, and with CO₂ the worst. The scaling in tanks of different sizes allowed us to establish that the N₂ expenditure ranged between 0.09 L and 0.23 L of gas per liter of model wine, establishing an index (L_gas/L_wine) that can be very useful for wineries to remove the dissolved oxygen. Sparging treatments in white and red wine showed very similar results to the model wine. The effect on the chemical properties of the wines was, in some cases, different for white and red wine and for each gas used. The incorporation of oxygen and the subsequent sparging produced a significant loss of some volatile compounds of sensory interest and increased the content of others that have a negative sensory effect. In addition, it had a negative effect on the chromatic properties of red wines.