Micro‑oxygenation in red wines: Current status and future perspective

Micro‑oxygenation (MOX) is the technology providing a slow and continuous oxidation reaction in the whole winemaking process to improve wine quality. However, traditional methods of oxygen management struggle to achieve a precise control over oxygen at critical process points, failing to meet the personalized and diverse production demands of wine. In this paper, an overview of three application stages of MOX, and the detailed dosage and duration at each stage were summarized. In addition, the application prospect of the new MOX application facility in wine production was proposed. Compared to passive MOX, active MOX could allow a more precise control of oxygen. The innovation of MOX equipment based on active MOX technique will be an inspiring interest in the research of winemaking. The integration and development of precise MOX will achieve the targeted control of wine quality and the creation of distinctive characteristics of wine style.

Effect of micro-oxygenation on color of wines made with toasted vine-shoots

BACKGROUND

Toasted vine-shoots (SEGs) are an enological tool to improve wines, to differentiate them, and to encourage sustainable wine production. Micro-oxygenation (MOX) is typically combined with the use of alternative oak products to simulate the oxygen transmission rate of traditional barrel aging, affecting wine color. Its use alongside SEGs has been studied.

RESULTS

Tempranillo wines were treated with SEGs at two doses (12 and 24 g L-1) after malolactic fermentation at two fixed micro-oxygenation levels: (a) low, which received 6.24 ± 0.87 mg L-1·month-1 of oxygen; and, (b) high, which received 11.91 ± 0.71 mg L-1·month-1 of oxygen. The wines were bottled and stored for 6 months. At the end of the treatment, MOX affected the anthocyanins and color parameters, but not the enological characteristics. At this time, the anthocyanins content reduction presented a negatively significant correlation with oxygen for wines treated with 12 g L-1. The factors that most influenced the development of color parameters during the time after bottling were the period for which the wine evolved in the bottle and SEG dose. The visual sensorial descriptors showed an evolution according to aged red wines, but without differences according to the SEG-MOX treatments.

CONCLUSION

The SEG-MOX treatments caused significant changes in wine color. It would be advisable to adjust SEG-MOX techniques to increase their effectiveness. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Evolution During Bottle Ageing of Wines Macerated with Toasted Vine-Shoots and Micro-Oxygenation

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.

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.

Advancements in the promotion of pyranoanthocyanins formation in wine: A review of current research

Pyranoanthocyanin (PACN) is a class of anthocyanin (ACN)-derived pigments found in aged red wines, which has certain advantages over the prototype ACN in terms of stability, and biological activity. However, the efficiency and yield of PACNs in the natural fermentation system are low. This article summarizes five frequently employed physical processing techniques that can accelerate the formation of PACN. From a mechanistic standpoint, these techniques can produce large amounts of active substances, further promoting the extracellular release of phenolics and the formation of some cofactors and PACNs' pyran rings. Precursor substances and environmental factors affecting PACN yields are also pointed out. It mainly included the parent ring substitution in ACNs, the type and quantity of glycosides, the electron donating ability and concentration of cofactors, etc. Thus, this article aims to provide an overview of the advancements in processing techniques, thereby facilitating their wider utilization in the food and beverage industry.

Replacement of SO2 with an Unripe Grape Extract and Chitosan during Oak Aging: Case Study of a Sangiovese Wine

The aim of this study was to evaluate the chemical, microbiological and sensory characteristics of a Sangiovese wine aged in barrique with the addition of an unripe grape extract (UGE) as an alternative to sulfur dioxide. Three samples were considered: control wine (TQ) with free SO₂ of approximately 15 mg/L; sample A with chitosan (100 mg/L) and UGE (200 mg/L); and sample B with UGE (400 mg/L). The results achieved in this work demonstrated that the UGE, either alone or in combination with chitosan, was able to maintain the color characteristics of the Sangiovese wine and its sensory quality. Moreover, the addition of UGE contributed to an early and better stabilization of the color through the formation of polymeric pigments. The microbiological stabilization was comparable to SO₂ when UGE was used at 200 mg/L in combination with chitosan. The market survey conducted in the present study confirmed how the use of UGE as an alternative to sulfitation was positively accepted by consumers, who are increasingly attentive not only to the quality of the wines they select but also to the sustainability of the production processes from which they derive and to the fact that they are not harmful to human health.