Macrowine 2021
IVES 9 IVES Conference Series 9 Effect of post-harvest ozone treatments on the skin phenolic composition and extractability of red winegrapes cv Nebbiolo and Barbera

Effect of post-harvest ozone treatments on the skin phenolic composition and extractability of red winegrapes cv Nebbiolo and Barbera

Abstract

Wine industry is looking forward for innovative, safe and eco-friendly antimicrobial products allowing the reduction of chemical treatments in the grape defense and the winemaking process that can affect negatively the quality of the product. Ozone has been tested in food industry giving good results in preventing fungi and bacteria growth on a wide spectrum of vegetables and fruits, due to its oxidant activity and ability to attack numerous cellular constituents. Ozone leaves no chemical residues on the food surface, decomposing itself rapidly in oxygen. Gaseous ozone has been already tested for table grapes storage and on wine grapes during withering. In particular, ozone has been suggested as phenolic compounds elicitor, stimulating chemical defense mechanisms such as the synthesis of polyphenols, and as enhancer of cellular membrane and cell walls degradation phenomena. Phenolic compounds are strongly linked to the red wine quality, and their extraction depends on the grape variety, winemaking technique and cell wall degradation. In this work, Vitis vinifera L. cv Nebbiolo and Barbera, chosen for their different anthocyanin profiles, were post-harvest treated for 24 and 72 hours with gaseous ozone (30 µL/L). Untreated samples were used as control with the aim of investigating possible indirect physico-chemical effects of this sanitizing treatment on berry skin phenolic composition. Skin phenolic extractability was assessed during maceration (6, 24, 48, 96, 168 and 240 hours) using a wine-like solution, particularly for total anthocyanins (TA), proanthocyanidins (PRO) and flavanols reactive to vanillin (FRV), and anthocyanin profiles were also determined. Ozone did not affect significantly the final extraction yield of TA, PRO and FRV in Barbera; although anthocyanin extractability was higher in control rather than in ozone-treated samples during the first stages of maceration. Otherwise, Nebbiolo was positively influenced by the treatment because ozone increased significantly TA extraction (68.6, 64.2 and 59.9% for 24 hours ozone-treated berries, 72 hours ozone-treated berries and control samples, respectively). PRO and FRV extractability also showed an increase in both ozone-treated samples compared to the control (+8.6-9.1% for PRO and +7.3-11.7% for FRV). No significant differences were found among treatments for individual anthocyanins, whereas the variety and maceration time strongly affected the anthocyanin profile. In our experimental conditions, ozone enhanced phenolic compounds extractability in Nebbiolo grapes while it did not show significant effects on Barbera. Therefore, the use of ozone as sanitizing agent in the red varieties winemaking process can be considered because it did not negatively affect the extractability of skin anthocyanins and flavanols.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Maria Alessandra Paissoni*, Cristian Carboni, Fabrizio Torchio, Francesco Cravero, Kalliopi Rantsiou, Luca Cocolin, Luca Rolle, Pierre-Louis Teissedre, Simone Giacosa, Susana Río Segade, Vasileios Englezos, Vincenzo Gerbi

*Università di Torino

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Effect of malolactic fermentation in barrels or stainless steel tanks on wine composition. Influence of the barrel toasting

Ellagitannin, anthocyanin and woody volatile composition of Cabernet Sauvignon wines aged in oak barrels for 12 months was evaluated. Depending on the container where malolactic fermentation (MLF) was carried out, two wine modalities were investigated: wines with MLF carried out in stainless steel tanks and barrel-fermented wines. Three toasting methods (medium toast, MT; medium toast with watering, MTAA; noisette) were considered for ageing of each wine modality. Sensory analyses (triangle and rating tests) were also performed. Two-way ANOVA of the raw experimental data revealed that the toasting method and the container where MLF took place, as well as the interaction between both factors, have a significant influence (p < 0.05) on ellagitannin, anthocyanin and woody volatile profiles of Cabernet Sauvignon wines.

Quantification of the production of hydrogen peroxide H2O2 during wine oxidation

Chemical studies aiming at assessing how a wine reacts towards oxidation usually focus on the characterization of wine constituents, such as polyphenols, or oxidation products. As an alternative, the key oxidation intermediate hydrogen peroxide H2O2 has never been quantified, although it plays a pivotal role in wine oxidation. H2O2 is obtained from molecular oxygen as the result of a first cascade of oxidation reactions involving metal ions and polyphenols. The produced H2O2 then reacts in a second cascade of oxidation to produce reactive hydroxyl radicals that can attack almost any chemical substrate in wine.

Use of glutathione under different grape processing and winemaking conditions and its impact on the formation of sulfide off-flavors, colour, and sensory characteristics of Riesling, Sauvignon blanc, and Chardonnay

The use of glutathione (GSH) in winemaking has been legitimated recently, according to OIV resolutions OENO 445-2015 and OENO 446-2015 a maximum dose of 20 mg/L is now allowed to use in must and wine. Several studies have proven the benefits of GSH, predominantly in Sauvignon blanc. Thus, oxidative coloration of must and wine is limited, aroma compounds such as volatile thiols are preserved, and the development of ageing flavors such as sotolon and 2-aminoacetophenone is impeded. The protective effect may be explained by the high affinity of GSH to bind o-quinones which are formed during phenolic oxidation and which are known to initiate browning and other oxidative changes. Some researchers have proposed the hydroxycinnamic acid to GSH ratio (HGR) as an indicator of oxidation susceptibility of must and could show that lower ratios yielded lighter musts.

Effects of post-fermentative cold maceration on chemical and sensory characteristics of Syrah, Cabernet Franc and Montepulciano wines

Astringency sensation decreases slowly during the aging of red wine. Complex reactions of condensation and precipitation of wine polyphenols are involved in this phenomenon. Wine composition and conditions of aging, such as temperature and oxygen availability, strongly influence evolution of the phenol matrix. Recently, a Post-Fermentative cold Maceration (PFM) technique was tested with the aim of accelerating reactions leading to the reduction of astringency and exploiting chemical compounds not extracted from the solid parts of grapes during the previous traditional maceration phase. To this purpose, an innovative maceration system was engineered and used to perform PFM trials on marc derived from vinification of different varieties of red grapes.

The impact of different yeasts and harvest time on the wine quality of Beihong and Beimei (<I>V. vinifera x V. amurensis</I>)

Beihong and Beimei are two wine cultivars from ‘Muscat Hamberg’ (V. vinifera L.) and wild V. amurensis Rupr., which were released in China in 2008. Here,two enology practices were reported. Firstly, the impact of different yeasts including D254, GRE, K1, D21 and BDX on dry wine quality of Beihong and Beimei was investigated. For Beihong, among wines fermented by all yeasts, residual sugar content was the lowest, total anthocyanin and resveratrol contents were the highest in the wine by D254. However, the wine by D254 had lower titrable acid than those by the other yeasts except BDX.