 IVES 9 IVES Conference Series 9 How the management of ph during winemaking affects acetaldehyde evolution and the formation of polymeric phenolics over the red wine aging

How the management of ph during winemaking affects acetaldehyde evolution and the formation of polymeric phenolics over the red wine aging

Abstract

AIM: The aim of this study is to evaluate the role of pH on both the acetaldehyde chemistry and wine phenolics evolution over the aging period. In addition, the effect of both an early (on musts) and late (on wines soon after the end of the fermentation) acidification was evaluated.

METHODS: The experimental design consisted in the preparation of 7 wines from the same batch of grapes fermented in a first tank at the original pH of 3.2 (3.2W) and two other tanks in which the pH was adjusted to 3.5 (3.5W) and 3.9 (3.9W). On the third day of fermentation, and one week after the end of the fermentation-maceration process some aliquots of both 3.5W and 3.9W were treated to reach a 3.2 pH to afford four more wines. Polymeric pigments and phenolics were evaluated by spectrophotometry, MS and NMR techniques, acetaldehyde and anthocyanins by HPLC-DAD and reactivity of tannins towards saliva by electrophoresis. Wines were analyzed soon after the end of the fermentation and after one-year aging.

RESULTS: By increasing the pH level from 3.2 to 3.9, the amount of low polymerized flavans, individual anthocyanins and tannins reactive to BSA and saliva decreased. Conversely, an increase of acetaldehyde, of pigments resistant to the bleaching, and of ethylene-linked polymeric pigments was detected. After one year of aging, wines treated to reach a 3.2 pH significantly differ from 3.2W in acetaldehyde, tannins reactive towards proteins and polymeric pigments. This behavior was more evident when the acidification was carried out soon after the end of the fermentation-maceration process.

CONCLUSIONS

High pH values favor the polymerization of phenolics over the wine aging and results suggested that the effect is predominant when pH was increased during the fermentation, hence successive pH modulations have little (if any) effect on some typical reactions occurring during wine aging.

DOI:

Publication date: September 14, 2021

Issue: Macrowine 2021

Type: Article

Authors

Angelita Gambuti

Department of Agricultural Sciences, University of Napoli “Federico II”- Enology Sciences Section, Viale Italia, 83100, Avellino, Italy, Luigi PICARIELLO, Department of Agricultural Sciences, University of Napoli “Federico II”- Enology Sciences Section, Viale Italia, 83100, Avellino, Italy. Martino FORINO, Department of Agricultural Sciences, University of Napoli “Federico II”- Enology Sciences Section, Viale Italia, 83100, Avellino, Italy Alessandra RINALDI, Department of Agricultural Sciences, University of Napoli “Federico II”- Enology Sciences Section, Viale Italia, 83100, Avellino, Italy. Biolaffort, 126 Quai de la Souys, 33100 Bordeaux, France. Luigi MOIO, Department of Agricultural Sciences, University of Napoli “Federico II”- Enology Sciences Section, Viale Italia, 83100, Avellino, Italy.

Contact the author

Keywords

red wine, aging, ph, polyphenols

Citation

Combining high-power ultrasound and oenological enzymes during winemaking for improving red wine chromatic characteristics

he use of high-power ultrasound (US) is proving of great interest to the oenological industry due to its effects in the improvement of wine organoleptic characteristics, especially in terms of color [1, 2].

Evaluation of physiological properties of grapevine clones of ‘Tempranillo’ and ‘Graciano’ in DOCa Rioja (Spain)

In order to avoid the loss of grapevine intra-varietal diversity of DOCa Rioja grape varieties, Regional Government of La Rioja established a germplasm bank with more than 1.600 accessions, whose origin lies in the prospecting and sampling of ancient vineyards located throughout the whole region. 30 clones of Tempranillo and 13 clones of Graciano were preselected and multiplied in a new vineyard for further observations. The aim of this work is to describe the first results from the physiological characterization by an optical sensor of these preselected clones, which constitute the base of a new clonal selection that aims to increase the range of available certified clones and to improve the adaptation of these varieties to future objectives and environmental conditions.

Le Pinot noir dans la zone AOC des “Colli Orientali del Friuli” (nord-est de l’Italie) : influence de la forme de taille sur les paramètres viticoles et œnologiques du raisin et du vin

Pinot noir is an interesting vat variety for the high quality products it provides in the most suitable areas. In France, the most important Pinot Noir growing areas are Burgundy, Champagne, Alsace and the Loire. In Italy, Pinot Noir is grown almost exclusively in the northern regions of Trentino-Alto Adige, Lombardy and Friuli-Venezia Giulia.

Sustainable management of grapevine trunk diseases

Grapevine trunk diseases (GTD) occur wherever grapes are grown and are considered the main biotic factor reducing yields and shortening vineyards’ lifespan. Currently, no product is available to eradicate GTD once grapevines are infected. Therefore, prophylactic strategies based on pruning wound protection and ‘remedial surgery’, the only eradication method based on the elimination of infected wood and renewal of the vine by means of new canes or suckers, are the only effective strategies available. The Canadian grape and wine industry focusses on a sustainable production and thus, looking for alternatives to chemicals for disease management is a top priority.

Resilience analysis in viticulture: an approach based on expert knowledge elicitation

The study aims to address the issue of resilience to climate change in viticulture through the adoption of the expert knowledge elicitation (EKE) approach.