 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

Predictive Breeding for Wine Quality: From Sensory Traits to Grapevine Genome

New pathogen resistant varieties allow an efficient and greatly reduced use of fungicides. These new varieties promise, therefore, an enormous potential to reach the European Green Deal aim of a 50% reduction of pesticides in EU agriculture by 2030.

Optimized protocol for high-quality RNA extraction from grape tissues using sorbitol pre-wash

Obtaining high-quality RNA from grape tissues, including berry pulp, berry skins, stems, rachis, or roots, is challenging due to their composition, which includes polysaccharides, phenolic compounds, sugars, and organic acids that can negatively affect RNA extraction. For instance, polyphenols and other secondary metabolites can bind to RNA, making it difficult to extract a pure sample. Additionally, RNA can co-precipitate with polysaccharides, leading to lower extraction yield. Also, sugars and organic acids can interfere with the pH and ionic properties of the extraction buffer. To address these challenges, we optimized a protocol for RNA isolation from grape tissues.

Vitiforestry as innovative heritage. Adaptive conservation of historical wine-growing landscapes as response to XXI century’s challenges.

Traditional agricultural and agro-pastoral systems (prior to industrial revolution) often have the characteristic of being multiple systems, in which multiple crops are hosted simultaneously on the same plot. currently research suggests to study more in depth the potential of multiple agricultural systems in order to detect those characteristics of multiple agrarian systems that could allow modern viticulture to adapt to the challenges posed by climate change: rising temperatures with impacts on the phenological cycle of the vine, resurgence of plant deseases, extreme soil washout phenomena and hail storms, among others.

Temperature variability assessment at vineyard scale: control of data accuracy and data processing protocol

Climatic variability studies at fine scale have been developed in recent years with the reduction of material cost and the development of competitive miniaturized sensors. This work is forming part the LIFE-ADVICLIM project, of which one of the objectives is to model spatial temperature variability at vineyard scale. In the Bordeaux pilot site, a large network of data loggers has been set up to record temperature close to the vine canopy. The reduced distance between plant foliage and measurement equipment raises specific issues and leads to an increased rate of outliers compared to data retrieved from classical weather stations. Some of these were detected during data analysis, but others could not be easily identified. The present study aims to address the issue of data quality control and provide recommendations for data processing in climatic studies at fine scale.

New insights on thiol precursors catabolism by yeast during wine fermentation: identification of the N-Acetyl-L-Cysteine conjugate

Understanding the catabolism of thiol precursors is essential for understanding the revelation of varietal thiols in wine. For many years, knowledge of these precursors has been limited to the S-conjugates of glutathione, cysteine (Cys3SH) and the dipeptides g-GluCys and CysGly, without being able to explain the full origin of 3-sulfanylhexan-1-ol (3SH) in wines