 IVES 9 IVES Conference Series 9 Macrowine 9 Macrowine 2021 9 Grapevine diversity and viticultural practices for sustainable grape growing 9 Chemical composition of cool-climate Sauvignon blanc grape skins clones during ripening

Chemical composition of cool-climate Sauvignon blanc grape skins clones during ripening

Abstract

AIM: Sauvignon blanc is the most important variety in cool valleys in central Chile accounting 15,522 ha which corresponds to 42.4% of the cultivated surface with white varieties in Chile (SAG, 2019). Casablanca Valley, one of the most important area for the production of white wines in Chile is located approximately to 35-40 km from the Pacific Ocean. Still, geographical area and the clone utilized could be decisive for the chemical and sensory characteristics of this type of wine (Duchene et al., 2009; Green et al., 2011), both during ripening and during ageing of wine. For this reason, the aim of this work is to study the concentration and composition of phenolic compounds and organic acids throughout ripening in grape skins of Sauvignon blanc clones grown in two zones of Casablanca Valley.

METHODS: Sauvignon blanc clones 242, 1 Davis and 107 grown in two zones of the Casablanca Valley, central zone of Chile were chosen. The grape berries were sampled every 15 days from veraison until commercial harvest, using a completely randomized design with five replicates in each selected vineyard. The following chemical analyses were assessed: titratable acidity, total soluble solids, total phenols, CIELab coordinates, low molecular weight phenolic profile and organic acids using High Performance Liquid Chromatography (HPLC-DAD).

RESULTS: As expected, titratable acidity diminished during ripening while total soluble solids and pH increased in all clones. Total phenols decreased in all clones during ripening, with significant differences in their concentration between the two geographical zones. Low molecular weight phenolic compounds showed differences in concentration between Sauvignon blanc clones and geographical origin showed that the grapes grown in the zone more closed to the Pacific Ocean had a higher concentration of flavonols, while organic acids differed in concentration but not in composition between clones and geographical origin.

CONCLUSIONS

We observed differences in concentration on some chemical parameters between Sauvignon blanc clones that depends on the geographical origin, while its composition remains similar.

DOI:

Publication date: September 2, 2021

Issue: Macrowine 2021

Type: Article

Authors

Alejandro Cáceres

Faculty of Agronomic and Food Sciences, Pontificia Universidad Católica de Valparaíso, Chile.,Pierina Peirano Faculty of Agronomic and Food Sciences, Pontificia Universidad Católica de Valparaíso, Chile.

Contact the author

Keywords

Sauvignon blanc, flavonols, organic acids, cool-climate wines

Citation

The wine: a never-ending source of H2S and methanethiol

Volatile sulfur compounds (VSCs), mainly hydrogen sulfide and methanethiol (H2S and MeSH), are the responsible for reductive off-odor in wine.

FOLIAR APPLICATION OF METHYL JASMONATE AND METHYL JASMONATE PLUSUREA: INFLUENCE ON PHENOLIC, AROMATIC AND NITROGEN COMPOSITION OFTEMPRANILLO WINES

Phenolic, volatile and nitrogen compounds are key to wine quality. On one hand, phenolic compounds are related to wine color, mouthfeel properties, ageing potential. and are associated with beneficial health properties. On the other hand, wine aroma is influenced by hundreds of volatile compounds. Fermentative aromas represent, quantitatively, the wine aroma, and among these volatile compounds, esters, higher alcohols and acids are mainly responsible for the fermentation bouquet.

High resolution remote sensing for mapping intra-block vine vigour heterogeneity

In vineyard management, the block is considered today as the technical work unit. However, considerable variability can exist inside a block with regard to physiological parameters, such as vigour, particularly because of soil heterogeneity. To represent this variability spatially, many measurements have to be taken, which is costly in both time and money. High resolution remote sensing appears to be an efficient tool for mapping intra-block heterogeneity.

Update knowledge about the presence of condensed tannins in grapes and their contributions to astringency perception

Condensed tannin is a principle group of polyphenol compounds derived from grape, greatly contributing to the bioactivity and the sensory perception of wine. Condensed tannins present as a heterogeneous mixture in nature involving various degrees of both polymerization and galloylation. Even though multiple attempts focusing on fractionation of grape condensed tannins by solid-phase have been conducted over the past decades, few individual tannins have been purified and identified. Hence, our knowledge on grape and wine condensed tannin moleculars has to be limited at the several known monomeric, dimeric and trimeric proanthocyanidins

Solid Rectified Concentrated grape Must (SRCM) in sparkling wines production: studying the sensory impact of an innovative sugar substrate

The production of sparkling wines requires sugars for the second fermentation. The Solid Rectified Concentrated Must (SRCM) is a water free crystalline form of grape sugar, offering a purer, more stable, and easier-to-use alternative to the liquid Rectified Concentrated Must (RCM).