Macrowine 2021
IVES 9 IVES Conference Series 9 Characterization of Glycosidically Bound Aroma Compounds of País cv. grapes of different Chilean zones

Characterization of Glycosidically Bound Aroma Compounds of País cv. grapes of different Chilean zones

Abstract

País grape has been estimated to arrive to Chile almost 500 years ago, being the first strain grown in this country. Traditionally, this grape has been used to mix with other varieties, to produce poor quality wines, but today is beginning to be used in the production of high quality wines. However, very little is known about the chemical characteristics of this variety. The aroma is one of the most important quality attributes of wine. Volatile compounds of this beverage may come from the grape (varietal aromas), from the fermentation process, from the ageing. The aromatic compounds are found in the grape in two forms: as free volatile compounds and as non-volatile compounds. The last ones, are aroma precursors present mainly as glycoconjugates formed by a sugar and an aglycone. They are potential natural sources of aroma because the hydrolysis of the bonds between the sugar and the aglycone, for example during the ripening of the fruit or the fermentation by the yeast, turns this molecule into an aromatic compound. These non-volatile compounds have been extensively studied in grapes due to their importance in the wine aroma. The aims of this work were to study glycosidic aroma precursors of País grapes from three Chilean zones from the Maule Region and determine where these compounds are mainly located in the grape (pulp or skin). For this purpose, grapes from three zones, Hualañé, Cauquenes and Itata were harvested post veraison and analyzed. The glycosides were extracted by passing the samples through the solid-phase extraction medium, and the aglycone was released by acid hydrolysis as described by Loscos et al. (2009). The extract was analyzed by gas chromatography mass spectrometry. The results showed that the principal groups of aroma precursors in País grapes were alcohols, aldehydes and terpenes. Among them, the most abundant was 2-ethyl-1-hexanol followed by benzaldehyde. In reference with the location of the aromatic precursors, the biggest amounts were found in the skins of all the samples. Among all the chemical groups, terpenes accounted the biggest amount differences between the skin and the pulp.

Loscos, N.; Hernández-Orte, P.; Cacho, J.; Ferreira, V. Comparison of the suitability of different hydrolytic strategies to predict aroma potential of different grape varieties. J. Agric. Food Chem. 2009, 57, 2468-80.

Acknowledgements: This study was supported by FONDECYT N°11140275.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Cristina Ubeda*, Álvaro Peña-Neira, Raquel Callejón

*Universidad Autónoma de Chile

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Use of chitosan as a secondary antioxidant in juices and wines

Chitosan is a polysaccharide produced from the deacetylation of chitin extracted from crustaceous and fungi. In winemaking chitosan is mainly used in the clarification of grape juice and wine, stabilization of white wines, removal of metals and to prevent wine spoilage by undesired microorganisms. The addition of chitosan to model wine systems was able to retard browning, reduce levels of metallic ions (Fe and Cu) and to protect varietal thiols due to its antiradical activity1. The present experiment was planned in order to evaluate the use of chitosan as a secondary antioxidant at three different stages of Sauvignon blanc fermentation and winemaking. Sauvignon blanc juices from three different locations were obtained at a commercial winery in Marlborough, New Zealand. One lots of grapes was collected from a receival bin and pressed into juice with a water-bag press, and a further juice sample was collected from a commercial pressing operation. Chitosan (1 g/L, low molecular weight, 75 – 85% deacetylated) was added to the juice after pressing, after cold settling, after fermentation, or at all these stages. Controls without any chitosan additions were also prepared.
Read More

Characterization of various groups of pyranoanthocyanins in Merlot red wine

In red wines, anthocyanins evolve during the wine-making process and ageing. They react with other compounds (such as vinylphenols, acetaldehyde, pyruvic acid…) to form a stable family of compounds called pyranoanthocyanins. Furthermore, the oxidation process can modify the anthocyanic profile of a red wine. It is also interesting to evaluate the occurrence of the different subclasses of pyranoanthocyanins and to characterize their chemical properties. The first objective of this study is to evaluate the occurrence of the different groups of pyranoanthocyanins in an oxidised Merlot wine by a centrifugal partition chromatography strategy. The second goal is to evaluate their relative impact in red wines from Bordeaux region by measuring their concentrations.

Read More

Impact of some agronomic practices on grape skins anthocyanin content

Wine colour is the first quality characteristic to be assessed, especially regarding red wines. Anthocyanins are very well known to be the main responsible compounds for red wine colour. Red cultivars can synthesize and accumulate anthocyanins in berry skin to express their colour. However, anthocyanin accumulation is often influenced by a series of factors, such as genetic regulation, phytohormones, environmental conditions and viticultural management.

Read More

Merging fast sensory profiling with non-targeted GC-MS analysis for multifactorial experimental wine making

Wine aroma is influenced by several viticultural and oenological factors. In this study we used experimental wine making in a full factorial design to determine the impact of grapevine age, must turbidity, and yeast strain on the aroma of Vitis vinifera L. cv. Riesling wines. A recently developed, non-targeted SPME-GC-MS fingerprinting approach for wine volatiles was used. This approach includes the segmentation and mathematical transformation of chromatograms in combination with Parallel Factor Analysis (PARAFAC) and subsequent deconvolution of important chromatogram segments.

Read More

Characterizing the effects of nitrogen on grapevines with different scion/rootstock combinations: agronomic, metabolomic and transcriptomic approaches

Most vineyards are grafted and include a variety (Vitis vinifera) grafted over a wild Vitis rootstock (hybrids of V. berlandieri, riparia and rupestris). Grape berry quality at harvest depends on a subtle balance between acidity and the concentrations of sugars, polyphenols and precursors of aroma compounds. The mechanisms controlling the balance of sugars/acids/polyphenols are influenced by the abiotic environment, in particular nitrogen supply, and interact with the genotypes of both the scion variety and the rootstock. Previous work suggests that some of the effects of water stress are in fact linked to a nitrogen deficiency driven indirectly by the reduction of water absorption.

Read More