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…

Metabolomics of grape polyphenols as a consequence of post-harvest drying: on-plant dehydration vs warehouse withering

A method of suspect screening analysis to study grape metabolomics, was developed [1]. By performing ultra-high performance liquid chromatography (UHPLC) – high-resolution mass spectrometry (HRMS) analysis of the grape extract, averaging 320-450 putative grape compounds are identified which include mainly polyphenols. Identification of metabolites is performed by a new HRMS-database of putative grape and wine compounds expressly constructed (GrapeMetabolomics) which currently includes around 1,100 entries.

How do different oak treatment affect the sensory composition of Chenin blanc wines over time?

Wooden barrels have been the preferred method for oak maturation for wines, but the use of alternative oak products, such as staves and oak chips have increased in South Africa due to lower production costs. This study investigated the effect of different oak products used during fermentation and ageing on the sensory profile, degree of liking and perceived quality of a South African Chenin blanc wine. The different wine treatments included an unoaked tank control wine, wines matured in 5th fill barrels, wines matured in new barrels from three different cooperages, and wines matured in 5th fill barrels with stave inserts from two different cooperages.

Correlations between N,S,O-heterocycle levels and age of Champagne base wines

Champagne regulation allows winegrowers to stock small amounts of still wines in order to compensate vintages’ quality shifts mainly due to climate variations. According to their technical requirements and house style some Champagne producers (commonly named “Champagne houses”) use these stored wines in the blend in order to introduce an element of complexity. These wines possess the particularity of being aged on fine lees in thermo-regulated stainless steel tanks. The Champagne house of Veuve Clicquot Ponsardin has several wines stored this way.

Fingerprinting the origin of rosé wines with a new high throughput polyphenomics method

Wine is a widely consumed alcoholic beverage with a high commercial value. More specifically, the worldwide consumption of rosé wine has increased by 20% since 2002[1]. But because of its high commercial value, it can become a subject of fraud, and authenticity control is necessarily required. More than one hundred polyphenols have been recently quantified in various rosé wines [2]. They are key components defining color, taste and quality of wines. Their amount and composition depend on many different factors such as grape variety, winemaking and age of the wine. In this study, the influence of geographic origin of some rosé French wines was investigated. An original and very fast UPLC-QTOF-MS method was developed and used to predict the geographic origin authenticity of rosé wines.

Impact of drought stress on concentration and composition of wine proteins in Riesling

Protein haze in white wines is a major technological and economic problem of the wine industry. Field tests were carried out in steep slope vineyards planted with Riesling grapes over 3 dry growing seasons to study the effect of drought stress on the concentration of proteins in the resulting wines. Plots suffering from drought stress were compared with surrounding drip irrigated plots. Riesling grapes were processed into wines by conventional procedures. Protein amounts of the isolated wine colloids of the stressed samples were always higher than those of the watered samples(mean watered 13.8 ± 0.44, mean stressed 17.4 ± 0.40 g 100 g-1). As a consequence, higher bentonite doses were needed to achieve protein haze stability of the drought stressed treatments.