OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 OENO IVAS 9 OENO IVAS 2019 9 Analysis and composition of grapes, wines, wine spirits 9 Key odorants responsible for the sensory spaces defining the different aroma potentials of Grenache and Tempranillo grapes

Key odorants responsible for the sensory spaces defining the different aroma potentials of Grenache and Tempranillo grapes

Abstract

There are yet many gaps in our knowledge about the aroma potential of winemaking grapes and its measurement. Trying to bring some light into this question, a new general strategy based on the accelerated hydrolysis of reconstituted phenolic and aromatic fractions (PAFs) extracted from grapes has been developed. In this paper, we present results obtained by applying such PAFs strategy to the study of 33 different lots of grapes from grenache and Tempranillo from different areas of Spain and different qualities.

Grapes were first crushed and macerated in the presence of ethanol to avoid fermentation. The ethanolic must was pressed and filtered, then, an aliquot was centrifuged, dealcoholized and extracted in a C18 cartridge. Phenols and aroma precursors, PAFs, were eluted with ethanol. This ethanolic fraction was then reconstituted with water and tartaric acid to make a reconstituted wine model (r-PAF; 13.3% ethanol, pH 3.5). Aroma was developed by storing the r-PAFs in complete anoxia at 75ºC for 24h. The 33 ar-PAFs were subjected to different sensory analyses. First, a sorting task to define sensory categories and to select the most representative samples, which were characterized by flash profiling and by gas chromatography-olfactometry (GC-O).

Samples developed strong aroma nuances over a background of vegetal and dry fruit odors and were classified into six different sensory categories: 1) citrus & floral; 2) dried fruit & floral; 3) wood, toast & red fruit; 4) red fruit, black fruit & dried fruit; 5) vegetable & dried fruit; and vi) vegetable. Vegetal notes were attributed to aroma compounds derived from lipid oxidation (Z-3-hexenal, Z-2-nonenal, E-2-nonenal and 1-octen- 3-one), while the dry fruit background was attributed to β-damascenone and to massoia lactone. Citrus notes were associated to the surprising presence of 3-mercaptohexanol, whose origin has been exclusively associated to fermentation. Woody and toasty character were attributed to guaiacol and 4-allyl-2-methoxyphenol while furaneol and an unknown ester-like odorant could be linked to red fruit notes. Samples from Grenache were more often classified as floral, citrus and dry fruit, while samples from tempranillo were more often classified as woody, toasty, red fruit and vegetal.

Overall, the procedure provides a new insight into the aroma potential of winemaking grapes, which should be helpful in understanding and managing grape quality.

Acknowledgments

Work funded by the Spanish MCIU AGL2017-87373-C3-1R. Y.A. and LAAE acknowledge the Diputación General de Aragón for a predoctoral fellowship, as well as the European Social Fund.

DOI:

Publication date: June 11, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Yohanna Alegre, SaraFerrero-del-Teso, María-Pilar Sáenz-Navajas, Purificación Fernández-Zurbano, Purificación Hernandez-Orte, Vicente Ferreira

Laboratorio de Análisis del Aroma y Enología (LAAE), Department of Analytical Chemistry, Universidad de Zaragoza, Instituto Agroalimentario de Aragón (IA2) (UNIZAR-CITA), Associated unit to Instituto de las Ciencias de la Vid y el Vino (ICVV) (UR-CSIC-GR)

Contact the author

Keywords

Phenolic and aromatic fractions (PAFs), accelerated hydrolysis, sensory analysis ,GC-O 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.