OENO IVAS 2019 banner
IVES 9 IVES Conference Series 9 Sensory evaluation of grape berries: predictive power for sensory properties of Sauvignon blanc, Riesling and Pinot noir wines

Sensory evaluation of grape berries: predictive power for sensory properties of Sauvignon blanc, Riesling and Pinot noir wines

Abstract

Sensory analysis of grape berries is a common tool to evaluate the degree of grape maturation and to make sound picking decisions. However, most of it is based on anecdotal knowledge and scientific studies relating berry and wine properties are rather limited [1]. 

Ten grapes of each variety (Sauvignon Blanc, Riesling, Pinot Noir) were picked weekly. Berries were dissected manually to obtain berries with intact peduncles. Using sucrose solutions of different densities, berries were separated into three density fractions of 1.070, 1.080, and 1.090. Three individual berries were assessed of each density group on each picking date. White and red wines were made from grapes picked concurrently with berry samples and were fermented in duplicates [2]. 

For Sauvignon Blanc 13 out of 21 visual, haptic, odor and taste attributes varied significantly among the three picking dates. Firmness and yellow color of the berries and brown color of the seeds and bitter berry skins yielded the largest F-ratios. Green notes in pulp and skin decreased during ripening. Variation of grape berry density yielded 14 significant attributes, including sweet and sour taste as well as fruity perception [2]. 

In a PCA the first PC was governed by ripe versus unripe attributes, while PC2 was dominated by presence versus absence of green odors in pulp and skin. Sensory evaluation revealed better grouping by density than grouping by picking date. 

Correlating berry and wine sensory brown seeds and sweet pulp correlated with increased peach and passionfruit notes in the wines. However, no correlation was found for green notes depicted in berries and green bell pepper nuances in the wines or fruity aspects in the berry and passion fruit / peach intensities in the wine. 

In conclusion, berry sensory yields a good characterization of the ripening process as well as technological grape properties, but is rather limited in the prediction of wine sensory properties. 

[1] Winter, E, Whiting, J., Rousseau, J. Berry Sensory Assessment, 2004, Winetitles, Adelaide, Australia 
[2] Nopora, J., Klink, S., Fischer, U. Reifeprüfung – Aussagekraft der Beerensensorik bei der Reifemessung, 2018, Der Deutsche Weinbau 17/18, pg. 26-30

DOI:

Publication date: June 19, 2020

Issue: OENO IVAS 2019

Type: Article

Authors

Ulrich Fischer, Julia Nopora

Rebschule Freytag, 67435 Lachen-Speyerdorf, Germany
Breitenweg 71, 67435 Neustadt an der Weinstraße, Germany

Contact the author

Keywords

Sensory evaluation, grape berry, grape maturity, wine 

Tags

IVES Conference Series | OENO IVAS 2019

Citation

Related articles…

Generation of radicals in wine by cavitation and study of their interaction with metals, phenols and carboxylic acids

High-power ultrasounds have been related to an accelerated aging of wines, an effect that has been associated to the formation of radical species caused by the cavitation phenomenon [1]. This phenomenon consists of the formation of bubbles in the liquid medium that, when they collapse, cause high-pressure hot spots and temperatures of up to 4800 k [2], notably increasing the reactivity in the medium.

Barrel-to-Barrel Variation of Color and Phenolic Composition in Barrel-Aged Red Wine

Tangible variation of sensory characteristics is often perceived in wine aged in similar barrels. This variation is mostly explained by differences in the wood chemical composition, and in the production of the barrels. Despite these facts, the literature concerning barrel-to-barrel variation and its effect on wine sensory and chemical characteristics is very scarce [1]. In this study, the barrel-to-barrel variation in barrel-aged wines was examined in respect of the most important phenolic compounds of oenological interest and chromatic characteristics, considering both the effects of the (individual) barrel and cooperage. A red wine was aged in 49 new medium-toasted oak (Quercus petraea) barrels, from four cooperages, for 12 months

The use of zirconia dioxide enclosed in a metallic cage for the stabilisation of Chardonnay white wine

White wines are commonly stabilised by removing the heat unstable proteins through adsorption by bentonite, an effective but inefficient wine processing step. Alternative absorbents are thus sought and zirconium dioxide (zirconia) is recognised as a promising candidate.

The use of Hanseniaspora vineae on the production of base sparkling wine

Non-Saccharomyces yeasts have been associated, for many years, with challenging alcoholic fermentation processes. However, during the last decade the use of non-Saccharomyces yeasts in wine production has become increasingly widespread due to the advantages they can offer in mixed inoculations with Saccharomyces cerevisiae (Sc). In this respect, Hanseniaspora vineae (Hv), in synergy with Saccharomyces spp, represents an interesting opportunity to impart a positive contribution to the aroma complexity of wines. In fact, it is a well-known producer of pleasant esters, such as 2-phenylethyl acetate. This study compares the performances of Hv (strain Hv-205) in sequential inoculation modality to Sc in three Chardonnay musts for base sparkling wine production. No significant differences were observed in basic chemical parameters between wines except for titratable acidity, with a significantly decrease (up to 1.5 g/L) in Hv processes due to malic acid degradation. The analysis of the aroma compounds revealed remarkable differences in concentration of volatile metabolites, among others up to 37-fold increase of 2-phenylethyl acetate. In contrast, lower concentration of its alcohol were detected, suggesting higher acetylation activity by Hv.

Il monitoraggio meteorologico come strumento per la gestione della variabilità climatica in Franciacorta

Nel 2007 è stata avviata una ricerca nell’areale di produzione del Franciacorta DOCG che ha riguardato un ampio numero di vigneti di Chardonnay con riferimento ai quali sono stati acquisite