 IVES 9 IVES Conference Series 9 A new approach for sensory characterization of grape. Relationship with chemical composition

A new approach for sensory characterization of grape. Relationship with chemical composition

Abstract

AIM: Characterize taste and mouthfeel properties of grapes elicited by the phenolic fraction (PF) of grape berries and establish relationships with chemical variables.

METHODS: As many as 31 diverse grape lots of Tempranillo Tinto and Garnacha Tinta from three different regions were harvested. Grapes were destemmed and macerated in 15% of ethanol for one week and extracts were submitted to solid phase extraction. The recovered polyphenolic fraction was reconstituted in wine model and characterized by a panel of 21 wine experts employing a list of 23 taste and mouthfeel-related attributes following a rate-k-attributes methodology.

RESULTS: Six significant attributes among the 31 samples differed based on ANOVA results: “dry”, “coarse”, “bitter”, “dry on tongue”, “sticky” and “watery”. PCA with VARIMAX algorithm was calculated. Three main independent dimensions defining the sensory space of PFs were identified: D1, “dry on the tongue”; D2, “bitter/ sticky”; and D3: “coarse/dry”. Two out of the three dimensions could be satisfactory modeled by PLS-regression from chemical parameters. Tannin activity and tannin concentration along with mDP of tannins proved to be good predictors of perceived dryness. Flavonols have a good prediction power for “bitter” attribute and the “sticky/bitter” dimension. In addition, the low molecular weight anthocyanins seem to be involved in the formation of the “dry” attribute, whereas large polymeric pigments in the “sticky” attribute and the “sticky/bitter” dimension.

CONCLUSIONS:

This study has increased our knowledge about some of the chemical drivers of grape sensory properties and presents a powerful tool for the wine industry to assess grape quality.

DOI:

Publication date: September 22, 2021

Issue: Macrowine 2021

Type: Article

Authors

Maria-Pilar Saenz-Navajas , Logroño, Alejandro, Suárez, Chelo, Ferreira, Panagiotis, Arapitsas, Daniele, Perenzoni, Fulvio, Mattivi, Vicente, Ferreira,

Instituto De Ciencias De La Vid Y Del Vino (Ur-Csic-Gr). Department Of Enology, La Rioja, Spain, Universidad De Zaragoza, Iuma, Spain. Fondazione Edmund Mach, Italy. Universidad De Zaragoza, Ia2, Spain. Purificación, Fernandez-Zurbano, Instituto De Ciencias De La Vid Y Del Vino (Ur-Csic-Gr). La Rioja, Spain.

Contact the author

Keywords

pls, phenolic fraction, grape quality, mouthfeel, taste

Citation

Wine odors: chemicals, physicochemical and perceptive processes involved in their perception

The odors of wines are diverse, complex and dynamic and much research has been devoted to the understanding of their chemical bases. However, while the “basic” chemical part of the problem, namely the identity of the chemicals responsible for the different odor nuances, was satisfactorily solved years ago, there are some relevant questions precluding a clear understanding. These questions are related to the physicochemical interactions determining the effective volatilities of the odorants and, particularly, to the perceptual interactions between different odor molecules affecting in different ways to the final sensory outputs.

Techniques to study graft union formation in grapevine

Grapevines are grown grafted in most viticultural regions. Grapevine rootstocks are either hybrids or pure species of different American Vitis spp. (particularly V. berlandieri, V. rupestris and V. riparia), which were primarily used to provide root resistance to the insect pest Phylloxera. In addition to Phylloxera resistance, grapevine rootstocks were also selected in relation their resistance to various abiotic stress conditions. Future rootstocks should have the potential to adapt viticulture to climate change without changing the characteristics of the harvested product. However, high grafting success rates are an essential prerequisite to be able to use them with all the varieties. The objective of this work is to develop quantitative techniques to characterize graft union formation in grapevine.

Recent observations in wine oxidation

The chemistry of wine oxidation is captured in the reactions between the oxidation products, mostly reactive electrophiles, with other wine constituents. An understanding of both components and their reactions can lead to ideas and techniques to control and mitigate or enhance these reactions to allow for the desired development of the wine. Current investigations are yielding much useful information about oxidation reactions in wine.

Organic mulches slightly influence wine phenolic composition and sensorial properties

Grapevines have traditionally been grown in semi-arid areas, but viticulture is now compromised by climate change. Therefore, it is necessary to implement environmentally friendly viticulture practices to adapt grapevines to current climatic conditions. In this context, organic mulches offer many benefits, such as reduced soil erosion and increased organic matter, soil water content and crop productivity. However, these practices must not compromise grape and wine quality. Therefore, the objective of this study was to evaluate the effect on wine physicochemical and phenolic composition and sensorial properties of different soil management practices on the vine row. Over four years, five soil treatments were examined in two different vineyards.

Effect of climate and soil on phenology and ripening of Vitis vinifera cv Touriga acional in the Dão region

“Terroir” has been acknowledged as an important factor in wine quality
and style. It can be defined as an interaction between climate, soil, vine (cultivar, rootstock) and human
factors such as viticultural and enological techniques. Soil and climate are the two components of the “Terroir” with an important role on the vine development and berries ripening. The present study is focused on the effects of the weather conditions and the soil characteristics on the phenological and berries ripening dynamics of the “Touriga Nacional” in Dão region.