 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

Monitoring water deficit in vineyards by means of Red and Infrared measurements

Vineyard water availability is one of the most important variables both in plant’s production and wine quality, once it regulates several processes, among which the stomata activity. To avoid water deficit, wine producers introduced artificial irrigation in their vineyard, using a semi-empirical process to calculate water amount.

Zoning, environment, and landscape: historic and perspective

Dans une approche globale, nous proposons la définition suivante du zonage : “représentation cartographique associée à une sectorisation du territoire en zones unitaires homogènes à partir de facteurs discriminants établis sur la base d’indicateurs quantifiables et d’avis d’experts”. La première application de cette méthode a porté sur la caractérisation du terroir en liaison avec les aspects qualitatifs des vins. Il est également possible d’envisager d’appliquer cette démarche dans les stratégies environnementales et paysagères liées aux approches territoriales et aux pratiques viticoles. Cette méthode peut servir de base dans la mise en œuvre des outils financiers associés aux mesures environnementales (CTE, aides spécifiques).

Behaviour of two training systems for mechanical pruning combined with different nitrogen fertilizations on cv. Colombard

Today winegrowers involved in mechanical winter pruning are applying this viticultural technique on two main training systems, the free cordon, appearing to be the more efficient, and the trellised vertical shoot positioning (VSP) system. The main reasons for maintaining the trellis are generally due to common habits in vineyard management, risk of wind damage for the shoots, or risk of decrease in photosynthesis potential. The aim of the study was to assess the effects of the two training systems on vine. In addition, different nitrogen fertilization levels were applied on the two systems to evaluate the best combination to achieve yield and grape quality.

Ethyl esters interact with the major wine Thaumatin Like Protein VVTL1

The interactions among aromatic compounds and proteins is an important issue for the quality of foods and beverages. In wine, the loss of flavor after vinification is associated to bentonite treatment and this effect can be the result of the removal of aroma compounds which are bound wine proteins. This phenomenon was recently demonstrated for long chain fatty acids and their ethyl esters (1). Since these latter compounds are spectroscopically silent, their association with proteins is not easy to measure.

The dynamics of δ13C and δ18O in musts during berries development

Aim: Many processes or reactions that occur in plants involved isotopic discrimination. Water availability, for example, affects the isotopic ratio of carbon (δ13C) and oxygen (δ18O). In viticulture, δ13C is used in experiments related to water relations and irrigation in vineyards. δ18O is used much less but it could be a good complement to δ13C. The aim of this study was to generate knowledge on how these isotopic ratios, measured in musts, could help to better understand the water behavior of grape varieties.