 IVES 9 IVES Conference Series 9 Relationship between chemical parameters of tannins and in-mouth attributes of grape phenolic fractions

Relationship between chemical parameters of tannins and in-mouth attributes of grape phenolic fractions

Abstract

AIM: Establish relationships between taste and mouthfeel properties of grapes and tannin-related chemical parameters.

METHODS: Tempranillo Tinto and Garnacha Tinta grapes were harvested from distinct blocks in different dates; each sample collection date was separated by one week. Grapes were destemmed and macerated in 15% of ethanol for one week. The polyphenolic fraction (PF) of samples was submitted to solid phase extraction on C18 cartridges and recovered with ethanol. PFs were reconstituted in wine model and their taste and mouthfeel properties were characterised by rate-K-attributes methodology. In parallel, concentration (TC) and activity (TAc) of tannins as well as the concentration of tannins linked to anthocyanins (T-A) were determined using HPLC-UV–VIS.

RESULTS: Garnacha PFs show significatively lower values for TAc, TC and the concentration of polymeric pigments (T-A) than Tempranillo PFs. On the one hand, for the Garnacha PFs, TAc and TC present significant and positive correlations with the three dry-related terms evaluated (i.e.: “dry”, “dry on the tongue side” and “dry palate”). Besides, TC also shows negative correlations with “silky” and “watery” atributes and the concentration of polymeric pigments presents a positive correlation with the overall dry-related term: “dry” and a negative relationship with “fleshy”, “silky” and “gummy”. On the other hand, Tempranillo PFs do not present significant sensochemical correlations, which could be attributed to the fact that the chemical parameters of the PFs evaluated present a small variability inducing none significant sensory differences.

CONCLUSIONS:

The presented approach enables to have a representative pool of phenolic fractions of grapes. Significant correlations between mouthfeel terms such as “dry”, “silky”, “watery”, “fleshy”, “silky” and “gummy” and the chemical parameters measured are observed.

DOI:

Publication date: September 22, 2021

Issue: Macrowine 2021

Type: Article

Authors

Sara, Ferrero-Del-Teso , María-Pilar, SAENZ-NAVAJAS, Vicente, FERREIRA, FERNANDEZ-ZURBANO,

Institute of Grapevine and Wine Sciences (UR-CSIC-GR). La Rioja, Spain. University of Zaragoza, IA2, Spain. Purificación,

Contact the author

Keywords

mouthfeel, tannin activity, tannin concentration

Citation

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.