 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

NEW METHOD FOR THE QUANTIFICATION OF CONDENSED TANNINS AND OTHER WINE PHENOLIC COMPOUNDS USING THE AUTOMATED BIOSYSTEMS SPICA ANALIZER

Wine phenolic compounds are important secondary metabolites in enology due to their antioxidant and nutraceutical properties, and their role in the development of color, taste, and protection of wine from oxidation and spoilage. Tannins are valuable phenolic compounds that contribute significantly to these wine properties, especially in mouthfeel characteristics; however, tannin determination remains a significant challenge, with manual and time-consuming methods or complex methodologies. The purpose of this study is to propose a novel method for quantifying condensed tannins in finished wine products.

Effect of Quercus Alba oak barrels from different forests on the polyphenolic composition of Tempranillo red wines

The species and origin used for red wine oak aging determines the physiological composition of the wood and thus the finished wines. In America, oak is grown primarily in the states of Virginia, Missouri, Kentucky, Oregon, Ohio, Minnesota, Wisconsin and California. The aim of this study was to analyze how the choice of barrels made with Quercus Alba oak from different geographic areas of the United States (Missouri, Kentucky, Ohio and Pennsylvania) influences the polyphenolic composition of Tempranillo red wines.

Obtaining new varieties derived from Monastrell for the preparation of low alcoholic wines

The main challenge faced by viticulture is to improve the quality of the wines, adapting them to the new consumer demands that demand wines with lower alcohol content and greater freshness. In the last 30 years, a clear modification has been observed in the composition of the grape due to climate change

The moment of preharvest elicitor application influence its final effect on winegrapes quality

Phenolic compounds are secondary metabolites of grapes. Plants produce a wide variety of this type of metabolites through diverse biosynthesis pathways and their production is sometimes a response to external stimuli, either environmental or biotic stresses. Some of them may act as chemical defenses against pathogens or herbivores and their synthesis is increased when the attack exists. However, it is remarkable that the synthesis of these interesting compounds can be activated even when the stimulus is not present, with the use of elicitors. These are substances that when applied exogenously trigger the biosynthetic pathways conducting to the synthesis of these defense compounds.

Chemical profiling and sensory analysis of wines from resistant hybrid grape cultivars vs conventional wines

Recently, there has been a shift toward sustainable wine production, according to EU policy (F2F and Green Deal), to reduce pesticide usage, improve workplace health and safety, and prevent the impacts of climate change. These trends have gained the interest of consumers and winemakers. The cultivation of disease resistant hybrid grape cultivars (DRHGC), known as ‘PIWI’ grapes can help with these objectives [1]. This study aimed to profile white and red wines produced from DRHGC in South Tyrol (Italy). Wines produced from DRHGCs were compared with conventional wines produced by the same wineries. The measured parameters were residual sugars, organic acids, alcohol content, pigments and other phenolics by LC-QqQ/MS, colorimetric indexes (CIELab); and volatile profiles (HS-SPME-GCxGC-ToF/MS [2]).