Macrowine 2021
IVES 9 IVES Conference Series 9 Characterization of commercial enological tannins and its effect on human saliva diffusion

Characterization of commercial enological tannins and its effect on human saliva diffusion

Abstract

Commercial oenological tannins (TECs) are widely used in the wine industry. TECs are rich in condensed tannins, hydrolyzable tannins or a mixture of both. Wine grapes are a important source of proanthocyanidins or condensed tannins while oak wood possess a high concentration of hydrolyzable tannins (Obreque-Slier et al., 2009). TECs contribute with the antioxidant capacity of wine, catalyze oxide-reduction reactions and participate in the removal of sulfur compounds and metals. One of the most important properties of TECs correspond to its contribution to the astringency (Zamora, 2003). Astringency, a sensation that is described as a puckering, rough, or drying mouth-feel, has been associated with interactions between some phenolic compounds (tannins) and salivary proteins (Bacon and Rhodes, 2000). A wide spectrum of enological tannins is now available on the market, classified mainly according to the enological properties. However, the tannins’ chemical nature is not always clearly defined. Furthermore, the effect of these on saliva is unknown. For that reason, the aim of this work was the chemical characterization of eleven commercial tannins sold for enological use. Likewise, we examined the effect of TECs on a physicochemical property of the salivary protein, namely, the mode of diffusion on cellulose membranes (Obreque-Slier et al., 2010). In this study, eleven enological tannins were characterized by classification into three groups according HPLC-DAD chromatography and spectroscopic analysis: enological products composed of proanthocyanidins, hydrolyzable, and the mixture of both types of tannins. Within each group, tannin composition varied greatly, mainly defined by the botanical origin of each commercial product. Similarly, when saliva was mixed with aliquots of increasing concentrations of TECs, we observed a progressive decrease in the blue-stained background of the distribution area of the salivary protein. The intensity of this restriction was in close relationship with the type of TECs. Finally, it was observed that certain TECs do not showed a effect on saliva diffusion on cellulose membranes.

References 1.- Bacon J., Rhodes M. 2000. Binding affinity of hydrolyzable tannins to parotid saliva and to proline-rich proteins derived from it. J Agric Food Chem 48, 838-843. 2.- Obreque-Slier E., Peña-Neira A., López-Solís R., Ramírez-Escudero C., Zamora-Marín F. 2009. Phenolic characterization of commercial enological tannins. Eur Food Res Technol 229, 859-866. 3.- Obreque-Slier E., Peña-Neira A., López-Solís, R. 2010. Quantitative determination of interactions between a tannin and a model protein using diffusion and precipitation assays on cellulose membranes. J Agric Food Chem 58, 8375-8379. 4.- Zamora, F. 2003. Elaboración y crianza del vino tinto: Aspectos científicos y prácticos. Madrid, España. Ediciones Mundi Prensa. 225p. Acknowledgments This study was supported by grant Fondecyt-Chile 1150240.

Publication date: May 17, 2024

Issue: Macrowine 2016

Type: Poster

Authors

Elías Obreque Slier*, Álvaro Peña-Neira, Dante Munoz, Gina Vazallo, Marcela Medel, Remigio López

*Universidad de Chile

Contact the author

Tags

IVES Conference Series | Macrowine | Macrowine 2016

Citation

Related articles…

Oenological features of Sangiovese wine from vinification of whole grape berries

The present study was performed in a traditional winery located in the viticultural area of Brunello di Montalcino, Siena, Italy, in the vintage 2015. Actually, in this winery Sangiovese grape musts are fermented in large oak barrels by a single strain of Saccharomyces cerevisiae previously isolated in the same winery. Pumping over operations are carried out once or twice a day until the end of alcoholic fermentations. The aim of this work was to investigate on the oenological properties of Sangiovese wine produced with the traditional winemaking process adopted by the winery under study obtained from the fermentation of whole berries compared to that from crushed grape must. In particular, two lots of 65q of Sangiovese grapes from the same 3ha vineyard were vinified in 150hL oak barrels.

An excessive leaf-fruit ratio reduces the yeast assimilable nitrogen in the must

Yeast assimilable nitrogen (YAN) in the grape must is a key variable for wine quality as a source of aroma precursors. In a situation of YAN deficiency, a foliar urea application upon the vine at veraison enhances YAN concentration and facilitates must fermentation. In 2013, Agroscope investigated the impact of leaf-fruit ratio on the nitrogen (N) assimilation and partitioning in grapevine Vitis vinifera cv. Chasselas following foliar-urea application with the aim of improving its efficiency on the YAN concentration.

Correlations between N,S,O-heterocycle levels and age of Champagne base wines

Champagne regulation allows winegrowers to stock small amounts of still wines in order to compensate vintages’ quality shifts mainly due to climate variations. According to their technical requirements and house style some Champagne producers (commonly named “Champagne houses”) use these stored wines in the blend in order to introduce an element of complexity. These wines possess the particularity of being aged on fine lees in thermo-regulated stainless steel tanks. The Champagne house of Veuve Clicquot Ponsardin has several wines stored this way.

Improving the phenolic composition of cv tempranillo wines by blending grapes of different ripening state

The aim of this work was to reduce the alcohol content of Tempranillo wine. Tempranillo wines were produced by grapes harvested at different ripening dates (August 11 which was 21 oBrix and September 28 with 25 oBrix). At the second date, the Tempranillo wines were elaborated as follows: grapes were destemmed, crushed and collected into 50 L stainless-steel vats. Before preferementative maceration in cold, 50 % (M1) and 70 % (M2) of the must have been replaced by the same percentage of must from the first harvest. In addition, a control wine (C) was performed with only grapes from the second harvest.

Evaluating South African Chenin blanc wine styles using an LC-MS screening method

Sorting Chenin blanc is one of the most important white wine cultivars in South Africa. It has received a lot of attention and accolades in the past years and more research than ever is dedicated to this versatile cultivar. According to the Chenin blanc association of South Africa, there are three recognized dry wine styles, Fresh and Fruity (FF), Rich and Ripe Unwooded
(RRU), and Rich and Ripe Wooded (RRW). They are traditionally established with the aid of expert sensory evaluation, but the cost and the (subjective) human factor are aspects to be taken into account. A more objective and possibly robust way of assessing and attributing these styles can be the use of chemical analysis.