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…

Moscatel vine-shoot extracts as grapevine biostimulant to increase the varietal aroma of Airén wines

There is a growing interest in the exploitation of vine-shoots waste, since they are often left or burned. Sánchez-Gómez et al. [1] have shown that vines-shoots aqueous extracts have significant contents of bioactive compounds, among which several polyphenols and volatiles are highlighted. Recent studied had demonstrated that the chemical composition of vine-shoots is enhanced when vine-shoots are toasted
[2,3]. The application of vegetable products in the vineyards has led to significant changes towards a more “Sustainable Viticulture”. An innovative foliar application for Airén vine-shoot extracts have been carried out to the vineyard. It has been shown that they act as grape biostimulants, improving certain wine quality characteristics [4].

How small amounts of oxygen introduced during bottling and storage can influence the metabolic fingerprint and SO2 content of white wines

The impact of minute amounts of headspace oxygen on the post-bottling development of wine is generally considered to be very important, since oxygen, packaging and storage conditions can either damage or improve wine quality. This is reflected in the generalised use of inert bottling lines, where the headspace between the white wine and the stopper is filled with an inert gas. This experiment aimed to address some open questions about the chemistry of the interaction between wine and oxygen, crucial for decisions regarding optimal closure. While it is known that similar amounts of oxygen affect different wines to a variable extent, our knowledge of chemistry is not sufficient to construct a predictive method.

Fingerprinting the origin of rosé wines with a new high throughput polyphenomics method

Wine is a widely consumed alcoholic beverage with a high commercial value. More specifically, the worldwide consumption of rosé wine has increased by 20% since 2002[1]. But because of its high commercial value, it can become a subject of fraud, and authenticity control is necessarily required. More than one hundred polyphenols have been recently quantified in various rosé wines [2]. They are key components defining color, taste and quality of wines. Their amount and composition depend on many different factors such as grape variety, winemaking and age of the wine. In this study, the influence of geographic origin of some rosé French wines was investigated. An original and very fast UPLC-QTOF-MS method was developed and used to predict the geographic origin authenticity of rosé wines.

Microbial stabilization of wines using innovative coiled UV-C reactor process: impact on chemical and organoleptic proprieties

For several years, numerous studies aimed at limiting the use of SO2 in wines (thermal treatments, pulsed electric fields, microwaves …). Processes must be able to preserve the organoleptic qualities of wines with low energy consumption. In this context, ultraviolet radiations (UV-C), at 254 nm, are well known for their germicidal proprieties. In order to inactivate microorganisms in grape juice and wine without affecting the quality of the product, efficiency of UV-C treatment process should be optimized.

Study of the volatil profile of minority white varieties

The genetic material preservation is a priority issue in winemaking research. The recovery of minority grape varieties can control the genetic erosion, contributing also to preserve wine typical characteristics. In D.O.Ca. Rioja (Spain) the number of grown white varieties has been very limited, representing Viura the 91% of the cultivated white grape area in 2005, while the others, Garnacha Blanca and Malvasía riojana, hardly were grown. For this reason, a recovery and characterization study of plant material was carried out in this region. In 2008, the results obtained allowed the authorization of three minority white varieties: Tempranillo Blanco, Maturana Blanca and Turruntés.