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…

Effect of different foliar nitrogen applications on the must amino acids and glutathione composition in Cabernet Sauvignon vineyard

Cabernet Sauvignon is one of the most important winegrape varieties in Chile. However, temperature raise and decreased rainfall due to climate change can lead to grape quality decrease in certain areas. Amino acids are essential as nitrogen source for yeast but also directly affect grape quality serving as precursors of certain volatile compounds that enhance the wine bouquet. Besides, glutathione is an important tripeptide acting as antioxidant, preventing the appearance of browning pigments in must and exerts a protective effect in volatile compounds.

Read More

Influence of wood chips addition during alcoholic fermentation on wine phenolic composition

This study investigates the effect of wood chips addition during the alcoholic fermentation on the phenolic
composition of the produced wines. A series of wood chips, originating from American, French, Slavonia
oak and Acacia were added at the beginning of wine alcoholic fermentation. Besides, a mixture consisting
of 50% French and 50% Americal oak chips were added during the experimentation. The wine samples
were analyzed one month after the end of malolactic fermentation, examining various chemical
parameters such as total anthocyanins, total phenolic content, tannins combined with protein (BSA) and
ellagitannin content.

Read More

Micro-meteorological, compositional and transcriptional study of corvina grape color during ripening

Grape anthocyanin content and composition could affect the quality and the production strategies of red wines. Differences in the pigment composition modify the color properties in terms of hue, extractability and stability. Thus, for the production of a highly qualitative wine such as “Amarone”, variations in the pigment composition are not negligible. The aim of this work was the investigation of the anthocyanin profile changes during ripening in Corvina grapes, the main cultivar for the “Amarone” production. The experiment took place in 2015, in two vineyards located in Valpollicella (Italy).

Read More

The effect of cropload on the volatile aroma characteristics of ‘Beihong’ and ‘Beimei’ red wine

Beihong and Beimei were bred as winemaking cultivars released by Institute of Botany, the Chinese Academy of Sciences in 2008. The cultivars are selected from the population of ‘Muscat Hamburg’ (Vitis vinifera) ×V. amurensis. They are extended to most provinces in North of China because they have strong resistance to cold and disease and need not be buried in soil in winter. To better understand the effect of cropload on volatile compounds during wine-making, we surveyed volatiles composition and content of different cropload level in 3-years-old ‘Beihong’ and ‘Beimei’ vines which planted in east foot of Helan mountain of Ningxia (EHN).

Read More

Bentonite fining in cold wines: prediction tests, reduced efficiency and possibilities to avoid additional fining treatments

Bentonite fining is widely used to prevent protein haze in white wines. Most wineries use laboratory-scale fining trials to define the appropriate amount of bentonite to be used in the cellar. Those pre-tests need to mimic as much as possible the industrial scale fining procedure to determine the exact amount of bentonite necessary for protein stability. Nevertheless it is frequent that, after fining with the recommended amount of bentonite, wines appear still unstable and need an additional fining treatment. It remains a major challenge to understand why the same wine, fined with the same dosage of the same bentonite, achieves stability in the lab, but not in the cellar.

Read More