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


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


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

*Universidad de Chile

Contact the author


IVES Conference Series | Macrowine | Macrowine 2016


Related articles…

A combination of biotechnology tools and coopers elements for an alternative the addition of SO2 at the end of the malolactic fermentation in red wines or at the “mutage” for the “liquoreux” wines

In red wines the post-MLF SO2 addition is an essential event. It is also the case for the “mutage” during the elaboration of the “liquoreux”. At these moments SO2 plays an antimicrobial action and an antioxidant effect. But at current pH of wines, ensuring a powerful molecular SO2 has become very difficult. Recent work on Brettanomyces strains have also shown that some strains are resistant up to 1.2 mg / L of molecular SO2. It’s also the case of the some Saccharomuces or Zygosaccharomyces strains suitable to re-ferment “liquoreux” wines after the “mutage”.

Effect of nanofiltration on the chemical composition and wine quality

In Enology the conventional processes of filtration for clarification and stabilization are giving place to alternative membrane processes, including nanofiltration (NF). Furthermore, the increased alcohol content in wines recorded in recent years became an important issue for all the main wine producing countries. Among techniques available to the wine industry to reduce the ethanol content, NF is certainly one of the newest. This study is focused on the evaluation of NF influence on wine physical-chemical composition, including mineral content, which in accordance to our best knowledge is a novelty.

Characterization of free and glycosidically bound simple phenols in hybrid grape varieties using liquid chromatography coupled to high resolution mass (q-orbitrap)

Vitis vinifera is one of the most diffused grapevines over the word and it is the raw material for high quality wines production. The availability of more resistant interspecific hybrid vine varieties, developed from crosses between Vitis vinifera and other Vitis species, has generating much interest, also due to the low environmental effect of production. However, hybrid grape wine composition and varietal differences between interspecific hybrids are not well defined. Different studies revealed that wine consumption has health effects due to its high content of antioxidants, as phenolic compounds. In particular, simple phenols are appreciated not only for their physiological health benefits, including antioxidant, anti-inflammatory and cardioprotective effects, but also because they affect wines organoleptic profile and have a significant role in defining their nutritional characteristics.

Comprehensive exploration of wine aroma-related compounds as promoted by alternative vinification procedures in case of Zelen (Vitis vinifera L.) grapes processing

Not only vintner’s decisions in the vineyard, but also winemaker’s choices of technology approaches in the cellar play a significant role in the final wine style and quality. Whereas traditional technologies within chosen terroir are quite well explored and thus somehow predictable, there is no proper knowledge available on possible outcomes in case of implementing novel, alternative winemaking strategies. To reveal their effects on wine aroma compounds and sensory characteristics, two alternative strategies
(cryoextraction or addition of whole grape berries during last stages of fermentation) were compared to classical Vipava valley winemaking approach as normally used for an autochthonous variety Zelen. After separate vinification and bottling, all the experimental wines were subjected to semiquantitative metabolic profiling of volatile compounds (VOCs) by means of GC/MS and were then also sensorialy evaluated by pre-trained panel.

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).