Astringency sub‐qualities of red wines and the influence of wine–saliva aggregates

Abstract

Astringency is a sensory attribute, related to the quality and mouthfeel of red wines. However, the origin of astringency sub-qualities, such as the typical drying astringency found in immature grapes is still unknown. Astringency of red wines with similar tannin content but different astringency sub-qualities, from different harvest dates, is studied. Astringency was characterized in terms of friction coefficient, polyphenol content, sensory analysis and tannin/salivary-proteins aggregates characterization. A different evolution during ripening was found for both Cabernet Sauvignon and Carménère, and tannin-protein aggregates showed differences in size, shape and surface. The velvety sub-quality appears to be related with aggregates with low precipitation, and with specific surface characteristics as roundness and Feret diameter. Results from this work propose an effect of aggregates on sensory perception and opens the possibility to explore their effect on oral lubrication.

Wine astringency: more than just tannin–protein interactions

“…100,114 Considering these findings and the aforementioned aggregates differences, astringency intensity could be related to an extent to the number of aggregates 5,11,100 and astringency sub-quality could be related to the specific physical characteristic of the aggregates. 114 A study of Wang et al 126 used model wines to explore different tribology measurements and correlated saliva-wine properties to differentiate some astringency sub-qualities. Particularly, the data suggests that sub-qualities, such as pucker and drying are independent sub-qualities of astringency and that they can be differentiated using tribological approaches.…”

“…Cabernet Sauvignon presented big, flat and open structures whereas Carménère presented smaller, globular and compact structures. 114 These findings suggest that a difference on tannin composition rather than tannin concentration leads to the formation of different kind of aggregatesin number, size and texturethat might be perceived differently in mouth, and therefore, might elicit different astringency sub-qualities. 100,114 Considering these findings and the aforementioned aggregates differences, astringency intensity could be related to an extent to the number of aggregates 5,11,100 and astringency sub-quality could be related to the specific physical characteristic of the aggregates.…”

“…114 These findings suggest that a difference on tannin composition rather than tannin concentration leads to the formation of different kind of aggregatesin number, size and texturethat might be perceived differently in mouth, and therefore, might elicit different astringency sub-qualities. 100,114 Considering these findings and the aforementioned aggregates differences, astringency intensity could be related to an extent to the number of aggregates 5,11,100 and astringency sub-quality could be related to the specific physical characteristic of the aggregates. 114 A study of Wang et al 126 used model wines to explore different tribology measurements and correlated saliva-wine properties to differentiate some astringency sub-qualities.…”

“…Recent work using a model consisting of human saliva, mucosa pellicle and an oral cell line (HSC-3) to study its interaction with food procyanidins showed a higher interaction (synergism) for the model with all these components when compared to the interaction with the individual constituents. 78 It is important to highlight that a synergic interaction resulting in decreased oral friction has been recently proposed for wines by Brossard et al 114 This suggests that there are more mechanisms to be considered in astringency perception in wines. An example of such a complex mechanism has been observed in soft microgels food matrices (protein-, starch-, or lipid-based).…”

“…Using Cabernet Sauvignon and Carménère wines (with rough and soft/velvety sub-qualities, respectively), obtained at different harvest dates were evaluated. 114 Cabernet Sauvignon, described with a rough sub-quality, 5 showed a tendency of losing friction as ripeness progressed, expressed by a reduction on the friction coefficient. However, Carménère, described with a soft/ velvety sub-quality showed an opposite trend.…”