The interaction between wine tannins and saliva proteins is responsible for wine astringency perception, producing a depletion of salivary proteins and changes on oral friction. In sensorial terms, astringency is described as a dryness and puckering sensation in the mouth, which is related to the "structure" or "body" of red wines. However, these last descriptors, as structure or body, are perceived during wine tasting and commonly related to wine viscosity. To address these differences on sensory response, we hypothesize that tannin-protein interactions could be a key factor involved in the viscosity of red wines/saliva mixtures, just as they are for astringency. We used a rheological method to study the impact of tannin-protein interaction on the viscosity of model wine-saliva systems. Mixtures of model saliva based on mucin and typical astringent compounds, as commercial tannins and gallic acid, were evaluated for their rheological behavior. The viscometric flow of the fluid mixtures was determined, and subsequently, the viscosity was evaluated at a shear rate of 60 s-1 . It was observed that red wines/saliva mixtures exhibit non-Newtonian flow and ascending tannin doses led to an increase in the apparent viscosity. Nephelometric analysis demonstrate that tannin-mucin aggregates were formed, which suggests that these complexes were potentially responsible for the viscosity increases, modifying the rheological behavior of these mixtures. Results from this work propose that tannin-protein interactions are also involved in the underlying mechanism of thickness perception of red wines and rheology could be a complementary instrumental technique for wine mouthfeel characterization. This article is protected by copyright. All rights reserved.

中文翻译：

---

基于模型系统的单宁与蛋白质相互作用的流变学研究

葡萄酒单宁和唾液蛋白之间的相互作用是造成葡萄酒涩味的原因，导致唾液蛋白的消耗和口腔摩擦的变化。在感官方面，涩味被描述为口中的干燥和起皱感，这与红葡萄酒的“结构”或“酒体”有关。然而，这些最后的描述词，如结构或酒体，是在品酒过程中被感知的，通常与葡萄酒的粘度有关。为了解决这些感官反应的差异，我们假设单宁 - 蛋白质相互作用可能是影响红葡萄酒/唾液混合物粘度的关键因素，就像它们是涩味一样。我们使用流变学方法研究单宁-蛋白质相互作用对模型葡萄酒-唾液系统粘度的影响。评估了基于粘蛋白和典型收敛剂化合物（如商业单宁和没食子酸）的模型唾液混合物的流变行为。测定流体混合物的粘度流动，随后在60 s-1 的剪切速率下评估粘度。据观察，红葡萄酒/唾液混合物表现出非牛顿流动，并且单宁剂量增加导致表观粘度增加。浊度分析表明形成了单宁-粘蛋白聚集体，这表明这些复合物可能是粘度增加的原因，改变了这些混合物的流变行为。这项工作的结果表明，单宁-蛋白质相互作用也涉及红葡萄酒厚度感知的潜在机制，流变学可能是葡萄酒口感表征的补充工具技术。本文受版权保护。版权所有。