Explorando el papel de los componentes del vino en la percepción en boca: una aproximación sensorial, instrumental y micro-estructural integrada

Resumen del trabajo presentado al 39th World Vine and Wine Congress: "Vitiviniculture: Technological advances to market challenges", celebrado del 24 al 28 de octubre de 2016 en Bento Gonçalves (Brazil).[EN]: Wine consumption generates mouthfeel sensations that can be sensory and instrumentally measured. This work is proposed to understand the role of wine components in mouthfeel perception through eight different model wines in which key wine components such as ethanol (8%), glycerol (10 g/L) and tannins (1 g/L) were present or absent. A panel of thirteen assessors was trained to evaluate the samples. The descriptors used by the trained sensory panel were divided into the visual phase (sediment, colour, viscosity), in the mouth phase (sweetness, acidity, bitterness, wood taste, astringency, dryness, earthiness, hotness mouthfeel, alcoholic feeling, viscosity) and after taste (global persistence, alcohol persistence, wood aftertaste). Once the training was complete (stdv<2.5), a balanced complete block experimental design was carried out in triplicate (three sessions) to evaluate the samples. Also, the rheological properties of the model wines were analysed using dynamic oscillatory measurement in a Kinexus rheometer (Malvern, UK) and friction measurements were performed on a Mini-Traction Machine (MTM, PCS Instruments Ltd., UK). Experiments were done in duplicate with and without artificial saliva. Dynamic light scattering was used to monitor the interaction between tannins and salivary proteins, and to determine the size of the particles. Statistical analysis was done to study the relationships among instrumental analysis (tribology, density, and viscosity) and trained panel characteristics. As expected, ethanol presence was related to the hotness mouthfeel, alcohol persistence, and alcoholic feeling; furthermore, was a driver for persistence mouthfeel (global) and increase the intensity of other attributes as bitterness wooden taste, colour and dryness. The presence of tannins was related to the high intensity of colour, astringency, and dryness, the presence of ethanol did not hide this mouthfeel, in fact, it was observed a significant synergetic effect between samples with and without ethanol. Preliminary instrumental results showed an increment of viscosity in the presence of saliva for samples without tannins, and a decrement with tannins, probably due to the precipitation of salivary proteins. Friction results showed a non-significant increase in the presence of tannins. Density was higher for those samples without ethanol and with glycerol. The research aimed to highlight the complex interactions between mouth and wine. Ethanol effects stimulating complex chemosensory circuit has been remarkable, although it was not related to viscosity or body fullness as it was thought by previous authors. More understanding of this sensory mechanism and instrumental will allow us to understand the wine desirable properties.[ES]: Las sensaciones experimentas durante el consumo de vino pueden ser medidas tanto instrumental como sensorialmente. Este trabajo propone comprender el papel de los componentes del vino en la percepción en boca a través de ocho diferentes vinos modelo en los que los componentes clave del vino, como el etanol (8%), glicerol (10 g/L) y taninos (1 g/L) estaban presentes o ausentes. Un panel de evaluadores compuesto por trece panelistas fue entrenado para evaluar las muestras. Los descriptores utilizados por el panel entrenado fueron divididos en la fase visual (sedimentos, color, viscosidad), en la fase de la boca (dulzor, acidez, amargor, sabor madera, astringencia, sequedad, arenosidad, sensación térmica, sensación alcohólica, viscosidad) y en la fase post-gusto (persistencia global, persistencia de alcohol, regusto a madera). Una vez completado el entrenamiento (STDV