Caracterização do perfil sensorial e avaliação da tipicidade dos vinhos tintos DOP Bairrada e IGP Beira Atlântico

The distinctive Portuguese wines from Beira Atlântico region, encompassing the protected designation of origin (PDO) Bairrada and the protected geographical indication (PGI) Beira Atlântico, were investigated by a wine expert panel through descriptive analysis and through assessment of typicality. For that 19 trained tasters performed a blind sensory evaluation of 21 representative wines from those designations. The variables considered were the color tonality and color intensity, aroma intensity, 18 aroma descriptors and 14 taste descriptors. Typicality was investigated through a single question, where the assessor was asked to score if the sample is a good or bad example of the type. Of the 21 wines selected, seven were classified as PGI or Regional, eight as PDO and six as “Clássico”. Firstly, differences were analyzed between wine types considering all variables followed by clusters analyses confirmation. We could not find any difference between Regional and PDO Bairrada wines in terms of typicality and sensory profile. However the small group of “Clássico” wine was clearly identified by the tasters as being more typical, with also significant differences on sensory evaluation. Secondly, centered means analysis (CMA) of the 18 aroma and 14 taste items were performed to identify which of them are considered to be more distinctive. Thirdly, an exploratory factor analyses (EFA) by the principal component method (PCM) was applied to data, allowing identification of five vectors which aggregate the aroma items and four vectors which aggregate taste items. Finally, data collected from a sample of 20 questionnaires from a previous study based on cognitive knowledge and long term memory of 20 wine experts interviewed over the same 18 aroma variables and 14 taste variables, was analyzed under the same principal components (PC) and compared. The 21 wines representatives of PGI Beira Atlântico and PDO Bairrada can be defined as being medium-high intensity, ruby colored wines, having a woody & spice, ripe fruit aroma profile with also herbal and mineral aromas. On taste they tend to have a pronounced component of acidity & astringency, balanced with a smooth & sweet taste component, with a very persistent finishinfo:eu-repo/semantics/publishedVersio

Sensory profile of portuguese white wines using long-term memory: a novel nationwide approach

White wine sensory profiling of all 12 Protected Geographical Indications (PGIs) of mainland Portugal was achieved through completion of extended sensory questionnaires by 20 professional wine experts. No samples were assessed; the experiment was based on memory alone. Three macro-zonings were found and typicality differences were statistically validated and sensory described. PGI MINHO was found the most typical of all PGIs, with several extreme rates on Color, Aroma and Taste. SOUTHERN cluster of the four meridional PGIs presented several extreme, therefore typical, sensory assessments, mostly opposite to the profile of PGI Minho. Color tonality, alcohol and acidity were mutually related and respective variations were correlated with published findings and expressed as key factors for regional macro-zoning differentiation. Moreover, with the proposed methodology it was possible to achieve a novel nationwide sensory characterization of PGIs, overcoming ongoing macroscaling and sample representativeness limitations and envisaging new nation-sized sensory studiesinfo:eu-repo/semantics/publishedVersio

Em busca de marcadores sensoriais por entre a composição do vinho tinto: um estudo nacional inovador

The objective of this work was to verify the signaling/profiling potential of wine compounds and the physicochemical and bioclimatic winerelated measurements on a nationwide sensory scale of red wine typicality. Color tonality evolved from violet-purple in cooler northern regions to ruby-garnet in hotter southern regions. Acidity and astringency were enhanced from south to north. Conversely, alcohol and viscosity progressed southward. Bitterness was primarily affected by inland-coastal influence. The regional differentiation of astringency and bitterness introduced an orthogonal reading (N north- S south vs. E inland-W coastal, respectively), rather than a linear one, these findings adding novelty to sensory research. Additionally, several Portuguese-related studies were reviewed, and their findings were correlated with six sensory measures. Bioclimatic indexes, pH and the total phenol index were considered the strongest profilers in a nationwide assessment on red wine typicality. The ratio of the oligomeric/polymeric composition of tannins, as well as total anthocyanins, was also to be considered to be a valid sensory profiler. Several nationwide tendencies and correlations between sensory evaluations and wine chemistry may represent interesting findings and challenge unexplored ways for new researc

Interactions between wine phenolic compounds and human saliva in astringency perception

[EN] Astringency is a complex perceptual phenomenon involving several sensations that are perceived simultaneously. The mechanism leading to these sensations has been thoroughly and controversially discussed in the literature and it is still not well understood since there are many contributing factors. Although we are still far from elucidating the mechanisms whereby astringency develops, the interaction between phenolic compounds and proteins (from saliva, oral mucosa or cells) seems to be most important. This review summarizes the recent trends in the protein–phenol interaction, focusing on the effect of the structure of the phenolic compound on the interaction with salivary proteins and on methodologies based on these interactions to determine astringency

Caractérisation chimique et sensorielle des tanins du raisin et des vins rouges (application de capteurs potentiométriques)

De par leurs structures complexes, les tanins jouent un rôle essentiel en œnologie. Ils sont impliqués dans la stabilisation de la couleur et de l'état colloïdal. Ils sont responsables de la charpente, de la structure du vin mais également de défauts tels que l'excès d'astringence et d'amertume. Cette étude propose d'évaluer ces propriétés chimiques et sensorielles, mal connues aujourd'hui, à l'aide d'un système de capteurs électrochimiques appelé "langue électronique". Cette nouvelle technique s'est révélée sensible à plusieurs composés phénoliques du vin avec une bonne répétabilité. Elle a permis la discrimination en solution modèle d'extraits de tanins parmi d'autres composés phénoliques et selon leur degré de polymérisation. L'influence de la concentration en tanins, du degré de polymérisation, de la teneur en éthanol, du pH et de l'acide tartrique sur l'astringence et l'amertume d'extraits de tanins de pépins de raisins a été confirmée et a pu être corrélée aux potentiels de réponse de la langue électronique. L'application de cet outil analytique aux vins rouges a permis une discrimination selon leur cépage ou leurs modalités d'élevage. Par ailleurs, de fortes corrélations ont pu être obtenues entre les réponses de la langue électronique et les paramètres chimiques et sensoriels, tels que les concentrations en composés phénoliques, le degré de polymérisation des tanins, l'amertume et l'astringence.VILLENAVE D'ORNON-Bib. ISVV (335502201) / SudocSudocFranceF

Effect of pH, ethanol and acidity on astringency and bitterness of grape seed tannin oligomers in model wine solution

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