Análise sensorial de produtos têxteis

Abstract

Esta investigação tem como objectivo definir os atributos do toque, da visão e visiotácteis (toque e visão em simultâneo) valorizados pelo consumidor no acto de aquisição de produtos têxteis e compreender cientificamente a percepção psicológica e as sensações de conforto proporcionadas pelos mesmos. Para a definição destes atributos, foi utilizada a Análise Sensorial, uma metodologia já aplicada a outras indústrias, nomeadamente à indústria alimentar, cosmética e automóvel. Esta metodologia é desenvolvida em função das respostas dadas pelos sujeitos aquando de uma percepção sensorial, por utilização dos sensores humanos (sentidos). “Análise sensorial é um método científico usado para caracterizar, medir, analisar e interpretar as reacções sentidas, como são percebidas pelos sentidos da visão, do toque, do paladar, do olfacto e da audição”. Seguindo esta metodologia, esta dissertação teve como fases principais a selecção e definição dos atributos do toque (sem a visão), da visão (sem o toque) e visiotáctil (toque e visão em simultâneo) de materiais têxteis acabados, tal como chegam ao consumidor, efectuada por um painel de consumidores sem qualquer conhecimento de avaliação sensorial. Na primeira fase foi realizada a selecção dos atributos do toque, por um painel constituído por indivíduos portugueses, recrutados voluntariamente (homens e mulheres) e seleccionados de acordo com a idade, formação pessoal e profissional, capacidade de expressão verbal, capacidade de comunicação, atitude e criatividade. Paralelamente, e usando a mesma metodologia, foi criado um painel constituído por indivíduos franceses. O painel português definiu 15 atributos do toque (quente - fresco, flexível - rígido, áspero - macio, liso - rugoso, leve - pesado, fino - grosso, pilosidade, escorregadio, pegajoso, fofo, granulado, cair, recuperação da forma, amarrotar e elasticidade). O painel francês definiu 15 atributos, sendo 14 deles comuns a ambos os painéis. Os atributos definidos de forma totalmente oposta foram os atributos fofo (português) e gorduroso (francês). Para quantificar os 15 atributos do toque, foi criado um painel de peritos em avaliações sensoriais, devidamente treinado para classificar cada atributo de forma repetitiva e em concordância com os restantes indivíduos do grupo. Esta etapa constituiu o instrumento de medida do toque. A escala estruturada de 0-10 foi definida como sendo a melhor escala de avaliação para avaliações sensoriais do toque. Dois conjuntos de materiais têxteis, um com estímulos próximos e outro com estímulos distintos, foram sujeitos a avaliações sensoriais pelos 2 painéis (português e francês). Os resultados mostraram que as avaliações dos dois painéis são similares para os 14 atributos comuns. Numa fase posterior, e por recurso a um outro painel de consumidores (37 indivíduos), foram definidos 10 atributos de visão (brilho, fresco - quente, fofo, pilosidade, áspero - macio, liso - rugoso, fino - grosso, aberto - fechado, transparente e uniformidade). A mesma metodologia foi aplicada à selecção dos atributos visiotácteis, sendo seleccionados 16 atributos (fresco - quente, áspero - macio, flexível - rígido, liso - rugoso, fino - grosso, leve - pesado, transparente, amarrotar, pegajoso, escorregadio, brilho, recuperação da forma, vivacidade da cor, elasticidade, fofo e pilosidade). Para a exploração dos resultados, foi construída uma base de dados actualizável que foi utilizada no tratamento estatístico dos mesmos. O recurso a ferramentas estatísticas uni e multivariadas permitiu tratar e analisar os dados e ajudar a tomada de decisões em relação aos resultados obtidos. A comparação dos atributos seleccionados do toque, visão e visiotáctil permite concluir que independentemente do sentido solicitado, isoladamente ou pela sua interacção, as características valorizadas pelos consumidores portugueses inquiridos não são muito diferentes. Esta investigação é o primeiro passo neste domínio, sendo, por isso, um passo importante no que respeita à avaliação sensorial do toque, da visão e visiotáctil, pois possibilita aos designers de produtos têxteis desenvolverem novos produtos, direccionando-os para o segmento de mercado correspondente, de acordo com as preferências dos consumidores respectivos. Este trabalho contribuiu para objectivar a medição e normalização do toque, em Portugal e, pela comparação dos painéis (português e francês), uniformizar a percepção do toque. A definição e comparação dos atributos do toque, realizada por ambos os painéis, mostrou que catorze deles são comuns aos dois países, o que permite abrir caminho para a criação de um perfil sensorial europeu de produtos têxteis.

Cette recherche a pour but définir les attributs du toucher, de la vision et visio-tactiles (toucher et vision en simultané) valorisés par les consommateurs quand ils achètent des produits textiles et comprendre scientifiquement la perception psychologique et les sensations de confort provoqués par ces matériaux. Pour la définition de ces attributs, l’Analyse Sensorielle a été utilisée. Il s’agit d’une méthodologie déjà appliquée à d’autres industries, notamment à l’industrie alimentaire, le domaine des cosmétiques et le secteur automobile. Cette méthodologie est développée en fonction des réponses données par les sujets lors d’une perception sensorielle, par l’utilisation des capteurs humains (sens). “L’Analyse Sensorielle est une méthode scientifique utilisée pour caractériser, mesurer, analyser et interpréter les réactions senties, comme elles sont perçues par les sens de la vision, du toucher, du goût, de l'odorat et de l'audition”. En suivant cette méthodologie, ce travail de thèse a eu comme phases principales la sélection et la définition des attributs du toucher (sans vision), de la vision (sans toucher) et visio-tactile (toucher et vision en simultané) de matières textiles finies, telles qu’elles sont présentées au consommateur. Les tests sont réalisés par un panel de consommateurs, n’ayant aucune connaissance de l'évaluation sensorielle. Dans la première phase, la sélection des attributs du toucher a été réalisée, par un panel constitué de sujets portugais, volontaires composés d’hommes et de femmes et sélectionnés selon leur âge, formation personnelle et professionnelle, capacité d'expression verbale, capacité de communication, attitude et créativité. Parallèlement, et en utilisant la même méthodologie, a été créé un panel constitué de sujets français. Le panel portugais a défini 15 attributs du toucher (chaud - frais, flexible - rigide, rugueux - doux, lis - rugueux, léger - pesé, fin - épais, pilosité, glissante, visqueuse, souple, granulée, tomber, récupération de la forme, froisser et élasticité). Le panel français a défini 15 attributs, 14 d'eux étant communs aux deux panels. Les attributs spécifiques à chaque panel ont été les attributs souple (portugais) et gras (français). Pour quantifier les 15 attributs du toucher, un panel d'experts a été créé en évaluations sensorielles, qui a été entraîné pour classer chaque attribut avec répétibilité et en accord avec les autres individus du groupe. Cette étape a constitué l'instrument de mesure du toucher. L'échelle structurée de 0-10 a été définie comme étant la meilleure échelle d'évaluation pour des évaluations sensorielles du toucher. Deux ensembles de produits textiles, un avec des stimulus proches et un autre avec des stimulus distinctes, ont été soumis à des évaluations sensorielles par les 2 panels (portugais et français). Les résultats ont montré que les évaluations des deux panels sont semblables pour les 14 attributs communs. Dans une phase postérieure, et en utilisant un autre panel de consommateurs (37 personnes), 10 attributs de vision ont été définis (brillant, frais - chaud, souple, pilosité, rugueuse - doux, lis - rugueux, fin - épais, ouverte - fermé, transparent et uniformité). La même méthodologie a été appliquée à la sélection des attributs visio-tactiles, en ayant sélectionné 16 attributs (frais - chaud, rugueux - doux, flexible - rigide, lis - rugueux, fin - épais, léger - lourd, transparent, froisser, visqueux, glissant, brillant, récupération de la forme, vivacité de la couleur, élasticité, souple et pilosité). Pour l’exploration des données, il a été construit une base de données actualisable, qu’a été utilisée dans leurs traitements statistique. Le recours à des outils statistiques uni et multivariées a permit de traiter et d’analyser les données et d’aider aux prises de décisions par rapport aux résultats obtenues. La comparaison des attributs sélectionnés du toucher, vision et visio-tactile permet de conclure qu'indépendamment du sens demandé, isolé ou par leur interaction, les caractéristiques valorisées par les consommateurs portugais enquêtés ne sont pas très différentes. Cette recherche est la première étape dans ce domaine, en étant, donc, une étape importante en ce qui concerne l'évaluation sensorielle du toucher, de la vision et visio-tactile. Elle doit permettre aux designers de produits textiles de développer de nouveaux produits, en les dirigeant pour le segment du marché correspondant, conformément aux préférences des consommateurs respectifs. Ce travail a contribué à objectiver la mesure et la normalisation du toucher, au Portugal et, par la comparaison des panels (portugais et français), uniformiser la perception du toucher. La définition et la comparaison des attributs du toucher, réalisées par tous les deux les panels, a montré que quatorze d’entre eux sont communs aux deux pays, ce qui peut permettre la création d'un profil sensoriel européen de produits textiles.

The main goal of this research is to define the attributes of touch, vision and visiotactile (touch and vision simultaneously) valorized by the consumer at the moment of textile products acquiring, and scientifically understand the psychological perception and the comfort sensations proportioned by them. For the definition of such attributes, was applied the Sensory Analysis, a methodology also applied in other industries, namely food, cosmetic and automobile. This methodology uses the human being as instrument and is developed in function of the answers given by the subjects at the moment of the sensory perception. “Sensory Analysis is a scientific methodology used to characterize, measure, analyze and interpret the reactions, as they are perceived by the senses of vision, touch, palate, smell and audition.” Following this methodology, this dissertation had as main phases the selection and definition of the attributes of touch (without vision), vision (without touch) and visiotactile (touch and vision simultaneously) of the finished textile products, as they are presented to the consumer. This selection and definition of the attributes will be performed by a panel of consumers without any knowledge about sensory evaluation. Firstly, the selection of touch attributes was performed by a panel of Portuguese individuals, voluntarily recruited (men’s and women’s), and selected according to their age, personal and professional formation, verbal expression abilities, communication capacity, attitude and creativity. Parallelly, and using the same methodology, a panel of French individuals was created. The Portuguese panel defined 15 attributes of touch (cold - warm, supple - rigid, sleek - rugous, smooth - rougth, light - heavy, thin - thick, pilous, slippery, stick, fluffy, granulous, falling, shape recovery, crumple and elastic). The French panel defined 15 attributes, being 14 common to both panels. The attributes defined differently were fluffly (by the Portuguese panel) and grease (by the French panel). The main goal of this research is to define the attributes of touch, vision and visiotactile (touch and vision simultaneously) valorized by the consumer at the moment of textile products acquiring, and scientifically understand the psychological perception and the comfort sensations proportioned by them. For the definition of such attributes, was applied the Sensory Analysis, a methodology also applied in other industries, namely food, cosmetic and automobile. This methodology uses the human being as instrument and is developed in function of the answers given by the subjects at the moment of the sensory perception. “Sensory Analysis is a scientific methodology used to characterize, measure, analyze and interpret the reactions, as they are perceived by the senses of vision, touch, palate, smell and audition.” Following this methodology, this dissertation had as main phases the selection and definition of the attributes of touch (without vision), vision (without touch) and visiotactile (touch and vision simultaneously) of the finished textile products, as they are presented to the consumer. This selection and definition of the attributes will be performed by a panel of consumers without any knowledge about sensory evaluation. Firstly, the selection of touch attributes was performed by a panel of Portuguese individuals, voluntarily recruited (men’s and women’s), and selected according to their age, personal and professional formation, verbal expression abilities, communication capacity, attitude and creativity. Parallelly, and using the same methodology, a panel of French individuals was created. The Portuguese panel defined 15 attributes of touch (cold - warm, supple - rigid, sleek - rugous, smooth - rougth, light - heavy, thin - thick, pilous, slippery, stick, fluffy, granulous, falling, shape recovery, crumple and elastic). The French panel defined 15 attributes, being 14 common to both panels. The attributes defined differently were fluffly (by the Portuguese panel) and grease (by the French panel). For the quantification of the 15 touch attributes, a panel of sensory evaluation experts specifically trained to classify each attribute in a repetitive way but in accordance with the remaining individuals of the group. This stage constitutes the instrument of touch measurement, where a structured scale from 0 to 10 was defined as the best scale for the touch sensory evaluation. Two collections of textile products, one with similar stimulus and the other with opposite stimulus, were subjected to the evaluation by both panels (Portuguese and French). The results showed similar evaluations by both panels for 14 attributes. In a following stage, and using another consumer’s panel (37 individuals), non trained for the sensory evaluation, 10 vision attributes were defined (bright, cold - warm, fluffy, pilous, rough - smooth, sleek - rugous, thin - thick, tight - loose structure, transparent and uniformity). Finally, using the same methodology and a new panel, 16 visiotactile attributes were selected (cold - warm, supple - rigid, sleek - rugous, smooth - rougth, light - heavy, thin - thick, pilous, slippery, stick, fluffy, shape recovery, crumple, elastic, bright, transparent and lively colour). For the results exploitation, a data base was constructed and applied on their treatment. The use of uni and multivaried statistical tools allowed the treatment and analysis of the data, helping on the final conclusions achievement. The comparison between the selected attributes of touch, vision and visiotactile was performed, being possible to conclude that, independently of the sense, isolated (only touch) or integrated (touch and vision), the characteristics valuated by the Portuguese consumer’s are the same. This research is an important step in what concerns touch, vision and visiotactile sensory evaluation, allowing to designers the development of new products, guiding them to the correct market segment according to the consumer’s preferences. This work contributed to objectify the touch measurement and normalize it in Portugal and, by the comparison of both panels (Portuguese and French), uniformize the touch perception. The definition and comparison of touch attributes, performed by both panels, showed that 14 of them are common to both countries, which allowed the creation of a new sensory European profile of textile products.