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Abstract(s)
Com o objetivo de obter o melhor de cada infusão em termos sensoriais, é necessário otimizar os fatores que mais influenciam a sua preparação, desde a qualidade da água, a qualidade da matéria-prima, a concentração, a temperatura da água e o tempo de infusão. Para além disso, torna-se necessário estudar se existe alguma correlação entre a preferência dos consumidores e a variação de cor, que possa resultar de diferentes modos de preparação de infusões.
Desta forma, o principal objetivo deste trabalho é a otimização das condições de preparação de infusão temperatura da água e tempo de infusão para as ervas aromáticas limonete, erva-príncipe, hortelã-pimenta e tomilho-limão. Para tal foram utilizados um total de dez binómios tempo de infusão / temperatura da água, apresentados aos consumidores de forma balanceada para a avaliação da sua aceitação, aplicando um método estatístico Superfície de Resposta. Recorreu-se à metodologia de colorimetria, utilizando o sistema CIELAB, para medição complementar da cor.
Diferentes infusões ervas aromáticas requerem diferentes condições de preparação, sendo possível identificar que os pontos ótimos de infusão se situam entre os 4 e 8,5 minutos e entre os 92 e os 99 ºC, respetivamente para o tempo e temperatura de infusão. Para além disso, binómios tempo / temperatura com maior aceitação, estão associados a um maior número de características positivas.
Através da colorimetria, verificou-se que existe relação entre a cor e a preferência do consumidor, tendo-se verificado que para qualquer uma das ervas aromáticas, os binómios tempo / temperatura destacados com maior número de atributos positivos, apresentaram menores valores de luminosidade. Relativamente aos valores de cromaticidade, quando estes são mais elevados, há uma maior preferência, embora tal fato seja apenas constatável nas infusões de limonete e erva-príncipe. No que diz respeito à tonalidade, os resultados demonstraram que embora diferentes binómios de tempo / temperatura resultem em intensidades de cor diferentes, para todas as ervas aromáticas, exceto na erva-príncipe, todos se encontram numa zona de cor característica.
Em conclusão, a máxima aceitação sensorial ocorre nas combinações tempo / temperatura: 6 min / 96 ºC, 8,5 min / 99 ºC, 4 min / 95 ºC e 7 min / 92 ºC para as infusões de limonete, erva-príncipe, hortelã-pimenta e tomilho-limão, respetivamente.
In order to obtain the best out of each infusion in sensory experience, it is necessary to optimize the factors that influence their preparation, such as the water quality, the quality of the raw material, concentration, temperature of the water and the infusion time. Moreover, it becomes necessary to study whether there is any correlation between consumer preference and color variation that can result from different forms of preparation of infusions. Thus, the main objective this work is to optimize the preparation conditions (water temperature and infusion time) for lemon verbena, lemongrass, white peppermint and lemon thymus. To this end, we have used a total of ten binomials “infusion time / temperature of the water” presented to acceptance evaluation in a random order, by applying the statistical method Response Surface. Resorted to the colorimetry method using the CIELAB system, to complement the color measurement. Different herbs require different conditions of preparation, it is possible to identify that the optimal points of infusion are between 4 and 8.5 minutes and between 92 and 99 °C. Through the analysis of open-ended comments it was possible to study the positive and negative attributes associated with each of the time / temperature infusion preparation. In addition, time / temperature binomials with greater acceptance, are associated with a greater number of positive characteristics. By colorimetry, it was found that there is relationship between color and consumer preference, and it was found that for any of herbs, the time / temperature binomials highlighted with higher ratio values and / or more of positive attributes had lower brightness values. With regard to chromaticity values, there is a greater preference when they are higher, although this fact is only noticeable in the infusions of verbena and lemongrass. With regard to the hue, althought the combinations of different time and temperature gave a differents colour intensity samples, for all the herbal plants, excluding lemongrass, the colours is in an expectable and characteristic range. Thus, the maximum sensory acceptance occurs in the following infusion time / temperature of the water combinations: 6 min / 96 °C, 8,5min / 99 °C, 4min / 95 ºC and 7 min / 92 °C for infusions of lemon verbena, lemongrass, white peppermint and lemon thymus, respectively.
In order to obtain the best out of each infusion in sensory experience, it is necessary to optimize the factors that influence their preparation, such as the water quality, the quality of the raw material, concentration, temperature of the water and the infusion time. Moreover, it becomes necessary to study whether there is any correlation between consumer preference and color variation that can result from different forms of preparation of infusions. Thus, the main objective this work is to optimize the preparation conditions (water temperature and infusion time) for lemon verbena, lemongrass, white peppermint and lemon thymus. To this end, we have used a total of ten binomials “infusion time / temperature of the water” presented to acceptance evaluation in a random order, by applying the statistical method Response Surface. Resorted to the colorimetry method using the CIELAB system, to complement the color measurement. Different herbs require different conditions of preparation, it is possible to identify that the optimal points of infusion are between 4 and 8.5 minutes and between 92 and 99 °C. Through the analysis of open-ended comments it was possible to study the positive and negative attributes associated with each of the time / temperature infusion preparation. In addition, time / temperature binomials with greater acceptance, are associated with a greater number of positive characteristics. By colorimetry, it was found that there is relationship between color and consumer preference, and it was found that for any of herbs, the time / temperature binomials highlighted with higher ratio values and / or more of positive attributes had lower brightness values. With regard to chromaticity values, there is a greater preference when they are higher, although this fact is only noticeable in the infusions of verbena and lemongrass. With regard to the hue, althought the combinations of different time and temperature gave a differents colour intensity samples, for all the herbal plants, excluding lemongrass, the colours is in an expectable and characteristic range. Thus, the maximum sensory acceptance occurs in the following infusion time / temperature of the water combinations: 6 min / 96 °C, 8,5min / 99 °C, 4min / 95 ºC and 7 min / 92 °C for infusions of lemon verbena, lemongrass, white peppermint and lemon thymus, respectively.
Description
Keywords
Infusão Ervas aromáticas Tempo de infusão Temperatura da água Aceitação sensorial Colorimetria Herbal tea Herbs Infusion time Water temperature Sensory acceptance Colorimetry