Browsing by Author "Portal, Vera"
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- Envelhecimento acelerado de aguardentes vínicas na presença de fragmentos de madeira. Influência nos compostos odorantesPublication . Caldeira, Ilda; Anjos, O.; Portal, Vera; Canas, SaraA tecnologia de envelhecimento tradicional, que consiste na colocação da aguardente vínica em vasilhas de madeira durante vários anos, é uma técnica morosa e onerosa. Assim, têm vindo a ser introduzidas e desenvolvidas novas técnicas, com o intuito de optimizar o processo e reduzir os custos. Uma dessas novas técnicas consiste em introduzir pedaços de madeira (aparas, toros ou outras formas) na bebida a envelhecer, condicionada em depósitos de inox. Têm sido realizados muitos estudos em vinhos, mas em aguardentes a experimentação é escassa [1, 2]. Assim, este trabalho teve como objectivo avaliar a influência da utilização de alternativas ao envelhecimento de aguardentes em vasilhas de madeira, na composição química das aguardentes obtidas, dando particular atenção aos compostos odorantes provenientes da madeira. Para tal, uma mesma aguardente vínica da Lourinhã foi submetida a um processo de envelhecimento, com três formas de madeira: aguardente colocada em vasilha de madeira (V), aguardente colocada em vasilha de inox com introdução de madeira sob a forma de dominós (D) e aguardente colocada em vasilha de inox com introdução de madeira sob a forma de tábuas (T), tendo sido colhidas amostras de aguardente, ao fim de 180 dias de envelhecimento, para análise e quantificação dos compostos odorantes. Os resultados obtidos mostram que a forma da madeira teve um efeito altamente significativo na maioria dos compostos analisados. No caso dos compostos odorantes derivados da lenhina da madeira (fenois voláteis e vanilina), os teores mais elevados foram encontrados nas aguardentes envelhecidas na presença de fragmentos (dominós ou tábuas), enquanto para os compostos odorantes derivados das hemiceluloses da madeira (ácido acético e aldeídos furânicos) os teores mais elevados foram determinados nas aguardentes envelhecidas em vasilha de madeira. Os resultados deste trabalho sugerem a possibilidade de diferenciação química das aguardentes, em função da tecnologia de envelhecimento.
- GC-FID and GC-MS as a tool to screen the influence of wood ageing technologies in the brandies odourless and odourant compoundsPublication . Caldeira, Ilda; Anjos, O.; Portal, Vera; Belchior, A. Pedro; Canas, SaraThe maturation of wine brandies in wooden barrels cause many sensory and physicochemical changes in these alcoholic beverages, namely its flavour modification. Previous work (Caldeira et al. 2008) pointed out the most potent odourant compounds of the wine aged brandies. Some of these compounds proceed from the distillate and others are extracted from the wood. In this study it was quantified, some odourless compounds, such as methanol and higher alcohols and several odorant compounds in brandies aged in presence of two types of wood fragments (staves and tablets), from two different kinds of woods (Limousin oak wood and Portuguese chestnut wood), and compared with those found in the same with brandy aged in wooden barrels. A taster panel have also profiled these brandies and evaluated their overall quality. The methanol and higher alcohols were quantified by GC-FID equipped with a fused silica capillary column of polyethylene glycol according to the official method [NP 3263, 1990]. The odorant compounds were quantified by GC-FID and identified by GC-MS. The results showed that the ageing system is the most discriminant factor, having a significant effect on the level of several odourant compounds. The wood botanical species affected few odourant compounds. The importance of odorant compounds was also demonstrated by the high linear correlations between their contents and the intensity of several sensory attributes. The results show the possibility of using the chromatographic results as a tool to discriminate brandies produced with different ageing technologies.
- Sensory and chemical modifications of wine brandy aged with chestnut and oak woodPublication . Caldeira, Ilda; Anjos, O.; Portal, Vera; Belchior, A. Pedro; Canas, SaraThis work evaluated the sensorial and chemical modifications in brandy aged in presence of two types of wood fragments in comparison with a brandy aged in wooden barrels.
- Sensory and chemical modifications of wine-brandy aged with chestnut and oak wood fragments in comparison to wooden barrelsPublication . Caldeira, Ilda; Anjos, O.; Portal, Vera; Belchior, A. Pedro; Canas, SaraWooden barrels are used in the ageing or maturation of many alcoholic beverages, namely brandies and wines. However, the high costs related to ageing in wooden barrels have led to a search for alternative technologies. In this study we examined the application of wood fragments to the beverage in order to promote an accelerated ageing. We evaluated the sensory and chemical modifications in brandy aged in presence of two types of wood fragments, from two different woods (Limousin oak wood and Portuguese chestnut wood), and compared those with a brandy aged in wooden barrels. The results of the analysis of variance revealed more significant effects of wood botanical species than the ageing system on the sensory attributes. Concerning the ageing system, significant differences in brandy colour attributes were found, namely golden, topaz and greenish; olfactory attributes such as alcoholic, toasted and coffee; and the gustatory attribute, bitter. The brandies aged in the presence of wood tablets presented the highest intensities of topaz and greenish colour, toasted and coffee odours, while the brandies aged in wooden barrels presented the highest intensities of golden colour, alcohol odour and bitter taste. However, the overall quality of the brandies was similar. The analysis of odourant compounds showed a great discrimination of the brandies based on the ageing system. The brandies aged in wooden barrels presented the highest levels of several ethyl esters, acids, furanic aldehydes and the lowest levels of volatile phenols. Thus, considering the overall quality of the brandies, these results suggest the use of wood fragments to be an interesting alternative technology. On the other hand, the chemical analysis of the brandies showed the possibility of discriminating the ageing technologies based on odourant compound levels.