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This study attempted to apply a rapid method for the determination of methanol,
acetaldehyde and ethyl acetate in wine spirits, brandies and grape marc spirits, using
Fourier Transform Infrared – Attenuated Total Reflectance (ATR) Spectroscopy.
Evaluation of alcoholic beverages with wild berries: alcoholic beverages with juniper berry and blueberry liquor.
Só está disponível o resumo.
The alcoholic drink called “aguardente de zimbro” is normally presented at touristic
documentation about “Serra da Estrela” and included in the food heritage of the region.
However, there is a lack of technical and scientific information about this beverage.
This work intends to achieve a first characterization of this product concerning its technology,
and its sensory properties and physico-chemical characteristics. A few number of commercial
samples of this product and other alcoholic beverages made with juniper were analyzed. It
was performed several analytical determinations to the samples, namely alcoholic strength,
dry matter, total acidity, fixed acidity, volatile acidity, pH, chromatic characteristics,
methanol, acetaldehyde and ethyl acetate in order to characterize analytically the juniper
spirits, namely the Portuguese ones. It was also done the descriptive sensory analysis of the
beverages.
Based on the results the three Portuguese commercial beverages “Aguardente de zimbro”,
which are currently in the market, seem to be made from three different alcoholic distillates
(grape marc spirit, wine spirit and arbutus spirit).
The three commercial beverages presented a yellowish colour. However, the three beverages
presented a quite different flavour profile, so further research is needed in order to establish
and understand the sensory profile of the traditional beverage.
No presente estudo pretendeu-se compreender o efeito da variação do número de pontos da suavização espectral (ou filtro digital) no desenvolvimento de modelos de calibração por FTIR-ATR utilizando técnicas PLS-R para determinações rápidas do teor em metanol e do teor alcoólico em aguardentes.
De acordo com o descrito em ANJOS et al. (2016) as zonas espectrais identificadas foram 1607-977 cm-1 e 3057-2864 + 1292-663 cm-1 respetivamente para o teor em metanol e teor alcoólico, com coeficientes de determinação superiores a 96,3 %. O valor de RPD apresenta qualidade suficiente para utilização em laboratório de controlo de qualidade.
Foi avaliada a robustez dos modelos para 5, 9, 13, 17, 21 e 25 pontos de suavização para o pré-processamento usando a Primeira Derivada (1stDer), aplicando o algoritmo de Savitzky-Golay.
Application of GC-MS to characterize the volatile composition of fruit distillates made with honey.
Aging systems of wine brandies have been a target of investigation to reduce the costs and aging time. In this study, the extractives and Klason lignin contents of wood fragments used in the aging of wine brandies in stainless steel tanks were evaluated. Two types of wood fragments, known as staves and tablets, and two wood botanical species, Limousin oak (Quercus robur L. from the Limousin region of France) and Portuguese chestnut (Castanea sativa Mill.), with heavy toasting levels were used. The wood extractive and Klason lignin contents were analyzed before and 30 months after the aging of wine brandy. The results showed that the chestnut wood presented the highest content of extractives, while the Klason and total lignin contents were higher in the oak wood. A highly significant effect from the tablets was found on the extractives and Klason lignin contents, while the soluble lignin content was more affected by the staves. Oxygenation of the wine brandies during the aging process negatively affected the release of extractives and lignin from the wood to the brandy, and therefore will impact the overall quality of the brandy.
This work presents the determination of principal volatile compounds (acetaldehyde, ethyl acetate, methanol, 2-butanol, 1-propanol, 2-methyl-
1-propanol, 2-propen-1-ol, 1-butanol, 2-methyl-1-butanol and 3-methyl-1-butanol) in wine spirits, brandies and grape marc spirits by GC-FID.
The method was evaluated in terms of suitability of chromatographic system, accuracy, precision, linearity and detection and quantifi cation
limits. The method showed good accuracy for the majority of the compounds and it presented linearity and precision for all compounds.
Based on these results the method seems suitable for quality control of marc spirits and wine spirits.
The 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.
A 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.
Comunicação oral da qual só está disponível a apresentação.
This 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.
The Fourier transform infrared (FTIR) spectroscopic method with attenuated total reflectance (ATR) was used for predicting the alcoholic strength, the methanol, acetaldehyde and fusel alcohols content of grape-derived spirits. FTIR-ATR spectrum in the mid-IR region (4000-400 cm(-1)) was used for the quantitative estimation by applying partial least square (PLS) regression models and the results were correlated with those obtained from reference methods. In the developed method, a cross-validation with 50% of the samples was used for PLS analysis along with a validation test set with 50% of the remaining samples. Good correlation models with a great accuracy were obtained for methanol (r(2)=99.4; RPD=12.8), alcoholic strength (r(2)=97.2; RPD=6.0), acetaldehyde (r(2)=98.2; RPD=7.5) and fusel alcohols (r(2) from 97.4 to 94.1; RPD from 6.2 to 4.1). These results corroborate the hypothesis that FTIR-ATR is a useful technique for the quality control of grape-derived spirits, whose practical application may improve the efficiency and quickness of the current laboratory analysis.
Avaliação da robustez de modelos derivativos PLS-R em espectroscopia usando o número de pontos da suavização espectral.
Comunicação apresentada no 8.º Simpósio de Vitivinicultura do Alentejo que decorreu em Évora de 5 a 7 de Maio de 2010.
The odorants compounds of aged wine brandies comprise compounds deriving from the wood, from the distillate and from the reactions that occur inside the barrel. The aim of this work was to study the kinetics of the odorant compounds of a wine brandy during two years of ageing in two ageing systems. The odorant compounds in the analysed brandies changed significantly over the time, but with different evolution patterns. The wood related compounds increased over time, with the highest increase in the first months of ageing. The kinetics of cis, trans-β-methyl-γ-octalactone, acetovanillone and of seven volatile phenols are established for the first time in brandies. Moreover, a significant effect of the ageing system was found on the kinetics of the wood related compounds. These results pointed out the interest of these compounds as a tool to discriminate different ageing technologies.
This study provides innovative information on the simultaneous use of Limousin oak and chestnut wood in the ageing of wine brandy. Ageing was performed in 650-L wooden barrels and in 3000-L stainless steel tanks with staves over a 2-year period. Effect of both kinds of wood in the brandy features depended on the ageing technology. Stainless steel tanks with staves originated lower enrichment of the brandy in dry extract (0.89 vs. 1.25 g L−1), total phenolics (22.33 vs. 29.40) and low molecular weight extractable compounds (119.83 vs. 231.65 mg L−1), but promoted a faster evolution of the analytical colour (lower L*, higher C*, a* and b*) and sensory colour (topaz and greenish vs. golden). The aroma and flavour profiles of the brandy were not significantly influenced by the ageing technology. Therefore, it is a promising option for both ageing technologies because it ensures the quality of brandy, together with a lower cost of the wood and exemption of the blending operation.
Antioxidant ativities of wine spirits aged by a sustainable technology using chestnut wood staves and micro-oxygenation.
