Teste Repositóri
2014-01-01
Resultados de pesquisa
Foram encontrados 19 registos.
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.
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 Portugu...
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.
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 ...
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 ...
