Ilda Caldeira

Aroma profile of Portuguese brandies aged in chestnut and oak woods

Abstract Much research has been made on the physico-chemical composition of brandies aged in oak wood but few sensorial data are available on brandies aged in oak wood and there is no sensorial data on brandies aged in chestnut wood. In the present work a panel of tasters evaluated the aroma attributes of a Portuguese Lourinha brandy, after 4 years of ageing. The taster panel generated the 11 aroma descriptors and the brandies were evaluated based on those descriptors, with a structured scale. A two factorial experiment ( 7 woods ×3 toasting levels×3 replicates) was used to compare the brandies aged in barrels made from seven different woods and each wood was submitted to three levels of toasting: light, medium and strong, with three replicates of each essay. The analysis of variance showed significant differences between the brandies aged in the seven different woods, concerning the intensities of vanilla, woody, caramel, burned, green, tails, glue and caoutchouc. The highest intensities of caramel and burned were found in the brandies aged in chestnut wood. The toasting level of the barrels had a significant effect on the majority of the aroma descriptors, namely fruity, vanilla, woody, spicy, caramel, burned, smoke, green, tails and glue. In fact, the brandies aged on strong toasted barrels presented the highest intensities of vanilla, woody, spicy, caramel, burned, smoke and the lowest intensities of fruity, green, tails and glue. According to our previous results, this work pointed out the interesting sensorial properties of the brandies aged in chestnut, and thus shows the possibility of the use of this wood on the brandies’ ageing.

Sensory and chemical modifications of wine-brandy aged with chestnut and oak wood fragments in comparison to wooden barrels

Wooden 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.

Extraction/oxidation kinetics of low molecular weight compounds in wine brandy resulting from different ageing technologies

This study provides innovative information on the influence of new technologies of ageing (stainless steel tanks with wood staves or wood tablets of chestnut or Limousin oak), in comparison with traditional technology (oak wooden barrels), on the extraction/oxidation kinetics of low molecular weight compounds of wine brandy. The brandy was sampled and analysed by HPLC during the first year of ageing. The results show that most of the compounds tend to increase over the time, but their extraction/oxidation kinetics depend on the ageing technology. The wooden barrels promote greater enrichment in the majority of the compounds. However, gallic acid, ellagic acid and syringaldehyde, and vanillin and 5-methylfurfural, which are strong antioxidants and key-odourant compounds, respectively, present higher contents in the brandy aged with the alternative technologies. Chestnut proves to be a suitable alternative to Limousin oak for the ageing of brandy in all the studied technologies, inducing faster evolution and high quality.

Kinetics of odorant compounds in wine brandies aged in different systems.

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.

Development of blueberry liquor: influence of distillate, sweetener and fruit quantity

BACKGROUND In this work different formulations of blueberry liquor were tested and characterised based on their physico-chemical and sensory characteristics. RESULTS Three factors were evaluated: the distillate used to produce the liquor (wine spirit or grape marc spirit); the sweetener (white sugar or honey) and the fruit quantity (two doses). For each liquor, pH, total acidity, dry soluble solids content, dry extract, alcoholic strength, reducing sugars, colour intensity, methanol content, acetaldehyde and fusel alcohols were determined. Sensory tests were carried out with a trained panel. CONCLUSION The three factors studied significantly influenced the physico-chemical features of the liquors, being the quantity of fruit the most discriminating factor, except for the volatile compounds which were mainly influenced by the distillate. As regards the sensory analysis, it was found that the most appreciated liquor was that prepared with wine spirit, sugar and a lower dose of blueberry, and the less appreciated formulation was the one made with grape marc spirit, honey and a lower quantity of blueberry.

Arbutus unedo L. Spirit: Does the Water Addition Before Fermentation Matters?

The strawberry tree (Arbutus unedo L.) is a shrub that plays an important role in the territorial sustainability due to the production of a spirit known as “aguardente de medronho” made by distilling its fermented fruits. This work intends to study the influence of adding water to arbutus fruits before the alcoholic fermentation, on the chemical composition of the obtained distillates. A set of fruits from the same orchard was used to fill fermentation containers in presence and absence of water addition. After the fermentation the distillation was performed in a copper small-sized alembic (boiler-15 L capacity). In the distillates, pH, volatile acidity, titratable acidity and volatile composition were determined. At the same time, the heart fractions, obtained in an industrial copper column alembic (boiler, column-200 L capacity), proceeding from the same fermented containers were evaluated. The statistical analysis of the results shows a significant effect of the water addition on the composition of the distillates. The distillates resulting from fruits that fermented with water, present higher pH, lower acidity, lower acetaldehyde amounts and higher amounts in some fusel alcohols than the distillates resulting from fruits that fermented without water. This effect is not so pronounced in the distillates obtained in industrial conditions. In this case, the addition of water significantly influenced the amounts of titratable acidity, acetaldehyde and ethyl acetate in the first harvesting and the pH and isobutanol amounts in the second harvesting.

Physicochemical and Sensorial Characterization of Honey Spirits

Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences (p < 0.05) were also observed in the volatile composition and chromatic characteristics suggesting different production technologies. A first list of sensory attributes was obtained for this beverage. Therefore, further research must be done in order to characterize this spirit drink, which has gained market value.