R. Bruno de Sousa

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.

Measurements of contaminant elements of wines by inductively coupled plasma-mass spectrometry: A comparison of two calibration approaches

The aim of the present work was to develop and validate an accurate method by ICP-MS focalized to the measurement of contaminant elements in wines, in special those with legal importance. In addition, we intended to evaluate the suitability of ICP-MS semi-quantitative methodology in order to reduce the time and cost of analysis. Twenty-six contaminant elements of wine (Li, Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, As, Se, Rb, Sr, Ag, Cd, In, Cs, Ba, Hg, Tl, Pb, Bi and U) were measured using quantitative and semi-quantitative calibration approaches, in diluted white and red wines. In an early step potential interferences caused by Cl and Ca species were evaluated, in order to establish suitable mathematical corrections. For validation of ICP-MS procedures a few elements were determined by flame and electrothermal AAS. Reference wines from 1992 year, with provisional values, were analyzed and the results showed satisfactory agreement. The semi-quantitative calibration provided slightly higher limits of detection than those obtained by the quantitative calibration, and always lower than 0.1mugl(-1), except for Fe and Zn. For most elements the recovery percentages (between 90 and 100%) and precision of the results (R.S.D. (%)<4) were similar for both modes. Differences lower than 20% of concentration was obtained for most elements. Both methodologies offer valuable alternatives to wine characterization and comparison purposes. For legal requirements control purposes, with reference to the importance of accurate results, quantitative approach is the most suitable alternative.