Resumen de Effect of ageing of sweet Sherry wines obtained from cvs Muscat and Pedro Ximénez on ethyl carbamate concentration
Mª José Ruiz Moreno, R. Castro Mejías, M.C. Rodríguez Dodero, Carmelo García Barroso
Background and Aims Ethyl carbamate (EC) is a known carcinogen that has been found in wines. The aims of this study were: (i) to study the effect of fermentation under different enological conditions on the EC concentration in sweet Sherry wines made from the two grape cultivars, Muscat and Pedro Ximénez, during three consecutive vintages (2008–2010); and (ii) to investigate the evolution of EC concentration during ageing in oak and in stainless steel.
Methods and Results Before and during ageing, the wines obtained were periodically sampled, and EC content was determined by HPLC with fluorescence detection. Mean values of EC ranged from 6.16 μg/L for samples after alcoholic fermentation to 120 μg/L for samples after 28 months of ageing in oak. Data were submitted for ANOVA and cluster analysis. It has been observed that the various factors considered (vinification conditions, ageing type, ageing time, grape cultivar and vintage) have significant influence on the EC concentration of the wines. The use of Saccharomyces bayanus instead of Saccharomyces cerevisiae reduced the EC concentration significantly. Both the use of nutrients and skin contact with pectolytic enzymes increased EC concentration. Ageing increased the EC content for all vinification conditions.
Conclusions Ageing was the most significant factor affecting EC concentration of the wines. Wines made from Muscat, fermented with S. cerevisiae and aged in oak cask for up to 28 months presented the highest EC concentration.
Significance of the Study The ageing of sweet Sherry wines in oak results in a concentration of EC higher than that from ageing of similar wines in stainless steel.
