Effect of ageing of sweet Sherry wines obtained from cvs Muscat and Pedro Ximénez on ethyl carbamate concentration

Abstract

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)(2009)(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.Keywords: ethyl carbamate, oak cask, stainless steel, sweet Sherry wine, yeast strain 396Ethyl carbamate in sweet Sherry wines

Aroma of Sherry Products: A Review

“…From a sensory point of view [ 62 , 63 ], the sweet Muscat wines fermented at low temperature (< 10 °C) with S. bayanus yeast without nutrients and pectolytic enzymes, were characterized by intense citrus and floral notes and were the best rated, while the ones obtained using nutrients were granted the lowest scores. In a follow-up study [ 64 ], the same authors observed that the use of S. bayanus significantly decreased ethyl carbamate content in the wines—a compound declared to be carcinogenic—while the use of nutrients and pectolytic enzymes increased its content levels. PX wines, with their characteristic amino acid profile, presented lower concentrations of this compound than Muscat wines.…”

Novel Analysis on Aroma Compounds of Wine, Vinegar and Derived Products

“…From a sensory point of view [62,63], the sweet Muscat wines fermented at low temperature (< 10 • C) with S. bayanus yeast without nutrients and pectolytic enzymes, were characterized by intense citrus and floral notes and were the best rated, while the ones obtained using nutrients were granted the lowest scores. In a follow-up study [64], the same authors observed that the use of S. bayanus significantly decreased ethyl carbamate content in the wines-a compound declared to be carcinogenic-while the use of nutrients and pectolytic enzymes increased its content levels. PX wines, with their characteristic amino acid profile, presented lower concentrations of this compound than Muscat wines.…”

Ethyl Carbamate in Fermented Food Products: Sources of Appearance, Hazards and Methods for Reducing Its Content

“…The type of aging also plays an important role in the formation of ethyl carbamate: when the process was carried out in oak barrels, the content of ethyl carbamate in wine was higher (57.4 µg/L) than when using stainless steel tanks (47.3 µg/L). This difference may be due to favorable conditions for the development of microorganisms during the aging of wine in oak barrels due to limited oxygen access and, consequently, an increase in the concentration of ethyl carbamate precursors [8,82].…”