STUDY OF PRODUCTION AND RELEASE OF AROMAS DURING WINEMAKING
CARRIED OUT BY DIFFERENT Saccharomyces SPECIES AND HYBRIDS

     Aroma is one of the most important attributes involved 
in wine quality. Current trend in winemaking consists of 
producing wines with different aroma nuances to offer 
variety of wines to a developing market. Several studies have 
demonstrated that low temperature fermentations favours 
aroma synthesis and retention. In this background, new wine 
yeasts able to perform fermentation at low temperatures 
improving wine aroma while maintaining good fermentation 
rates are necessary. This doctoral thesis explores the 
oenological traits of different Saccharomyces species and 
hybrids relevant for present-day wine industry, especially 
regarding aroma production, as well as the molecular bases 
underneath. This exploration has been possible using different 
biochemical, analytical chemistry and molecular techniques 
to perform enzymatic activity detection, aroma profile 
determination and transcriptome analysis in wine 
fermentations. Through this doctoral thesis the abilities of 
different Saccharomyces species and hybrids regarding 
primary aroma release and secondary aroma production, 
especially at low temperatures, has been elucidated in order 
to know the different possibilities that these yeasts offer to 
create new wines with different aromatic nuances. One of 
the general conclusions of this doctoral thesis is that 
production and release of aromas in winemaking depends 
on the strain carrying out the fermentation process. 
Nevertheless, sometimes there was a species tendency. On 
the other hand, the fact that fermentation temperature 
affects aroma synthesis but not always in the direction to 
aroma increase has been demonstrated.