# Influence of Yeast Strain on Odor-Active Compounds in Fiano Wine
## 3 Results and Discussion
The only exception was for \(\beta\)-damascenone, a norisoprenoid compound that might originate from the direct degradation of grapes carotenoids, such as \(\beta\)-carotene, lutein, neoxanthin and violaxanthin, for which no significant changes were observed. Furfural had particularly high concentrations. Yeasts QA23 and D47 had about 10 times higher content than the other samples, including the control. _Lactones._ Butyrolactone was the most abundant lactone in the analyzed wines, with a significantly higher content for wines produced using CY3079. Those produced using QA23 were significantly higher in 3-hydroxy-2-pyranone, whose content in any treatment was higher than the control. _Volatile phenols._ Two of the 3 volatile phenols analyzed did not have statistically significant differences depending on the treatment, with syringol being more abundant in CY3079. What volatile phenols are always present in wines, even at very low concentrations, their contribution to the wine aroma is not always positive [4]. Their formation occurs through a decarboxylation on the p-coumaric acid and ferulic acid in a non-oxidative process by _Saccharomyces cerevisiae._  
_Furans._ 2-Propyl furan had a strong statistically lower concentration in QA23, followed by VL1. On the other hand, D47 and CY3079 had higher concentrations, with more than 3 times the abundance recorded for D47, but similar to the control. _Other compounds._ 3-Methylthiopropanol and N-2-phenyl-acetamide had a similar trend, with D47 showing the lowest content, while CY3079 and VL1 showed statistically significant higher concentrations. N-butyl-acetamide had a very similar content to the control for QA23 and VL1, while significantly (\(p<0.01\)) higher contents were observed for D47 and CY3079. Overall, our results based on the quantification of volatile compounds showed that the yeast strain used has a statistically significant impact on the majority of target volatile compounds. This result is in line with previous research showing that the yeast strain has to be selected carefully also depending on the type of wine to be produced. A recent paper by [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [6] showed that, despite the limited influence of five different commercial yeast strains on many physico-chemical parameters of sparkling wines, the impact on wine volatile compounds was statistically significant. By quantifying 20 volatile compounds and carrying out sensory analysis of the wines, the authors showed that some strains confer more floral odor notes, particularly elderflowers, while others, fruitier notes, e.g., green banana. They also reported a positive correlation of the fruity notes with a higher presence of ethyl octanoate, ethyl decanoate or di-ethyl succinate. Moreover, it was also noticed that not in all wines the inoculated yeast strain is predominant, compared to the indigenous _S. cerevisiae_ strains [7]. [PERSON], [PERSON], [PERSON], [PERSON], [PERSON] and [PERSON] [13] also tested indigenous _S. cerevisiae_ starters for Montepulciano d'Abruzzo wine production. They reported that different strains have a different kinetics during the fermentation and thus a different tendency to dominate over other strains. This leads to the production of different volatile profiles and aroma profiles, as assessed by a sensory panel. This conclusion is in line with the results reported in the present paper. Modulation of the wine flavor can also be approached from a biotechnology point of view, by working toward the development of a recombinant _S. cerevisiae_ strains that can enhance wine flavor. For example, grapes contain glycoconjugates that have a potential odor impact but are they are \"bound\" and need to be released to exert their potential activity. The main glycosylated compounds are monoterpene alcohols that can play an important role in the development of varietal aroma of wine. A wide range of yeasts could be potentially used for their glycosidase activity.