Angelica Iobbi and Elizabeth Tomasino*
*Oregon State University, 3051 SW Campus Way, Corvallis, OR 97330, Corvallis, OR 97330 (elizabeth.tomasino@oregonstate.edu)

Volatile thiols are impact aroma compounds, well-known for imparting tropical fruit aromas such as passion fruit, guava, grapefruit, and citrus in white wines. More recent evidence suggests that additional aroma compounds also contribute to tropical fruit aromas, such as fermentation esters or the interactions between these volatile families. This study investigated the effects of combining fermentation esters and/or volatile thiols to determine their impact on the fruitiness aroma perception of white wines. Pinot gris wine was produced at the OSU research winery and was dearomatized using Lichrolut EN resin. Combinations of fermentation volatile compounds were added to the wine, forming the aroma base. Treatment wines were composed of additions of different concentrations and combinations of volatile thiols and/or fermentation esters. Samples were subjected to sensory analysis by 46 white wine consumers, who evaluated the orthonasal aroma of the wines and participated in check-all-that-apply (CATA). Following the results obtained by CATA, samples were subjected to a sensory descriptive analysis (SDA) panel, where 13 trained panelists evaluated the intensity of the most-used aroma attributes elicited by consumers. CATA results were analyzed using correspondence analysis and SDA data was analyzed by discriminant analysis. Volatile thiols without esters contributed to earthy and grassy aromas. Overall, tropical fruit aromas were detected in the several treatments containing combinations of fermentation esters and fermentation esters + volatile thiols. Differences in the intensity of the aroma attributes were observed. This study showed that esters and thiols are necessary for tropical fruit aroma causation in white wines. Therefore, grapegrowers and winemakers wishing to enhance the tropical fruit aroma of their wines should adapt viticultural and winemaking conditions to increase the concentrations of both aroma families.

Funding Support: American Vineyard Foundation