Tropical Fruit Aroma in Wine

Summary The overall goal of this project is to produce Chardonnay wines with increased tropical fruit aroma perception. In a previous study developed by Dr. Elizabeth Tomasino’s research group, we found that wines with higher concentrations of fermentation esters and volatile thiols imparted more intense tropical fruit aroma nuances. Therefore, in this projectspecific winemaking processes (skin contact, β-lyase addition, and two fermentation gradient temperature regimes) were performed with the intent to either increase or decrease these aromas in the wine. The first two processes (skin contact and β-lyase addition) are known for increasing volatile thiol concentrations in wine. The latter (fermentation temperature) is expected to increase thiol concentrations and preserve fermentation esters. The accomplishments for the project for the 2022 year include sensory analysis of wines that were scaled up, including consumer liking and emotional response. Basic wine chemical analysis and ester analysis was performed on all wines. Samples have been prepped for thiol analysis and PI has worked towards synthesizing thiol precursors, as purchasing standards has been challenging. While we cannot yet link the thiol and ester concentrations to the aromas noted in the wines in this project, wine consumers have positive emotional responses to the control, skin contact +fermentation gradient and fermentation gradient wines. The wines with only skin contact were associated with very negative emotions. Additionally, the three wines with positive aromas were described with different tropical fruit descriptors.