The aroma diversity of Italian white wines: a further piece added to the D-Wines project

The wide ampelographic heritage of the Italian wine grape varieties represents a richness in terms of biodiversity and potential market value. According to the wine sector informative news, a rise in diversity will come into play due to the supply challenges of 2021 so that the industry will continue to push for a more diverse range of wines. “Wine drinkers, who are naturally curious, will embrace the opportunity to branch out”, due to a trend to a “palate expansion and consumer curiosity” foreseen in 2022 (1). The report “White Wine Market” signed by the analysis company “Fact Market Research”, forecasts the boom in the growth of white wine consumption on the global market (2).Then, all actions aimed at valorizing and improvi The wide ampelographic heritage of the Italian wine grape varieties represents a richness in terms of biodiversity and potential market value. According to the wine sector informative news, a rise in diversity will come into play due to the supply challenges of 2021 so that the industry will continue to push for a more diverse range of wines. “Wine drinkers, who are naturally curious, will embrace the opportunity to branch out”, due to a trend to a “palate expansion and consumer curiosity” foreseen in 2022 (1). The report “White Wine Market” signed by the analysis company “Fact Market Research”, forecasts the boom in the growth of white wine consumption on the global market (2).Then, all actions aimed at valorizing and improving knowledge on products from the wide diversity of Italian native varieties can be impactful for the wine sector. The Diversity of Italian Wines (D-Wines) project aims to get a wide chemical, biochemical, and sensory multi-parametric dataset on Italian wines (3,4,5). In this context, the aroma of 18 mono-varietal white wines (Albana, Arneis, Cortese, Erbaluce, Garganega, Gewürztraminer, Greco di Tufo, Falanghina, Fiano, Lugana, Müller Thurgau, Nosiola, Pallagrello Bianco, Pinot Grigio, Ribolla Gialla, Verdicchio, Vermentino, Vernaccia di S. Gimignano) was investigated. A total of 240 labels (vintage 2019) was analyzed through a descriptive sensory assessment (orthonasal, retronasal, taste, mouthfeel) performed by 12 trained wine experts, and a sorting task carried out by 12 enologists (orthonasal, retronasal) based on a pre-defined list of aroma descriptors. Both intra- and inter-varietal sensory differences were highlighted by ANOVA (p<0.05) and Hierarchical Clustering Heatmap Analysis (HCHA) performed on odor intensities of descriptive analysis. 100% of Gewürztraminer wines were grouped together in a sub-cluster correlated to floral (rose, orange blossom), mango and vanilla odors, 62% of Müller Thurgau were closely clustered and correlated to thiolic (cat pee/box tree), fruity (passion fruit, grapefruit) and vegetal descriptors. The dendrogram mostly sorted the 240 wines into inter-varietal clusters. Multidimensional Scaling (MDS) and Agglomerative Hierarchical Clustering (AHC) of sorting data, provided intra-variety sensory maps showing how enologists grouped wines according to aroma similarities. A list of descriptors related to global sensory characteristics of samples within each group, was obtained. Both descriptive and sorting results, showed significant correlations with VOCs compositions. This study provides a first comparative picture of the diverse sensory characteristics of white Italian wines, including some that have never been investigated before. The D-Wines project results will provide valuable information to winemakers, helping the improvement of the sensory consistency, quality, marketing communication and attractiveness of Italian wines