# Chemical Characterization and Volatile Profile of Trebbiano di Lugana Wine: A Case Study
## 1 Introduction  
Trebbiano di Lugana is a white _Vitis vinifera_ cultivar mainly cultivated in an Italian area located south near Garda lake (Verona, north of Italy). This grape variety, also known as \"Turbiana,\" is used for the production of Trebbiano di Lugana wines with recognized appellation of origin (DOC).  
Traditionally, the Trebbiano di Lugana grape was considered identical with Trebbiano di Soave and Verdicchio grape varieties, the first one also grown in Verona area, while the second one is diffused in the Marche region (center of Italy). The appellation of Trebbiano di Lugana is reserved to the Verdicchio cultivar cultivated in the Verona area. Nevertheless, the origin of these grape cultivars is still under discussion. Genetic analysis showed that cv Verdicchio and Trebbiano di Soave are identical [1], the latter being similar to Trebbiano di Lugana [2]. However, these three varieties presented distinctive tracts allowing their differentiation to other _V. vinifera_ cv. Verdicchio [3]. More recently, the genetic similarity of these three grape varieties, at least for the part of the genome analyzed, was reported by [PERSON] et al. [4], even if traces of three different biotypes of the same variety could remain in relation to phenotypical traits that are environment-dependent (terroir).  
To the best of our knowledge, the volatile profile of Trebbiano di Lugana wine has not been described yet. Among the grape varieties similar to the Trebbiano di Lugana grape, the aroma profile of wine produced with the Verdicchio grape was recently described by [PERSON] et al. [5]. The authors reported that Verdicchio wine was characterized by fermentative esters such as ethyl butyrate, phenyl acetate, ethyl acetate and isoamyl acetate, the latter being the most abundant. Terpenes, such as linalool, nerol and geraniol, were also found [5]. Recently, the aromatic complexity of Verdicchio wines was described, also relating to its aging. Younger wines were characterized by fruity and tropical notes, while aged wines were distinguished by the presence of norisoprenoids, anise and balsamic notes, related to 3-methyl-2,4-nonanedione and methyl salicylate released by precursors [6]. The presence of varietal thiols, namely 3-mercaptoethanol-1-ol and its acetate form, conferring tropical and citrus notes has been documented in Trebbiano di Lugana wine. Winemaking strategies allowing for the protection and maintenance of these desired aromas were also described [7]. Moreover, the abundance of glutathione, a natural antioxidant, resulted in particular interest for reducing the use of exogenous antioxidants, i.e., sulfur dioxide [7], and because of its important role in limiting the loss of varietal thiols [8].  
This research aimed at conducting a preliminary evaluation on some quality traits of Trebbiano di Lugana produced in different years, between 2005 and 2017, and stored in dark bottles up to 13 years from the respective winery. The potential longevity of Trebbiano di Lugana wine was considered by trying to identify those chemical, volatile and sensorial markers affected by the storage timing period, although different vintages were considered. Volatile compounds were assessed by Solid Phase Microextraction (SPME) technique coupled with gas chromatography-mass spectrometry (GC-MS) and the perceived aromatic notes were described. The ultimate goal is the presentation and discussion of a case study to understand which quality attributes, among those considered, could be used in a more structured aging trial since Trebbiano di Lugana has not been studied so far. The parameters taken into account in the study were color, phenolic components, volatile compounds and sensory characteristics, as they could be majorly affected by the storage time.