## 1 Introduction  
The tea plant has great economic importance and, after water, tea infusions are the most consumed beverages in the world; they are prepared by hot water extraction of dried leaves from _Camelia sinensis_ L. Kuntze [1, 2, 3]. According to their manufacturing, teas can commercially be classified into three main categories: non-fermented (_white_ and _green_ teas), partially fermented (_oolong_ and _paochong_ teas), and fully fermented (_black_ tea) [4, 5]. Green and black teas are widespread in the world, while the other kinds of tea (white, yellow, and oolog) are mainly consumed in producing countries [6]. Tea is characterized by important physiological and potential health benefits [7, 8, 9, 10] due to the presence of many bioactive chemical constituents. The chemical composition of the dried tea plant (green or black) includes primary metabolites such as proteins, free amino acids, carbohydrates, vitamins, minerals, and specialized metabolites, i.e., polyphenols, purine alkaloids (methyl xanthines and, above all, caffeine), chlorophyll, and other volatile and non-volatile compounds [1]. The unique combination of non-volatile solids extractable from tea leaves and the complex volatile fraction evokes tea's characteristic flavor, which is fundamental in influencing its market value and consumer choices. It is well known that the quality of food is not only guaranteed by its safety and health properties but a significant role is played by its hedonic profile, especially flavor, and appearance [11, 12, 13, 14, 15, 16, 17, 18, 19, 20]. Industrial qualification of black teas is mainly based on known quality markers belonging to the phenolic fraction of plant-specialized metabolites [1]. Available methods, some of them also normalized and standardized as ISO norms, are directed to the whole fraction (Folin-Ciocalteu test for the total polyphenol content) or specific metabolites (theaflavins and flavan-3-ols). Moreover, since the appreciation of tea infusions is strongly conditioned by flavor and appearance, quality control sometimes also includes sensory evaluation of model infusions performed by trained panels. If the chemical characterization is intrinsically objective, being directed to target fractions/analytes and based on molecular methods that can be validated according to consensus guidelines, the sensory evaluation is more complicated, time-consuming, and intrinsically less objective. It could fail in the comparative evaluation of samples over wide time frames or for high-throughput testing. Tea flavor has represented an intriguing research topic since the 1930s [5], and this area of investigation is still active today. The increase in the industrial production of _ready-to-drink_ beverages requires an in-depth knowledge of the quality of raw materials (traceability and flavor features) to obtain products with excellent yet benchmarked flavor. The literature reports several studies focused on compounds responsible for the characteristic flavor of teas, differing by geographical provenience/botanical variety. In 2006, [PERSON] and [PERSON] [21] applied the _molecular sensory science_ approach, nowadays referred to as _sensomics_, to identify and quantify key aroma compounds in the infusion prepared from Darjeeling (India) black teas. The approach includes solvent-assisted flavor evaporation (SAFE) followed by gas chromatography-olfactometry (GC-O) with aroma extract dilution analysis (AEDA) to identify potent odorants and their odor qualities. With the stable isotope dilution assay (SIDA), the accurate quantitative determination of odorants highlights those exceeding the odor threshold (OT) in the sample, thereby indicating how to reconstruct an aroma recombinates that evokes the unique and distinctive aroma identity (_aroma blueprint_) of the product [22]. The authors identified a total of 42 impacting odorants both in the leaves and in the resulting infusions with some quantitative differences.