# Profiling Croatian Whisky Using GC/MS-MS and UHPLC-QTOF
## 3 Results and Discussion
### Aromatic Profile of Croatian Whisky Determined by SPME-GC-MS
#### 3.3.6 Lignans and Phenolic Compounds  
The impact of lignans and phenolic compounds on whisky flavor is less extensively documented compared to the well-known compounds listed above, yet they play a significant role as part of the complex mix of oak-derived compounds. Lignans such as lyoniresinol and related glucosides are derived from oak wood, potentially adding astringent, bitter, or sometimes spicy notes to whisky. However, their sensory impact is not as extensively studied in comparison to key compounds like vanillin and syringaldehyde. While lignans are not typically the primary focus in whisky flavor research, they still contribute to the complexity of whisky's flavor profile. The specific sensory attributes of lyoniresinol derivatives in whisky have not been as extensively studied as those of vanillin [37]. 1-Acetoxyppinoresinol, also found in oak, is associated with woody or resinous flavor, potentially contributing to the bitter or astringent aspects of whisky. Although these lignans are not typically a focus in whisky flavor research, they can add to the complexity of the whisky's profile. Scopoletin, a coumarin found in the wood of certain plants including oak, may be present in whisky in trace amounts, depending on the raw materials and aging conditions. It could potentially contribute earthy or medicinal notes to the flavor profile. Coniferyl aldehyde and sinapoyl aldehyde are both phenolic aldehydes derived from lignin degradation. They could influence spicy, smoky, or woody characteristics of whisky. Their contribution would be influenced by the exact processes, such as cask preparation and aging conditions. Gallagic acid and ellagic acid both contribute significantly to the complexity of whisky, often imparting a dry, puckering quality due to their astringency. Ellagic acid, in particular, is known for its role in the perception of oakiness in whisky. It is released during the aging process and has a high antioxidant capacity, which can influence the color stability and aging potential of whisky. American oak, with its higher cis-to-trans whisky lactone ratio (8:1) and greater concentrations of ellagic and gallic acids, imparts sweeter, coconut-like flavors compared to the more tannic and subtle European oak. Therefore, it is suggested that spirits maturing in American oak can have creamier, more coconut-like aromas [54; 56; 57]. Gallagic acid, derived from ellagitannin hydrolysis, is not a primary flavor compound but might be a part of tannin composition affecting the astringency and mouthfee! of whisky. The presence of salvigenin in whisky is less documented, but like other phenolic compounds, it may contribute to the overall astringency or might provide subtle herbal nuances to the flavor. 3-O-methyl ellagic acid is likely to contribute to the bitter and astringent aspects of the whisky flavor profile. Both salvigenin and 3-O-methyl ellagic acid are more specific derivatives of ellagic acid, related to the oak wood tannins. Moreover, they can contribute to the overall depth of flavor through their bittering and astringency properties, but their precise contributions to whisky's flavor profile are not as well characterized as ellagic acid. Perulactone, sometimes present in oak-aged spirits, can impart a spicy, cinnamon-like flavor. Over time, these components are extracted into the whisky, resulting in older whiskies having more intense and complex flavors compared to younger ones. The type of oak used for the barrels, as well as the degree of barrel charring or toasting, and the previous contents of the cask (such as sherry or bourbon), can all impact the levels of these compounds and subsequently influence the flavor of the whisky. Factors such as wood type, origin, cask size, and charring level will also influence the release and concentration of chemicals in whisky. Environmental conditions, including temperature, humidity, and storage location also play a crucial role in further reactions. Research has shown that toasting and charring significantly affect compound concentrations like vanilla.