Introduction While the use of proprietary EI flavor databases has been used in wineries for many years, few labs have applied metabolomic protocols to fully characterize secondary grape and yeast metabolites. To this aim we have applied metabolic workflows to processed Cabernet Sauvignon grapes. These approaches include recursive analysis as well as accurate mass and analytical retention time (AMRT) libraries to correctly identify known components and characterize unknown components. This rigor allows us to apply multivariate statistical software to evaluate the chemical basis of wine organoleptic properties. The use of multivariate software is becoming more prevalent in food and flavor laboratories as scientists work to understand how individual compounds combine to create a specific odor or taste. It is important to correctly identify compounds to build accurate statistical models that are capable of differential analysis. To this effect, we have constructed the accurate mass GC/Q-TOF library that currently contains about 400 flavor compounds. The core of the library is comprised of the wine volatiles with added pyrazines, furanones, and lactones to give it broader appeal. We have also applied the METLIN metabolic workflows in order to properly characterize yeast and grape metabolites. We then used multivariate statistics to correlate secondary metabolites with their organoleptic properties and terroir. Preliminary Results All the major volatile components are present and surprisingly consistent. The esters such as isoamyl acetate, ethyl hexanoate, ethyl octanoate that give wine sweet, fruity characteristics are abundantly present. Monoterpenes found at lower concentrations such as limonene, α-terpineol, citronellol, and nerol add citrus, green, woody and floral notes. Although not in the targeted flavor library, several interesting components gave good NIST library matches and were annotated. For example, vitispirane is an expected norisoprenoid which lends a pleasant earthy flavor to a wine. On the other hand, expected organoleptics with low odor thresholds such as methoxypyrazines, γ-lactones, and thiols are typically found at concentrations below the detection limit of GC/TOF and GC/QTOF instruments. The LC/QTOF data was searched against the METLIN and Vitis Vineferea databases. The more targeted Vitis Vinefera database clearly showed that flavonoids were differentially expressed in the costal and valley wines.

Revealing the chemical basis of organoleptic properties of a Cabernet Sauvignon wine using global LC and GC/QTOF workflows

252nd National Meeting (2016)

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