Natural Product Phenolic Diglycosides Created from Wildfires, Defining Their Impact on California and Oregon Grapes and Wines.

Forest fires produce malodorous phenols, bioaccumulated in grapes as odorless phenol glycosides (mono- to tri-), and produce unpleasant wines when these complexes are transformed by glycosidases in saliva. Metabolomic analyses were used to further understand by quantitating marker phenolic diglycosides via UHPLC separations and MS/MS multiple reaction monitoring. A collection of grapes and wines provided data to forecast wine quality of grapes subjected to wildfire smoke infestations; the analytics used a panel of reference compounds (-). Overall, eight different varietals were examined from 2017-2021 vintages involving >218 distinct samples (wines and/or grapes) from 21 different American Viticulture Areas. Results acquired allowed correlation of phenolic diglycoside levels as a function of grape cultivar, varietal clones, and intensity of wildfire smoke. Baseline data were tabulated for nonsmoked samples (especially, Cabernet Sauvignon having a sum - of <6 μg/L) and then compared to those exposed to six other levels of smoke. Outcomes established that (1) analyzing paired samples (bottled wines versus smoke-exposed grapes) can provide diagnostic metabolomic data, (2) phenolic diglycosides are stable in wines aged for >2.5 years, and (3) major gaps exist in our current understanding of this pool of metabolites.