| Title: | Glycosidically-Bound Volatile Phenols Linked to Smoke Taint: Stability during Fermentation with Different Yeasts and in Finished Wine |
| Author(s): | Whitmore BA; McCann SE; Noestheden M; Dennis EG; Lyons SM; Durall DM; Zandberg WF; |
| Address: | "Department of Biology, The University of British Columbia, 1177 Research Road, Kelowna, BC V1V 1V7, Canada. Department of Chemistry, The University of British Columbia, 3247 University Way, Kelowna, BC V1V 1V7, Canada" |
| DOI: | 10.3390/molecules26154519 |
| ISSN/ISBN: | 1420-3049 (Electronic) 1420-3049 (Linking) |
| Abstract: | "When wine grapes are exposed to smoke, there is a risk that the resulting wines may possess smoky, ashy, or burnt aromas, a wine flaw known as smoke taint. Smoke taint occurs when the volatile phenols (VPs) largely responsible for the aroma of smoke are transformed in grape into a range of glycosides that are imperceptible by smell. The majority of VP-glycosides described to date are disaccharides possessing a reducing beta-d-glucopyranosyl moiety. Here, a two-part experiment was performed to (1) assess the stability of 11 synthesized VP-glycosides towards general acid-catalyzed hydrolysis during aging, and (2) to examine whether yeast strains differed in their capacity to produce free VPs both from these model glycosides as well as from grapes that had been deliberately exposed to smoke. When fortified into both model and real wine matrices at 200 ng/g, all VP-disaccharides were stable over 12 weeks, while (42-50 ng/g) increases in free 4-ethylphenol and p-cresol were detected when these were added to wine as their monoglucosides. Guaiacol and phenol were the most abundantly produced VPs during fermentation, whether originating from natural VP-precursors in smoked-exposed Pinot Noir must, or due to fortification with synthetic VP-glycosides. Significant yeast strain-specific differences in glycolytic activities were observed for phenyl-beta-d-glycopyranoside, with two strains (RC212 and BM45) being unable to hydrolyze this model VP, albeit both were active on the guaiacyl analogue. Thus, differences in Saccharomyces cerevisiae beta-glucosidase activity appear to be influenced by the VP moiety" |
| Keywords: | Cresols/metabolism *Fermentation Fruit/*metabolism Glycosides/*metabolism Guaiacol/metabolism Odorants/*analysis Phenol/*metabolism Phenols/metabolism Saccharomyces cerevisiae/*enzymology Smoke/*adverse effects Vitis/*metabolism Volatile Organic Compounds; |
| Notes: | "MedlineWhitmore, Brandon A McCann, Stephanie E Noestheden, Matthew Dennis, Eric G Lyons, Sarah M Durall, Daniel M Zandberg, Wesley F eng 35246/Canada Foundation for Innovation/ 35246/BC Knowledge Development Fund/ Eminence Fund/The University of British Columbia (Okanagan Campus)/ Switzerland 2021/08/08 Molecules. 2021 Jul 27; 26(15):4519. doi: 10.3390/molecules26154519" |
