title: Identification of a beta-D-glucopyranoside precursor to guaiacol in grape juice following grapevine exposure to smoke.
abstract: The presence of the beta-D-glucopyranoside of guaiacol (glucoside) in juice of grapes following grapevine exposure to smoke was investigated. The glucoside was synthesized as a reference compound and an HPLC-MS/MS method was developed for its detection in juice. The glucoside was found in the juice extracts of grapes exposed to bushfire smoke, as well as grapes experimentally exposed to smoke. Compared to the control (unsmoked) juice sample, the experimentally smoked juice contained a significant amount of the glucoside, indicating glucosylation of guaiacol occurred following grapevine smoke exposure. The reference compound, and the glucoside found in the smoked juice samples were less susceptible to acid treatment but virtually disappeared after enzyme treatment with beta-glucosidase. The susceptibility of the glucoside to enzyme hydrolysis could be one reason for the release of guaiacol from smoke affected grapes during fermentation.
authors.affiliation: The Australian Wine Research Institute, PO Box 197, Glen Osmond, SA 5064, Australia. yoji.hayasaka@awri.com.au
authors.forename: Y
authors.initials: Y
authors.lastname: Hayasaka
authors.forename: K A
authors.initials: KA
authors.lastname: Dungey
authors.forename: G A
authors.initials: GA
authors.lastname: Baldock
authors.forename: K R
authors.initials: KR
authors.lastname: Kennison
authors.forename: K L
authors.initials: KL
authors.lastname: Wilkinson
mesh_terms: D001628:Beverages / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005960:Glucosides / Q000032:analysis*; D006139:Guaiacol / Q000032:analysis / Q000737:chemistry*; D006868:Hydrolysis; D012906:Smoke; D053719:Tandem Mass Spectrometry / Q000379:methods*; D027843:Vitis / Q000737:chemistry*; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D005960:Glucosides; D012906:Smoke; D006139:Guaiacol; D001617:beta-Glucosidase