| Title: | Accumulation of volatile phenol glycoconjugates in grapes following grapevine exposure to smoke and potential mitigation of smoke taint by foliar application of kaolin |
| Author(s): | van der Hulst L; Munguia P; Culbert JA; Ford CM; Burton RA; Wilkinson KL; |
| Address: | "School of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia. The ARC Training Centre for Innovative Wine Production, PMB 1, Glen Osmond, SA, 5064, Australia. School of Biological Sciences, The University of Adelaide, Adelaide, SA, 5005, Australia. Royal Melbourne Institute of Technology University, Melbourne, VIC, 3000, Australia. The Australian Wine Research Institute, PO Box 197, Glen Osmond, SA, 5064, Australia. The ARC Centre of Excellence in Plant Cell Walls, PMB 1, Glen Osmond, SA, 5064, Australia. School of Agriculture, Food and Wine, The University of Adelaide, PMB 1, Glen Osmond, SA, 5064, Australia. kerry.wilkinson@adelaide.edu.au. The ARC Training Centre for Innovative Wine Production, PMB 1, Glen Osmond, SA, 5064, Australia. kerry.wilkinson@adelaide.edu.au" |
| DOI: | 10.1007/s00425-018-03079-x |
| ISSN/ISBN: | 1432-2048 (Electronic) 0032-0935 (Linking) |
| Abstract: | "The accumulation of volatile phenol glycoconjugates in smoke-exposed grapes was monitored following grapevine exposure to smoke, with different glycoconjugate profiles observed for fruit sampled 1 and 7 days after smoke exposure, and at maturity. Foliar application of kaolin reduced the concentration of volatile phenol glycoconjugates in smoke-exposed fruit, but efficacy depended on the rate of application and extent of coverage. Smoke taint can be found in wines made from grapes exposed to smoke from bushfires or prescribed burns. It is characterized by objectionable smoky and ashy aromas and flavors, which have been attributed to the presence of smoke-derived volatile phenols, in free and glycoconjugate forms. This study investigated: (1) the accumulation of volatile phenol glycoconjugates in grapes following the application of smoke to Sauvignon Blanc, Chardonnay and Merlot grapevines at approximately 10 days post-veraison; and (2) the potential mitigation of smoke taint as a consequence of foliar applications of kaolin (a clay-based protective film) prior to grapevine smoke exposure. Varietal differences were observed in the glycoconjugate profiles of smoke-exposed grapes; the highest glycoconjugate levels were found in Merlot grapes, being pentose-glucosides of guaiacol, cresols, and phenol, and gentiobiosides of guaiacol and syringol. Changes in volatile phenol glycoconjugate profiles were also observed with time, i.e., between fruit sampled 1 day after smoke exposure and at maturity. The application of kaolin did not significantly affect the glycoconjugate profiles of Sauvignon Blanc and Chardonnay grapes, but significantly lower volatile phenol glycoconjugate levels were observed in Merlot fruit that was treated with kaolin prior to smoke exposure. The potential for control and smoke-exposed grapes to be differentiated by measurement of spectral reflectance was also demonstrated" |
| Keywords: | Fruit/chemistry/*drug effects/metabolism Gas Chromatography-Mass Spectrometry Glycoconjugates/*metabolism Kaolin/*pharmacology Phenols/*metabolism Plant Leaves/*drug effects/metabolism Smoke/adverse effects Spectrum Analysis Vitis/chemistry/*drug effects/; |
| Notes: | "Medlinevan der Hulst, Lieke Munguia, Pablo Culbert, Julie A Ford, Christopher M Burton, Rachel A Wilkinson, Kerry L eng IC130100005/Training Centre for Innovative Wine Production, Australian Research Council (AU)/ GWR Ph1403/Wine Australia/ Germany 2019/01/07 Planta. 2019 Mar; 249(3):941-952. doi: 10.1007/s00425-018-03079-x. Epub 2019 Jan 5" |
