Smoke-derived taint in wine: the release of smoke-derived volatile phenols during fermentation of Merlot juice following grapevine exposure to smoke

J Agric Food Chem. 2008 Aug 27;56(16):7379-83. doi: 10.1021/jf800927e. Epub 2008 Aug 5.


The release of smoke-derived volatile phenols during the fermentation of Merlot grapes, following grapevine exposure to smoke, has been investigated. The concentrations of guaiacol, 4-methylguaiacol, 4-ethylguaiacol, 4-ethylphenol, and eugenol were determined by gas chromatography-mass spectrometry and found to increase throughout the winemaking process. Only trace levels (< or = 1 microg/L) of guaiacol and 4-methylguaiacol could be detected in free run juice derived from the fruit of smoked vines; the highest levels, 388 microg/L and 93 microg/L, respectively, were observed in the finished wine. Control wine (derived from fruit of unsmoked vines) contained 4 microg/L guaiacol, with the volatile phenols either not detected or detected at only trace levels (< or = 1 microg/L) throughout fermentation. The role of enzyme and acid catalyzed hydrolysis reactions in releasing smoke-derived volatile compounds was also investigated. The volatile phenols were released from smoked free run juice by strong acid hydrolysis (pH 1.0) and enzyme (beta-glucosidase) hydrolysis, but not mild acid hydrolysis (juice pH 3.2-3.7). Guaiacol was again the most abundant smoke-derived phenol, present at 431 microg/L and 325 microg/L in strong acid and enzyme hydrolysates, respectively. Only trace levels of each phenol could be detected in each control hydrolysate. This study demonstrates the potential for under-estimation of smoke taint in fruit and juice samples; the implications for the assessment of smoke taint and quantification of volatile phenols are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Eugenol / analysis
  • Fermentation
  • Fruit / chemistry
  • Fruit / growth & development
  • Guaiacol / analysis
  • Hydrolysis
  • Odorants / analysis*
  • Phenols / analysis*
  • Smoke / analysis*
  • Vitis / growth & development*
  • Wine / analysis*


  • Phenols
  • Smoke
  • Eugenol
  • Guaiacol