Determination of Volatile Phenol in Cabernet Sauvignon Wines, Made from Smoke-affected Grapes, by using HS-SPME GC-MS

  • C.J. de Vries Department of Viticulture and Oenology, Stellenbosch University
  • L.M. Mokwena Central Analytical Facility (CAF), Stellenbosch University
  • A. Buica Department of Viticulture and Oenology, Stellenbosch University
  • M. McKay Department of Viticulture and Oenology, Stellenbosch University


The increased incidence of vegetation fires near vineyards in the Western Cape, South Africa has led to
growing concern over the appearance of smoke taint in the affected grapes. This study focused on the
effect of smoke exposure on the volatile phenol (VP) composition of wines made from affected grapes
over two vintages (2012 and 2013). Cabernet Sauvignon grapes were exposed, 10 days post-véraison,
to a single, hour-long treatment with smoke derived from burning a mixture of vegetation (including
fynbos) under controlled conditions in enclosures. Enclosures were sealed for 24 h after exposure, and
then removed. Grapes were allowed to ripen and wines were then produced. Wines were analysed by
headspace gas chromatography mass spectrometry (HS-SPME GC-MS) for selected volatiles. The results
of the investigation show that the exposure of grapes to smoke during ripening leads to the accumulation of
VPs that were detected in wines. The detected VPs were guaiacol, phenol and the cresols. Smoke exposure
of grapes during ripening may have a negative impact on wine quality due to the accumulation of these