Statistical Evaluation of 4-ethylphenol and 4-ethylguaiacol Concentrations to Support Sensory Evaluation of "Brett Character" of Wines: A Proposed Threshold

  • Zsolt Csikor Department of Chemical and Environmental Process Engineering, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, H-1521 Budapest, P.O. Box 91, Hungary https://orcid.org/0000-0001-6543-8490
  • Éva Pusztai Department of Chemical and Environmental Process Engineering, Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, H-1521 Budapest, P.O. Box 91, Hungary https://orcid.org/0000-0002-1997-2630
  • Gábor Barátossy Directorate of Oenology and Alcoholic Beverages, National Food Chain Safety Office, H-1118 Budapest, Budaörsi út 141-145., Hungary

Abstract

nalytical data of 260 sensory evaluated wine samples have been statistically examined. All samples had been classified by at least one taster of the five member jury as having "Brett character". Wines have been finally judged as "Good", having "Other defects" or "Brett character". 4-etylphenol (4-EP) and 4-ethylguaiacol (4-EG) concentrations showed different distributions for the "Brett character" group while the other two groups could not be distinguished from each-other. Threshold concentrations for 4-EP, 4-EG and their sum (4-EP + 4-EG) were calculated to classify wine samples as "non-Brett" and "Brett character". 4-EP concentrations were found to be the most reliable markers, with a 245 µg/l lower and 968 µg/l upper threshold. Below or above this range a sample can reliably be classified as "non-Brett" and "Brett character" respectively, while within this range only sensory evaluation can distinguish the two characteristics. Other tested classical analytical parameters did not show significant differences between these groups except for SO2 which was found to be lower in the "Brett character" group, stressing the importance of sulpihiting as a tool in the fight against Brettanomyces.

Keywords: 4-ethylphenol, 4- ethylguaiacol, Brettanomyces, sensory evaluation, threshold
Published online
2018-10-13
How to Cite
Csikor, Z., Pusztai, Éva and Barátossy, G. (2018) “Statistical Evaluation of 4-ethylphenol and 4-ethylguaiacol Concentrations to Support Sensory Evaluation of "Brett Character" of Wines: A Proposed Threshold”, Periodica Polytechnica Chemical Engineering, 62(4), pp. 450–456. doi: https://doi.org/10.3311/PPch.12857.
Section
Articles