Determination of odour detection threshold for α-guaiene in water highlights potential wine aroma contribution, especially for panellists who are anosmic to rotundone

• Published in: OENO one Vol. 59; no. 4
• Main Authors: Denat, Marie, Tempère, Sophie, Geffroy, Olivier
• Format: Journal Article
• Language: English
• Published: International Viticulture and Enology Society (IVES) 06.10.2025; International Viticulture and Enology Society
• Subjects: Environmental Sciences; individual thresholds; ISO 13301; rotundone; α-guaiene; ISO 13301; rotundone; α-guaiene; individual thresholds
• ISSN: 2494-1271; 2494-1271
• DOI: 10.20870/oeno-one.2025.59.4.9378

Rotundone is the main aroma compound responsible for peppery notes in wine. This work aimed to estimate orthonasal odour detection thresholds (ODTs) of rotundone and its precursor, α-guaiene, in water. For both compounds, ODTs were measured using a panel of 63 subjects and ten three-alternative forced-choice (3-AFC) tests, with concentrations ranging from 1 to 3814 ng/L and a step factor of 2.5 between each series. Unlike rotundone, which exhibited a bimodal distribution suggestive of a genetically driven specific anosmia or hyposmia, individual thresholds of α-guaiene followed a normal distribution. The absence of cross-anosmia between the two compounds suggests that α-guaiene may be perceived by individuals with reduced sensitivity to rotundone. Group detection threshold was determined for α-guaiene at 120 ng/L, a value slightly higher than that of rotundone (55 ng/L). Although preliminary, these findings highlight a potentially significant aromatic contribution of α-guaiene, opening a new field of investigation to determine its ODT in red wine and to evaluate its concentration range in this latter matrix.