Identification and Sensory Evaluation of 3-Sulfanylhexyl Propionate and 3-Sulfanylhexyl Butyrate in Wine

Two new polyfunctional thiols, 3-sulfanylhexyl propionate (3SHP) and 3-sulfanylhexyl butyrate (3SHB), were detected in wines, synthesized as reference standards, and their sensory properties were characterized. Fermentations supplemented with short-chain fatty acids (propionic acid and butyric acid) generated 3SHP and 3SHB, which were confirmed by GC-MS using synthetic standards. Analysis of commercial wines from Scheurebe, Sauvignon blanc, and Verdejo further verified the presence of 3SHP and 3SHB, reporting their first identification in wines to our knowledge. To determine the influence of these esters on wine aroma, their odor threshold values (detection and recognition thresholds) were identified. Here, both compounds were described with grapefruit, passionfruit and tropical fruit descriptors. Although concentrations in many commercial samples were below sensory detection thresholds, synergistic sensory interactions with other polyfunctional thiols to the tropical wine aroma can be assumed.