title: Pre-fermentation addition of grape tannin increases the varietal thiols content in wine.
abstract: The recent finding that grape tannin may contain significant amount of S-glutathionylated (GSH-3MH) and S-cysteinylated (Cys-3MH) precursors of the varietal thiols 3-mercapto-1-hexanol and 3-mercaptohexyl acetate, characteristic of Sauvignon blanc wines, offers new opportunities for enhancing the tropical aroma in fermented beverages. In this study this new hypothesis was investigated: Müller Thurgau (17 samples) and Sauvignon blanc (15 samples) grapes were fermented with and without addition of a selected grape tannin. As expected, the tannin-added juices were higher in precursors, and they produced wines with increased free thiols. Preliminary informal sensory tests confirmed that in particular the Sauvignon wines produced with the tannin addition were often richer with increased "fruity/green" notes than the corresponding reference wines. This outcome confirms that grape tannin addition prior to fermentation can fortify the level of these compounds.
authors: FEM-IASMA Fondazione Edmund Mach - Istituto Agrario di San Michele all'Adige, via E. Mach 1, 38010 San Michele all'Adige (TN), Italy. Electronic address: roberto.larcher@fmach.it.
authors: Roberto
authors: R
authors: Larcher
authors: FEM-IASMA Fondazione Edmund Mach - Istituto Agrario di San Michele all'Adige, via E. Mach 1, 38010 San Michele all'Adige (TN), Italy.
authors: Loris
authors: L
authors: Tonidandel
authors: FEM-IASMA Fondazione Edmund Mach - Istituto Agrario di San Michele all'Adige, via E. Mach 1, 38010 San Michele all'Adige (TN), Italy.
authors: Tomás
authors: T
authors: Román Villegas
authors: FEM-IASMA Fondazione Edmund Mach - Istituto Agrario di San Michele all'Adige, via E. Mach 1, 38010 San Michele all'Adige (TN), Italy.
authors: Tiziana
authors: T
authors: Nardin
authors: Wine Science Programme, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
authors: Bruno
authors: B
authors: Fedrizzi
authors: FEM-IASMA Fondazione Edmund Mach - Istituto Agrario di San Michele all'Adige, via E. Mach 1, 38010 San Michele all'Adige (TN), Italy.
authors: Giorgio
authors: G
authors: Nicolini
mesh_terms: D000085:Acetates / Q000737:chemistry*; D005285:Fermentation; D005638:Fruit / Q000737:chemistry; D006801:Humans; D013438:Sulfhydryl Compounds / Q000032:analysis* / Q000737:chemistry; D013634:Tannins / Q000737:chemistry*; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*
chemical_list: D000085:Acetates; D013438:Sulfhydryl Compounds; D013634:Tannins; C513640:3-mercaptohexyl acetate
keywords: 3-Mercapto-1-hexanol; 3-Mercaptohexyl acetate; Grape tannin; Wine