title: Reductive off-odors in wines: Formation and release of H₂S and methanethiol during the accelerated anoxic storage of wines.
abstract: In order to better understand the processes involved in the development of H2S and methanethiol (MeSH) along anoxic storage of wines, 24 wines were stored in strict anoxia at 50°C for 3weeks. Free and total forms of H2S and MeSH were measured at different times. Results showed that: (1) all wines contain relevant proportions of bonded forms of H2S and MeSH (93% and 47% on average); (2) such % decreases with age; (3) levels of total forms are related to wine metal composition; (4) anoxic storage brings about an increase of free forms, a strong decrease in the percentage of bonded forms, and except for H2S in red wines, an increase in total forms. Both de novo formation and release contribute to reductive off-odors. Release is predominant for reds and H2S, while at 50°C, de novo formation dominates for whites and rosés and MeSH.
authors.affiliation: Laboratory for Aroma Analysis and Enology, Instituto Agroalimentario de Aragón (IA2), Department of Analytical Chemistry, Faculty of Sciences, Universidad de Zaragoza, 50009 Zaragoza, Spain.
authors.forename: Ernesto
authors.initials: E
authors.lastname: Franco-Luesma
authors.affiliation: Laboratory for Aroma Analysis and Enology, Instituto Agroalimentario de Aragón (IA2), Department of Analytical Chemistry, Faculty of Sciences, Universidad de Zaragoza, 50009 Zaragoza, Spain. Electronic address: vferre@unizar.es.
authors.forename: Vicente
authors.initials: V
authors.lastname: Ferreira
mesh_terms: D061353:Food Storage; D006862:Hydrogen Sulfide / Q000032:analysis*; D009812:Odorants / Q000032:analysis*; D013438:Sulfhydryl Compounds / Q000032:analysis*; D014920:Wine / Q000032:analysis*
chemical_list: D013438:Sulfhydryl Compounds; C005231:methylmercaptan; D006862:Hydrogen Sulfide
keywords: Bonded H(2)S; Copper; De novo formation; Reduction; Sulfur; Wine aging