title: Inactive dry yeast application on grapes modify Sauvignon Blanc wine aroma.
abstract: This study investigated the potential to improve wine aroma by applying two inactive dry yeast products (IDYs) at the onset of ripening on Sauvignon Blanc grapes. Both products led to increased reduced glutathione concentrations in the grape juice and corresponding wines, as well as differences in individual higher alcohol acetates (HAAs) and ethyl esters of straight chain fatty acids (EEFAs) at the end of fermentation. After two months of storage, a significantly slower decrease of EEFAs and to a lesser extent of HAAs was found for wines made from grapes with IDY applications. These wines also resulted in significantly slower synthesis of ethyl esters of branched acids, whereas varietal thiols were altered in a product-specific manner. The modifications in the wine chemical composition were also sensorially corroborated. This study showed that vineyard additions of IDY products directly on the grapes at the onset of ripening have a subsequent benefit to the production and preservation of aroma in wines.
authors.affiliation: Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, PO Box X1, Matieland, Stellenbosch 7602, South Africa.
authors.forename: Katja
authors.initials: K
authors.lastname: Šuklje
authors.affiliation: Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, PO Box X1, Matieland, Stellenbosch 7602, South Africa.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Antalick
authors.affiliation: Department of Viticulture and Oenology, Stellenbosch University, PO Box X1, Matieland, Stellenbosch 7602, South Africa.
authors.forename: Astrid
authors.initials: A
authors.lastname: Buica
authors.affiliation: Department of Viticulture and Oenology, Stellenbosch University, PO Box X1, Matieland, Stellenbosch 7602, South Africa.
authors.forename: Zelmari A
authors.initials: ZA
authors.lastname: Coetzee
authors.affiliation: Department of Viticulture and Oenology, Stellenbosch University, PO Box X1, Matieland, Stellenbosch 7602, South Africa.
authors.forename: Jeanne
authors.initials: J
authors.lastname: Brand
authors.affiliation: National Wine and Grape Industry Centre, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia; School of Agricultural and Wine Science, Charles Sturt University, Locked Bag 588, Wagga Wagga, NSW 2678, Australia.
authors.forename: Leigh M
authors.initials: LM
authors.lastname: Schmidtke
authors.affiliation: Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, PO Box X1, Matieland, Stellenbosch 7602, South Africa. Electronic address: mav@sun.ac.za.
authors.forename: Melané A
authors.initials: MA
authors.lastname: Vivier
mesh_terms: D000085:Acetates / Q000032:analysis; D004952:Esters / Q000032:analysis; D005285:Fermentation; D005511:Food Handling / Q000379:methods*; D063427:Food Quality; D012441:Saccharomyces cerevisiae; D012903:Smell; D013438:Sulfhydryl Compounds / Q000032:analysis; D027843:Vitis / Q000737:chemistry*; D014920:Wine / Q000032:analysis*; D015002:Yeast, Dried
chemical_list: D000085:Acetates; D004952:Esters; D013438:Sulfhydryl Compounds
keywords: Esters; Fermentation; Glutathione; Inactive dry yeast; Sensory analysis; Thiols