title: Discrimination of sweet wines partially fermented by two osmo-ethanol-tolerant yeasts by gas chromatographic analysis and electronic nose.
abstract: Some special sweet wines are obtained by partial fermentation of musts from off-vine dried grapes containing large amounts of sugars. This process is very slow and subject to serious stop problems that can be avoided by using osmo-ethanol-tolerant yeasts. Musts containing 371g/l of sugars were partially fermented with selected Saccharomyces cerevisiae strains, X4 and X5, to 12% (v/v) and the wines obtained with X5 exhibited a higher volatile acidity but lower concentrations of higher alcohols, carbonyl compounds and polyols than those obtained with X4. A principal component analysis (PCA) of the data provided by an electronic nose (E-nose) afforded discrimination between fermented and unfermented musts, but not between wines obtained with X4 or X5. The PCA applied to the major volatile compounds and polyols shows similar results, but a clear discrimination between wines is obtained by removing the polyols glycerol and 2,3-butanediol from the PCA.
authors.affiliation: Departamento de Microbiología, University of Córdoba, Spain.
authors.forename: Teresa
authors.initials: T
authors.lastname: García-Martínez
authors.affiliation: DISTA, Laboratorio Postraccolta, Tuscia University, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Bellincontro
authors.affiliation: Departamento de Química Agrícola y Edafología, University of Córdoba, Spain.
authors.forename: María de Las Nieves López
authors.initials: Mde L
authors.lastname: de Lerma
authors.affiliation: Departamento de Química Agrícola y Edafología, University of Córdoba, Spain.
authors.forename: Rafael Andrés
authors.initials: RA
authors.lastname: Peinado
authors.affiliation: Departamento de Microbiología, University of Córdoba, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Mauricio
authors.affiliation: DISTA, Laboratorio Postraccolta, Tuscia University, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Mencarelli
authors.affiliation: Departamento de Química Agrícola y Edafología, University of Córdoba, Spain. Electronic address: qe1movij@uco.es.
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Moreno
keywords: Electronic nose; Osmotolerant yeasts; Partial fermentation; Polyols; Sweet wine; Volatile compounds