title: Outlining a selection procedure for Saccharomyces cerevisiae isolated from grape marc to improve fermentation process and distillate quality.
abstract: Nowadays grape marc represents one of the main by-product of winemaking. Many South Europe countries valorize this ligno-cellulosic waste through fermentation and distillation for industrial alcoholic beverage production. The storage of marcs is a crucial phase in the distillation process, due to the physicochemical transformations ascribed to microbial activity. Among the methods adopted by distillers to improve the quality of spirits, the use of selected yeasts has not been explored so far, therefore in this work we evaluated the selection criteria of Saccharomyces cerevisiae strains for grape marc fermentation. The proposed selection procedure included three steps: characterization of phenotypical traits, evaluation of selected strains on pasteurised grape marc at lab-scale (100 g) and pilot-scale fermentation (350 kg). This selection process was applied on 104 strains isolated from grape marcs of different origins and technological treatment. Among physiological traits, β-glucosidase activity level as quality trait seems to be only partially involved in increasing varietal flavour. More effective in describing yeast impact on distillate quality is the ratio higher alcohols/esters that indicates strain ability to increase positive flavours. Finally, evaluating grape marc as source of selected yeasts, industrial treatment rather than varietal origin seems to shape strain technological and quality traits.
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse naturali e Ambiente, Università degli Studi di Padova, Legnaro PD, Italy.
authors.forename: Barbara
authors.initials: B
authors.lastname: Bovo
authors.affiliation: Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia (C.I.R.V.E.), Università degli Studi di Padova, Conegliano TV, Italy.
authors.forename: Milena
authors.initials: M
authors.lastname: Carlot
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse naturali e Ambiente, Università degli Studi di Padova, Legnaro PD, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Fontana
authors.affiliation: Istituto per la Qualità e le Tecnologie Agroalimentari, Veneto Agricoltura, Thiene VI, Italy.
authors.forename: Angiolella
authors.initials: A
authors.lastname: Lombardi
authors.affiliation: Centro Regionale per la Viticoltura l'Enologia e la Grappa (CeRVEG), Conegliano TV, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Soligo
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse naturali e Ambiente, Università degli Studi di Padova, Legnaro PD, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia (C.I.R.V.E.), Università degli Studi di Padova, Conegliano TV, Italy. Electronic address: alessio.giacomini@unipd.it.
authors.forename: Alessio
authors.initials: A
authors.lastname: Giacomini
authors.affiliation: Dipartimento di Agronomia Animali Alimenti Risorse naturali e Ambiente, Università degli Studi di Padova, Legnaro PD, Italy; Centro Interdipartimentale per la Ricerca in Viticoltura ed Enologia (C.I.R.V.E.), Università degli Studi di Padova, Conegliano TV, Italy.
authors.forename: Viviana
authors.initials: V
authors.lastname: Corich
mesh_terms: D057168:Distillation; D005285:Fermentation; D005516:Food Microbiology / Q000379:methods*; D006801:Humans; D012441:Saccharomyces cerevisiae / Q000302:isolation & purification* / Q000378:metabolism; D013649:Taste; D027843:Vitis / Q000378:metabolism / Q000382:microbiology*; D014920:Wine / Q000032:analysis* / Q000382:microbiology
keywords: Biodiversity; By-product; GC/MS analysis; Higher alcohols; mtDNA-RFLP