title: Using mixed inocula of Saccharomyces cerevisiae killer strains to improve the quality of traditional sparkling-wine.
abstract: The quality of traditional sparkling-wine depends on the aging process in the presence of dead yeast cells. These cells undergo a slow autolysis process thereby releasing some compounds, mostly colloidal polymers such as polysaccharides and mannoproteins, which influence the wine's foam properties and mouthfeel. Saccharomyces cerevisiae killer yeasts were tested to increase cell death and autolysis during mixed-yeast-inoculated second fermentation and aging. These yeasts killed sensitive strains in killer plate assays done under conditions of low pH and temperature similar to those used in sparkling-wine making, although some strains showed a different killer behaviour during the second fermentation. The fast killer effect improved the foam quality and mouthfeel of the mixed-inoculated wines, while the slow killer effect gave small improvements over single-inoculated wines. The effect was faster under high-pressure than under low-pressure conditions. Wine quality improvement did not correlate with the polysaccharide, protein, mannan, or aromatic compound concentrations, suggesting that the mouthfeel and foaming quality of sparkling wine are very complex properties influenced by other wine compounds and their interactions, as well as probably by the specific chemical composition of a given wine.
authors.affiliation: Departamento de Ciencias Biomédicas (Área de Microbiología), Facultad de Ciencias, Universidad de Extremadura, 06071, Badajoz, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Velázquez
authors.affiliation: Estación Enológica, Junta de Extremadura, 06200, Almendralejo, Spain.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Zamora
authors.affiliation: Heral Enología, SL, C/Alfonso Iglesias Infante n(o) 11, 06200, Almendralejo, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Álvarez
authors.affiliation: Estación Enológica, Junta de Extremadura, 06200, Almendralejo, Spain.
authors.forename: María L
authors.initials: ML
authors.lastname: Álvarez
authors.affiliation: Departamento de Ciencias Biomédicas (Área de Microbiología), Facultad de Ciencias, Universidad de Extremadura, 06071, Badajoz, Spain. Electronic address: mramirez@unex.es.
authors.forename: Manuel
authors.initials: M
authors.lastname: Ramírez
mesh_terms: D000898:Antibiosis; D001433:Bacteriolysis; D005285:Fermentation; D005516:Food Microbiology; D007218:Industrial Microbiology; D010641:Phenotype; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000378:metabolism*; D014920:Wine / Q000032:analysis* / Q000382:microbiology* / Q000592:standards
keywords: Autolysis; Diethyl succinate (PubChem CID: 31249); Foam; Killer; Saccharomyces cerevisiae; Sparkling wine; Yeast; diethyl malate (PubChem CID: 24197); ethyl 2-methylbutanoate (PubChem CID: 24020); ethyl 4-hydroxybutanoate (PubChem CID: 357772); ethyl octanoate (PubChem CID: 7799); octanoic acid (PubChem CID: 379); γ-butyrolactone (PubChem CID: 7302)