title: Effect of organic acids and nitrogen source on alcoholic fermentation: study of their buffering capacity.
abstract: The effect of tartaric acid and other organic acids on alcoholic fermentation was studied. Organic acids in media with high sugar concentrations and ammonium as the sole nitrogen source had an enormous impact on Saccharomyces cerevisiae metabolism during alcoholic fermentation. The main effect on yeast metabolism was the quick acidification of the media in the absence of organic acids. All of the organic acids used in this study (tartaric, malic, citric, and succinic acids) showed a buffering capacity, but not all of the acids had the same one. However, the results suggested that buffering should not be considered the only effect of organic acids on yeast metabolism. Nitrogen source also had a great influence on media pH. Ammonium consumption by yeasts produced a greater acidification of the media than when amino acids were used.
authors.affiliation: Unitat d'Enologia del Centre de Referència de Tecnologia d'Aliments, Departamento Bioquímica i Biotecnologia, Facultat d'Enologia de Tarragona, Universitat Rovira i Virgili, Ramón y Cajal 70, 43005 Tarragona, Spain.
authors.forename: María Jesús
authors.initials: MJ
authors.lastname: Torija
authors.forename: Gemma
authors.initials: G
authors.lastname: Beltran
authors.forename: Maite
authors.initials: M
authors.lastname: Novo
authors.forename: Montse
authors.initials: M
authors.lastname: Poblet
authors.forename: Nicolas
authors.initials: N
authors.lastname: Rozès
authors.forename: Albert
authors.initials: A
authors.lastname: Mas
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Guillamón
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000645:Ammonium Sulfate / Q000378:metabolism; D002021:Buffers; D019343:Citric Acid / Q000494:pharmacology; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008293:Malates / Q000494:pharmacology; D009584:Nitrogen / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D019802:Succinic Acid / Q000494:pharmacology; D013644:Tartrates / Q000494:pharmacology*; D014920:Wine / Q000032:analysis
chemical_list: D000596:Amino Acids; D002021:Buffers; D008293:Malates; D013644:Tartrates; D019343:Citric Acid; C030298:malic acid; D019802:Succinic Acid; D009584:Nitrogen; D000645:Ammonium Sulfate; C029768:tartaric acid