title: Factors affecting acetic acid production by yeasts in strongly clarified grape musts.
abstract: High acetate content in a wine, after strong clarification of the must, is due to depletion in the yeast cells of important metabolites (normally present in non-clarified musts) such as metals, amino acids, polyphenolic compounds and unsaturated fatty acids. These substances were added separately to a synthetic medium, comparable in composition to the clarified must, which was then inoculated with a high acetate producer strain. No effects were observed after the addition of various metals and amino acids. The addition of unsaturated fatty acids (Tween 80) caused a significant (p = 0.01) decrease in acetate content. Similar results have been obtained in the presence of polyphenols (catechins and anthocyans): their mechanism of action is probably due to direct inhibition of the enzyme aldehyde dehydrogenase. Control experiments were performed with a low acetate producer strain, and a reduction in acetate content was detected. No differences in the glyceropyruvic metabolism of the two strains was evident.
authors.affiliation: Istituto Sperimentale per l'Enologia, Asti, Italy.
authors.forename: E G
authors.initials: EG
authors.lastname: Moruno
authors.forename: C
authors.initials: C
authors.lastname: Delfini
authors.forename: E
authors.initials: E
authors.lastname: Pessione
authors.forename: C
authors.initials: C
authors.lastname: Giunta
mesh_terms: D000085:Acetates / Q000378:metabolism*; D019342:Acetic Acid; D003470:Culture Media / Q000737:chemistry; D005231:Fatty Acids, Unsaturated / Q000494:pharmacology*; D005285:Fermentation; D005419:Flavonoids; D005638:Fruit; D008670:Metals / Q000494:pharmacology*; D010636:Phenols / Q000494:pharmacology*; D011108:Polymers / Q000494:pharmacology*; D059808:Polyphenols; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D014920:Wine / Q000032:analysis*
chemical_list: D000085:Acetates; D003470:Culture Media; D005231:Fatty Acids, Unsaturated; D005419:Flavonoids; D008670:Metals; D010636:Phenols; D011108:Polymers; D059808:Polyphenols; D019342:Acetic Acid