title: Effect of yeast strain and some nutritional factors on tannin composition and potential astringency of model wines.
abstract: Nine Saccharomyces cerevisiae cultures, isolated from different sources, were tested for their ability to reduce tannins reactive towards salivary proteins, and potentially responsible for wine astringency. Strains were preliminary genetically characterized and evaluated for physiological features of technological interest. Laboratory-scale fermentations were performed in three synthetic media: CT) containing enological grape tannin; CTP) CT supplemented with organic nitrogen sources; CTPV) CTP supplemented with vitamins. Adsorption of total tannins, tannins reactive towards salivary proteins, yellow pigments, phenolics having antioxidant activity, and total phenols, characterizing the enological tannin, was determined by spectrophotometric methods after fermentation. The presence of vitamins and peptones in musts greatly influenced the adsorption of tannins reactive towards salivary proteins (4.24 g/L gallic acid equivalent), thus promoting the reduction of the potential astringency of model wines. With reference to the different phenolic classes, yeast strains showed different adsorption abilities. From a technological point of view, the yeast choice proved to be crucial in determining changes in gustative and mouthfeel profile of red wines and may assist winemakers to modulate colour and astringency of wine.
authors.affiliation: Università degli Studi di Napoli Federico II, Dipartimento di Agraria, Sezione di Scienze della Vigna e del Vino, Viale Italia, angolo Via Perrottelli, 83100, Avellino, Italy; Biolaffort, 126 Quai de la Souys, 33100, Bordeaux, France. Electronic address: alessandra.rinaldi@unina.it.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Rinaldi
authors.affiliation: Università degli Studi di Napoli Federico II, Dipartimento di Agraria, Sezione di Scienze della Vigna e del Vino, Viale Italia, angolo Via Perrottelli, 83100, Avellino, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Blaiotta
authors.affiliation: Università degli Studi di Napoli Federico II, Dipartimento di Agraria, Sezione di Microbiologia, Via Università 100, 80055, Portici, NA, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Aponte
authors.affiliation: Università degli Studi di Napoli Federico II, Dipartimento di Agraria, Sezione di Scienze della Vigna e del Vino, Viale Italia, angolo Via Perrottelli, 83100, Avellino, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Moio
mesh_terms: D003116:Color; D005285:Fermentation; D006801:Humans; D010636:Phenols / Q000378:metabolism; D013634:Tannins / Q000737:chemistry* / Q000378:metabolism; D013649:Taste; D027843:Vitis / Q000737:chemistry / Q000382:microbiology; D014920:Wine / Q000032:analysis / Q000382:microbiology*; D015003:Yeasts / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D010636:Phenols; D013634:Tannins
keywords: Adsorption; Astringency; Fermentation; Saliva; Tannin; Yeast