title: Interactions between yeast autolysates and volatile compounds in wine and model solution.
abstract: The addition of a commercial yeast autolysate to a model solution of five typical wine aroma compounds (ethyl octanoate, linalool, 2-phenylethanol, β-ionone and octanoic acid) was investigated considering different variables, such as temperature, pH and the presence of highly concentrated natural volatile substances in wine (e.g. 3-methyl-1-butanol). The interactions of such compounds with both yeast walls and released colloids were studied using gas chromatography, with liquid-liquid extraction and solid-phase microextraction. The results were compared with those obtained by adding the commercial product to a white table wine, spiked with the five standard compounds. The data confirmed that yeast walls mainly bind less polar molecules: their loss in synthetic medium seemed to increase at higher pH values. Temperature and pH affected differently the interactions between yeast colloids and volatile compounds in wine and model solution: in complex solutions (as the addition of 3-methyl-1-butanol demonstrated) the interaction mechanisms could be influenced by competitive or other matrix-related effects, which can reduce the binding of single compounds, or even enhance their volatility.
authors.affiliation: Università degli Studi di Udine, Dipartimento di Scienze degli Alimenti, Sezione Industrie Agrarie, via Sondrio, 2/A, 33100 Udine, Italy. Electronic address: piergiorgio.comuzzo@uniud.it.
authors.forename: Piergiorgio
authors.initials: P
authors.lastname: Comuzzo
authors.forename: Lara
authors.initials: L
authors.lastname: Tat
authors.forename: Dennis
authors.initials: D
authors.lastname: Fenzi
authors.forename: Laura
authors.initials: L
authors.lastname: Brotto
authors.forename: Franco
authors.initials: F
authors.lastname: Battistutta
authors.forename: Roberto
authors.initials: R
authors.lastname: Zironi