Chelation of aqueous iron(III) by 2-acetyl-1,3-cyclohexanedione and beer ageing
2003
Blanco, Carlos A. | Caballero, Isabel | Rojas, Antonio | Gomez, Manuel | Alvarez, Javier
Fe(III) is present in alcoholic drinks, such as wine and beer, and it is well known that this metal ion may affect beer fermentation, stability and quality. From a study of the complexation of 2-acetyl-1,3-cyclohexanedione with Fe(III)in aqueous solution, thermodynamic and kinetic parameters were obtained. Kinetics and equilibria in aqueous 1:1 chelation were investigated spectrophotometrically in aqueous solution at 25 °C and ionic strength of 0.5 mol dm−3 NaClO4. The mechanism proposed to account for the kinetic data involves a double reversible pathway, where both Fe3+ and Fe(OH)2+ react with the enol tautomer of the ligand. Some comparative analyses with the homologous iron(III) 2-acetylcyclohexanonate were established and the effect of previously cited changes during beer ageing considered.
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