| TAZ-TFG-2014-1046 |
Protocolización del análisis de aldehídos de oxidación en vinos españoles y su relación con diversos parámetros composicionales y de almacenamiento
Herrero Martín, Javier
Ferreira González, Vicente (dir.)
Universidad de Zaragoza,
CIEN,
2014
Química Analítica department, Química Analítica area
Graduado en Química
Free keyword(s): aldehídos ; oxidación ; cromatografía de gases
Tipo de Trabajo Académico: Trabajo Fin de Grado
Notas: Abstract Aldehydes and ketones are molecular groups with greatest sensory diversity in wine. Oxidative degradation associated with these compounds leads to a rapid loss of the aromatic qualities of the wine and the formation of other flavors that are associated with spoiled wine. It can be stated that the life of a wine ends when the aroma of certain carbonyls predominates over the rest. The analysis of these compounds presents a challenge, as they are very volatile and reactive, capable of forming strong interactions with other molecules, among which stands out SO2. Because of that, the determination of both free and bound forms of these compounds is crucial. This is achieved by using surrogate molecules, whose behavior is very similar to the analytes, and by analysis using a HS-SPME-GC-MS method. In order to ensure that the estimations are right the concentrations of the surrogates should be known accurately. As analytes, internal standards and surrogates can be degraded despite of the use of thorough preservation and manipulation measures, the shelf-life of working solutions with those families of compounds should be assessed. Consequently a solution with the compounds of interest was prepared and stored and used following thorough standard procedures along 75 days. The stability of the compounds in the solution was assessed by its analytical control, with a total of 32 measurements evenly distributed along the 75 days. Different plots of absolute or relative areas versus time were made and different statistical techniques were applied in order to assess the degradation rate of the different compounds. Compounds could be satisfactorily classified into four different groups of similar stabilities. The practical outcome of this work is the proposal of splitting mother solutions into the 4 different groups of stability (1 week, 2 weeks, 1 month, 2 months), minimizing experimental effort and preserving the method quality.
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