| Autor: |
Dykes, Stuart, Kilmartin, Paul |
| Zdroj: |
Australian & New Zealand Wine Industry Journal; Sep2007, Vol. 22 Issue 5, p31-45, 11p, 4 Diagrams, 5 Charts, 9 Graphs |
| Abstrakt: |
Micro-oxygenation is a process that reduces the requirement for wooden barrels thus conferring considerable direct and indirect cost savings. To fully realise the commercial potential of micro-oxygenation, however, a better understanding is required of the entire process. Three discrete trials are presented in this paper. The first investigates the chemical and sensory transformations that occur in a wine undergoing micro-oxygenation at different oxygen dosage rates. Both the sensory and HPLC data suggest that an increase in dosage rate accelerates the development of the wine. It remains to be determined at what rate the wine begins to deteriorate. The second trial investigated the effect of sulphur dioxide on the tannin development as measured by colourmetric and thiolysis assays. The results indicate that sulphur dioxide effectively retards the condensation of tannins, presumably through the nucleophilic addition of the bisulphite ion on the flavanyl-4-carbocation of a hydrolysed flavanoid terminal unit. The timing of the sulphur addition is therefore critical while the wine is undergoing treatment. Moreover the results suggest that the effectiveness of any micro-oxygenation after the addition of sulphur-dioxide is questionable. Finally some modelling work is presented that allows a better understanding of the micro-oxygenation process, specifically the marked effects of yeast lees on the oxygen consumption kinetics of a wine and the relationship between bubble size and oxygenation efficiency. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
|
