Abstract
In the recent years, there is a great interest concerning the relation between wine pH and the
formation of turbidity in unfined white wines. Actually, a haze in bottled wine can reduce or
invalidate its commercial value, and winemakers typically perform fining treatments to avoid wine
turbidity. In the present study, the protein profile of the Erbaluce wine, one typical Italian white wine,
was analyzed in relation to the haze-forming tendency and pH variation. A pH range from 3.00–3.60
was obtained experimentally and the corresponding heat stability was analyzed. The results
indicated increased heat stability at lower pH, which was indicated by a lack of haze formation even
above 70°C. The increase in pH was accompanied by a progressive shift in the haze formation from
50–60°C to 70–80°C. The proteins extracted from the wine samples at different pHs were separated
by SDS-PAGE and identified by mass spectrometry analyses. Proteins derived from both yeast and
grape tissues were present in the wine extracts. The statistical analysis of band intensities revealed
that the solubility of certain yeast and grape proteins was modified by the pH shift. Interestingly,
most of the proteins were glycosylated inducing the hypothesis that the sugar chain may have an
influence on the differential solubility of wine proteins in response to pH. This finding could
encourage researchers to consider wine to be a more complex model fluid with respect to those
currently taken into account in wine heat stability studies.
Lingua originale | English |
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Titolo della pubblicazione ospite | Proceedings of the 7th International Conference on Chemical Reactions ion Foods VII |
Pagine | 201 |
Numero di pagine | 1 |
Stato di pubblicazione | Pubblicato - 2012 |
Evento | 7th International Conference on Chemical Reactions in Foods - Praga Durata: 14 nov 2012 → 16 nov 2012 |
Convegno
Convegno | 7th International Conference on Chemical Reactions in Foods |
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Città | Praga |
Periodo | 14/11/12 → 16/11/12 |
Keywords
- Glycoproteins
- Haze formation
- Heat stability
- Wine pH
- Wine proteins