Abstract:
Phenolic and antioxidant contents of wines are very important in terms of both flavour attributes
and health benefits. Changes occur during ageing of wine in containers (e.g. wooden barrels) in
relation to their antioxidant activity and phenolic content. Vilana, Dafni, Kotsifali and Mandilari
single variety Cretan wines, were vinificated to determine their antioxidant activity and phenolic
content Wines were aged in different containers after two vinifications. Changes in the above
characteristics were determined every three months for a twelve month period. Stainless steel
with and without oenosticks containers, American oak, French oak, Acacia and Chestnut barrels
were used for wine ageing.
As far as phenolic and antioxidant contents are concerned, ageing of wine in chestnut barrels,
Kotsifali and Mandilari (red wines) and in Acacia barrels for Vilana and Dafni (white wines),
gave the best results, achieving the highest phenolic content and antioxidant activity after 12
months of ageing.
The phenolic fingerprints of Vilana, Dafni, Kotsifali and Mandilari wines were determined for
the first time. The phenolic fingerprint of wines has been recently used for the authentication
and discrimination of red wines. In this study, attempt has also been made to use the phenolic
fingerprint of white wines, for authentication. Differences were observed in Kotsifali and
Mandilari (red wines) and in Vilana and Dafni (white wines) directly after vinification, allowing
their discrimination. Also the changes in their phenolic fingerprints were monitored during
ageing in different containers for a 12 month period.
The effect of hydroxytyrosol and oleuropein on wine spoilage induced by acetic acid bacteria
was also determined. Hydroxytyrosol was better than oleuropein in controlling the increase of
volatile acidity, causing wine spoilage. Wines treated with 0.5mg/l hydroxytyrosol showed
control of volatile acid production, and may be a promising alternative to sulphites in wine
production in the future.
Finally, extracts obtained from olive oil mills and winery by-products were used in Vilana
vinification instead of sulphites and antioxidant activity and phenolic content of the wines
determined.
