The effect of wine production stages to antioxidant structures of red wines that produced in Bozcaada

The study was carried on the red grape samples grown in Bozcaada and processed into wine with traditional methods. Samples of 2010 vintage season which were taken at determined stages of winemaking process (maceration, fermentation and 1st transfer) were studied to find their phenolic content and antioxidant capacity. The used grape varieties were Bozcaada originated Karalahna, Karasakız and came from abroad and started to grown in Bozcaada: Cabernet Sauvignon, Şiraz, Merlot, and Alicante Bouschet.In the study descriptive wine analyses: pH, titration acidity, brix, color hue and intensity, also the analyses to determine phenolic content: total tannin, total anthocyanin, total phenolic content (with Folin Ciocalteu method), total antioxidant capacity (with TEAC and DPPH methods) were done and phenolic acid composition was determined by HPLC analysis. The data were evaluated statistically.At total phenolic content analysis, Karalahna wine has reached highest value at both three stages of 2,713 mg/mL at average. Fermentation was the stage that highest phenol content has been reached. The prevailing wine for antioxidant capacity was again Karalahna in both DPPH and TEAC analysis and the prevailing stage was fermentation. HPLC analysis has shown that Karalahna had the richest content of phenolic acids.In conclusion from the wines that were produced in Bozcaada, Karalahna grapes had the richest phenolic content of all. From the stages of wine making end of fermentation was the one that had the highest antioxidant capacity and phenolic content.Keywords: Bozcaada, red wine, antioxidant capacity, phenolic content, winemaking stages, HPLC.