The effect of fermentation conditions on polyphenolic compounds and antioxidant activity of öküzgözü wines

In this study, the effect of different fermentation and winemaking techniques on the phenolic contents and antioxidant activity of okuzgözü wines has been investigated.Öküzgözü red wines were made by different fermentation techniques such as spontan (without yeast and enzyme addition), classic (with yeast addition), fermentation with enzyme preparation (with yeast and enzyme addition) and heated maceration (with yeast, pre-heating at 65oC for 8 h) with skin and skin+seed contact for five days at 25oC. Phenolic compounds and anthocyanins were determined by spectrophotometric and HPLC methods. Antioxidant activity was evaluated by DPPH free scavenging activity test.By the end of fermentation, while wines made with seed and skin must contact had more phenolic compounds (total phenolic and total flavanol) than those of made by only skin must contact, anthocyanins were higher in skin must contacted wines. Highest total phenolic content and antioxidant activity were found in wines made by pre-heating at 65oC for 8 h before fermentation. All phenolic compounds were affected by wine making techniques after seed/seed+skin must fermentation.