The Influence of Skin Maceration Time on the Phenolic Composition and Antioxidant Activity of Red Wine Teran (Vitis vinifera L.).

The effect of four different maceration times (5, 10, 15 and 20 days) on anthocyanins, phenolic acids (hydroxybenzoic, gallic, protocatechuic, vanillic, syringic, caffeic and p-coumaric acids), flavan-3-ol composition, vanillin index and antioxidant activity of Teran red wine (Vitis vinifera L.) has been investigated. Phenolics were determined by HPLC with UV-diode array detection. Vanillin index was determined by UV-VIS spectrophotometry. The total antioxidant capacity of wine was measured with three different methods: 2,2-diphenyl- l-picrylhydrazyl (DPPH) radical and 2,2'-azinobis(3-ethylbenzothialozine-6-sulphonic acid) radical cation (ABTS⁺) scavenging methods and ferric reducing antioxidant power (FRAP). Sensory evaluation of wine samples was performed. The obtained results show positive correlation between phenolic acids, flavan-3-ols [(+)-catechin and (-)-epicatechin] and vanillin index and the duration of maceration. Anthocyanin content increased to the maximum within 10 days of skin maceration. The major anthocyanins in Teran wine were malvidin-3-O-glucoside, malvidin-3-glucoside acetate and petunidin-3-O-glucoside. Antioxidant activity of Teran wines significantly increased with prolonged skin contact as well as total phenolic content (p<0.001). Wine produced with maceration time of 10 days had the best sensory properties. [ABSTRACT FROM AUTHOR]