Effect of skin contact on the aroma composition of the musts of Vitis vinifera L. cv. Muscat of Bornova and Narince grown in Turkey

The effect of skin contact treatment (12 h, 15 °C) on free and glycosidically-bound aroma compounds of musts of Muscat of Bornova and Narince used in winemaking was studied. Free and bound aroma compounds were extracted with dichloromethane and Amberlite XAD-2 resin, respectively, and then analysed by gas chromatography–flame ionisation detection (GC–FID) and gas chromatography–mass spectrometry (GC–MS). In Muscat of Bornova must, 32 free and 23 bound compounds were identified. Terpenes were the dominant compounds in free and bound fractions. Linalool and trans-linalool oxide pyran in the free fraction, and nerol, geranic acid and geraniol in the bound fraction were the most abundant terpene compounds in this must. In Narince must, 19 free and 12 bound compounds were identified, and C6 compounds were the most abundant. Skin contact treatment significantly increased the total free aroma compounds, particularly terpenes, hexanol, benzyl alcohol and 2-phenylethanol.