Pigment profile of red wines cv. Tannat made with alternative winemaking techniques

The pigment profile of Tannat red wines made with different winemaking techniques was evaluated over one year. The wines were made with one traditional and three alternative winemaking techniques: traditional maceration (TM), cold pre-fermentative maceration (CPM), delayed extraction of anthocyanins (DEA), and extended maceration (EM). Two vinifications were carried out for each technique, using 70 kg of grapes per technique. The wines were analyzed at devatting and 3, 6 and 12 months later. The pigment composition was analyzed by HPLC-DAD. The anthocyanin content of the control wines (TM) was significantly higher at all times. At devatting, the contents of 10 grape anthocyanins and some of their derived pigments showed statistical differences between the control wines and the other wines. The levels of vitisin A in the control wines showed no statistical differences with the levels in the CPM wines, but they were significantly higher than in the other wines. One year later, the TM wines showed significantly higher content only of delphinidin and petunidin 3-glucosides, delphinidin acetyl-glucoside and malvidin coumaryl-glucoside pyruvate. The TM and the CPM wines showed higher content in vitisin A and other anthocyanin-derived pigments. The concentrations of some derived pigments, like vitisin A, increased with time in all the wines, while the concentration of the grape anthocyanins decreased highly significantly. Discriminant analysis of the data showed a significant separation of the wines obtained at different ageing times, in spite of the important differences that resulted from the different winemaking techniques.