Influence of different vinification techniques on stilbenes and total polyphenolic content in Teran wines

The aim of this work was to study the influence of different vinification techniques on stilbenes and total polyphenolic content in red wines made from cv. Teran (Vitis vinifera L.). Four different vinification techniques were carried out: control (7 days maceration), prolonged maceration (10 and 21 days), and thermovinification. Four stilbenes were determined by high-performance liquid chromatography (HPLC), and total polyphenols were determined by spectrophotometric methods. The results showed the treatment of extended maceration (21 days) had a significant effect on the increase of total (35.74 mg/L) and individual stilbenes (trans-piceid, cis-piceid, trans-piceatannol, trans-resveratrol), as well as total polyphenols (2702.88 mg GAE/L). Treatment of thermovinification resulted in significant increase of the total polyphenolic content by nearly 20% in relation to control.