Influence of winemaking technologies on phenolic composition of Italian red wines

The aim of this study was to assess the influence of different winemaking technologies on the chemical characteristics and, in particular, on the phenolic fraction of Aglianico, Montepulciano, Nero di Troia and Sangiovese wines produced in Apulia, Southern Italy. Four different winemaking technologies were compared: control (traditional, 5 days of maceration at 25 °C with three daily punching-down), prolonged maceration (10 days), addition of ellagic tannins and cryomaceration (24 h at 5 °C using dry ice), without any other oenological treatment. Results showed that the different technologies slightly influenced the phenolic fraction of Aglianico, which is known to be naturally rich of phenols. On the contrary, the prolonged maceration led to an increase of total phenols (TP) in Nero di Troia (2,592 mg/kg vs. 2,115 mg/kg of control) and a decrease in Sangiovese (869 mg/kg vs. 1,013 mg/kg); the addition of tannins led to an increase of TP in Montepulciano (1,358 mg/kg vs. 1,216 mg/kg) and to a decrease in Sangiovese (916 mg/kg vs. 1,013 mg/kg); and cryomaceration led to a decrease of anthocyanins in all cultivars (about 15%). Phenols extraction from grapes was found to be mostly dependent on the grape variety rather than on the applied winemaking technology.