Effects of prefermentative cold soak on polyphenols and volatiles of Aglianico, Primitivo and Nero di Troia red wines

Effectiveness of prefermentative cold soak (PCS) on polyphenols and volatiles extraction during winemaking of three red grape cultivars grown in southern Italy (Aglianico, Primitivo and Nero di Troia) was investigated. Four 200-L stainless steel horizontal rotary wine fermenters were used. The main result was that PCS improved the extraction of polyphenols and increased the antioxidant activity of wines. Extraction of proanthocyanidins was enhanced (+25%, +14% and +7% for Aglianico, Primitivo and Nero di Troia, respectively) and, consequently, the ratio flavans reactive with vanillin/proanthocyanidin was reduced, thus potentially favoring the chromatic and tannic stabilization of wines. As regards volatiles, PCS increased ester compounds at levels above their odor thresholds, potentially conferring fruity odor to wines. In conclusion, PCS could be favorably introduced in winemaking to enhance the enological potential of Aglianico, Primitivo and Nero di Troia wines.