Content of selected phenolic compounds in wine from rondo grapes grown in denmark and effect of heat and cryomaceration

Studies have shown that red wine contain several polyphenolic compounds, e.g., anthocyanins, catechins, flavonols and stilbenes, which are believed to have beneficial effects on human health. Pre-fermentation treatments are known to increase the content of these compounds in wine, resulting in changes of the sensory characteristics (e.g., flavor, astringency and color). In 2000, Denmark was approved as a wine producing country by the EU and one of the grape varieties cultivated in Denmark to produce red wine is Rondo. In this study we investigated the effect of cryomaceration (liquid nitrogen) and thermovinification (70^oC) vs. a traditional pretreatment (30^oC) on the content of phenolic compounds in the wine produced from Rondo grapes grown on the island of Funen, Denmark. Compared to traditional pretreatment, thermovinification increased the content of anthocyanins, catechin and resveratrol by 62%, 69% and 260%, respectively, but reduced the content of quercetin by 580%, while cryomaceration increased the content of quercetin by 6%, but reduced the content of anthocyanins, catechin and resveratrol by 11%, 9% and 60%, respectively. These results should incite Danish wine producers to implement thermovinification as a pre-fermentation treatment as it intensifies the color of the wine produced (anthocyanins, 313mg/L).