Comparative analysis of the phenolic content of selected Chilean, Canadian and American Merlot red wines.

Flavonoids are a group of naturally occurring antioxidant compounds found in wine that are thought to have therapeutic importance in cardiovascular disease. The flavonoid content of red wines can differ as a function of the variety of wine examined. Since there is a paucity of data on the content of these antioxidants in Merlot wine, we used high performance liquid chromatography to identify and compare catechin, epicatechin, rutin, transresveratrol and quercetin levels in selected Merlot wines from Canada, Chile and the United States. Additionally, antioxidant content was correlated with the price of the wine. Catechin content was the most abundant when compared to the other four phenolic compounds. The concentrations of each compound in the Merlot wines also varied as a function of the country of origin. Catechin and transresveratrol occurred in significantly lower concentrations in Merlots from the United States. The lowest levels of rutin were observed in Canadian Merlots. Quercetin occurred at significantly higher levels in Chilean Merlots. Wine prices were inversely correlated with catechin concentration. Merlot wine represents a source of antioxidants that may have an impact on cardiovascular disease.