Antioxidant Content and Function in Selected Merlot Wines from Chile and Canada
Grant N. Pierce, Randolph S. Faustino, Salisha Sobrattee and J. Alejandro Austria.
The National Centre for Agri-food Research in Medicine, and the Division of Stroke & Vascular Disease, St. Boniface General Hospital Research Centre and the Dept of Physiology, University of Manitoba, Winnipeg, Canada
Despite a relative abundance of risk factors in the French populace, the low incidence of heart disease has lead to the phenomenon being labeled as the "French Paradox". It has been proposed that the high antioxidant content within red wine may provide significant protection against heart disease. Characterizing the content of antioxidants in wine and understanding how they work has become an important issue relevant to industry as well as medical research. Merlot wines have an increasing popularity in North America. We have examined by HPLC the content of five important antioxidants found in selected Merlot wines from Chile and Canada. The contents of catechin, epicatechin, rutin, transresveratrol were similar between the wines from the two countries. Quercetin content in the Chilean Merlots was significantly higher than the Canadian wines. Interestingly, the price of the wine did not correlate with the content of any of the five antioxidants. Aliquots of the wines and the individual antioxidant species protected low density lipoprotein (LDL) from oxidation from free radicals generated by AAPH. The Canadian and Chilean Merlots did not differ significantly with regard to their antioxidative capacity. None of the five antioxidants could protect LDL from oxidation by AMVN. Conversely, the wines contained an unexpected ability to protect LDL from oxidation by AMVN. These data suggest that Merlot wines from Chile and Canada may contain unrecognized antioxidant species that protect LDL from oxidation in both a lipid and aqueous environment.