Antioxidant capacity and phenolic composition of red wines from various grape varieties: Specificity of Pinot Noir.

Wines produced from various grape varieties present different properties affecting taste and color. The hypothesis was that grape genotype could have a deep impact on wine antioxidant properties and phenolic composition. But in this study on 38 different wines of 4 main grape varieties, large variability in the levels of individual phenolic compounds as well as in antioxidant capacity was observed in each grape variety. Comparisons of the wine varieties based on their individual phenolic profile (flavonols, anthocyanidins, flavan-3-ols, phenolic acids, resveratrol…) and antioxidant capacities (ORAC, DPPH, hemolysis, ESR, total phenolics) showed limited differences. An exception was the group of wines made from the grape variety Pinot Noir, in which the range of phenolic compounds was different from the other wines: anthocyanidins (87 mg L-1, 119 to 206 mg L-1 in other grape varieties) and flavonols (17 mg L-1, 20 to 57 mg L-1in others except Primitivo) showed lower levels while flavanols (327 mg L-1, 152 to 244 mg L-1 in others) and phenolic acids (161 mg L-1, 103 to 152 mg L-1 in others) showed levels higher than in the other wines. This different profile was associated with a lower antioxidant capacity (i.e. mean ORAC value: 20988 for Pinot Noir, 27820 to 33651 for others).