Résumé
Optimization of polyphenol extraction from grape skin, seed, and pulp was performed on Vitis vinifera L. cv. Pinot Noir, by response surface methodology using a Doehlert design. An acidified mixture of acetone/water/methanol was the best solvent for simultaneous extraction of major polyphenol groups from all berry parts, while optimum extraction times and solid-to-liquid ratios varied according to the part. The determined composition from the model agreed with independent experimental results. Analysis of the three Champagne grape varieties showed that proanthocyaniclins were the major phenolic compounds in each part (60-93%). The total berry proanthocyanidin content was highest in Pinot Meunier (11 g kg(-1)) and lowest in Chardonnay (5 g kg(-1)), but Pinot Meunier pulp contained lower amounts of proanthocyaniclins and phenolic acids (210 and 127 mg kg(-1) berry, respectively) than that of the other two varieties. The berry anthocyanin content was equivalent in both Pinot Noir and Pinot Meunier (632 and 602 mg kg(-1), respectively)