Extraction of polyphenolic compounds from grape seeds with near critical carbon dioxide.

A new analytical method using near critical carbon dioxide to extract polyphenolic compounds from white grape seeds has been developed. Carbon dioxide density, organic modifier, percentage of modifier, and extraction temperature were optimized utilizing an experimental design. Gallic acid, catechin, and epicatechin were the main phenolic compounds detected in the HPLC chromatogram of each extract. Recovery and reproducibility of catechin from grape seed was calculated. Under optimized conditions recovery was estimated to be 79% with a RSD equal to 7.3%. Results from the supercritical fluid method were compared with results obtained via liquid-solid extraction using methanol-water.