Polyphenol extraction from grape skin

Abstract

Many studies reported in the literature show the polyphenol's antioxidant character and their advantages for the human health. It was determined the more adequated conditions for the polyphenol extraction from the skin of grape. The experimental material was previously dryed and milled. The extractions were developed to 55 ºC, solute-solvent ratio of 1:10 (m/v) during 2.5; 4.0; 4.5 and 6 h employing ethanol, mixture ethanol-water 1:1 (v/v), ethyl acetate and water as solvents. Subsequently, extractions to 35, 45, 55 and 65 ºC, solute-solvent ratios of 1:5 and 1:10 (m/v), were developed with the solvent and time obtained as a result of the first experiments. All extractions were by direct contact. The mixture ethanol-water, to temperature between 45 and 55 ºC with 1:10 as solute-solvent ratio reported the bigger values of the antioxidant activity, with an extraction time of 4 h.