Assessment and adaptation of methods of extraction of grape seed polyphenol compounds

Abstract

The extraction of polyphenolic compounds in the plant material is influenced by the chemical and structural characteristics and the particle size of the plant material, as well as the presence of interfering substances. The solubility of the phenolic compounds depends on the solvent used, the degree of polymerization of the compounds, as well as interactions with other plant compounds. The paper presents several methods used for extracting polyphenolic compounds from grape seed: Soxhlet continuous extraction method; extraction with supercritical fluids (liquid CO2); extraction under reduced pressure (3 bar) and high pressure (15 bar) with water and 75% alcohol concentration. Characterization of polyphenolic extracts carried out by HPLC alloweded the recommendation of two methods: with supercritical fluid and Soxhlet method. In the same time it was also observed a higher extraction yelds for the phenolic acids, hydrolysable tannins, flavones of stilbene using alcohol as a solvent.