Characterization of grape seed aqueous extract and possible applications in biological systems

Abstract

Grapes (Vitis vinifera L.) belong to world's largest fruit crops. Since about 80% of the total amount is used in wine-making, the rest of 20% (about 10 million tons) of grape pomace arises within a few weeks from the harvest campaign. The seeds constitute a considerable ratio of the pomace, amounting to 38-52% on a dry matter basis. The results of certain studies have indicated that the polyphenols present in grape seeds in significant concentrations could be classified into two groups: flavonoids and non-flavonoids. The present study employed high-performance liquid chromatography (HPLC) to analyze the phenolic compounds in the seed extract. Spectrophotometric methods were employed for the determination of total phenolic content, total tannins, flavonoids, flavanols and antocyanins. The aqueous polyphenols extract obtained from grape seeds was analyzed in germination tests, to evaluate the response of three different plants (oat, rape and maize) in terms of growth and development. Biometrie measurements and quantitative determination of green biomass showed that grape seed extract amendments stimulated root elongation for oat and maize, as well as green biomass accumulation.