Concentrates of polyphenols from grape raw materials and their functional properties

Abstract

The work presents the possibility of obtaining polyphenol concentrates from raw materials (pomace, seeds, cane, vines, leaves) of Crimean grapes of white varieties Aligote, Rhine Riesling, Rkatsiteli and grapes of red varieties Muscat Hamburg, Cabernet-Sauvignon, by vacuum concentration of alcoholic extracts of grape raw materials. An experimental assessment on the qualitative and quantitative structure of polyphenols, the basic functional ingredients of biological activity of grapes has been given. It has been established that by concentration of phenolic substances, the concentrates are distributed in the following sequence: seeds of grapes of white and red varieties, stalks of grapes of white and red varieties, pomace of grapes of red varieties, leaves of grapes, vine of grapes, pomace of grapes of white varieties. In grape concentrates, anthocyanins, flavones, flavan-3-ols, oligomeric and polymeric procyanidins, oxycinnamic and oxybenzoic acids and stilbenoids have been identified. The maximum quantitative evaluation of stilbenoid concentration obtained in grape concentrates was up to 5.0 g/L, which is by order of magnitude greater than in red wines. The antioxidant activity indicator (AOA), estimated in vitro in grape seed concentrate, ranged from 180.0 to 250.0 g/l, which is by order of magnitude greater than in red grape wines.