Orosensory profiles and chemical composition of black currant (Ribes nigrum ) juice and fractions of press residue.

Fractionation of black currant ( Ribes nigrum ) by juice pressing, four ethanol extractions, ethanol evaporation, and supercritical fluid extraction was studied. Phenolic compounds, sugars, and acids of the fractions were analyzed by high-performance liquid chromatography and gas chromatography. Sensory properties of the fractions were studied using generic descriptive analysis. Most of the sugars and acids were located in the juice, whereas the majority of the phenolic compounds were in the press residue. Ethanol extracted nearly all of the phenolic compounds from the press residue, leaving only fibers and seeds. The juice was dominant in most of the sensory attributes, whereas the extracts were perceived as most astringent. Three flavonol glycosides [kaempferol-3-O-(6''-malonyl)glucoside, myricetin-3-O-galactoside, and an unknown kaempferol glycoside] were discovered to be the compounds especially contributing to astringency. Ethanol extraction appeared to be an efficient and simple way to isolate phenolic compounds from black currant juice press residue.