The present invention aims at enhancing purity of the proanthocyanidin extracts by acting yeast to the proanthocyanidin extracts for fermenting them to thereby assimilate the impurities such as saccharides with yeast to reduce them.
To provide a method for the manufacture of polyphenols that enables industrial manufacture of polyphenols containing water-soluble proanthocyanidins from grape seeds.
The present invention provides a novel process for extraction, purification and concentration of polyphenol substances from whole grapes, grape seeds and grape pomace without the need for membrane filtration. Aspects of several embodiments of the novel processes include hot water extraction, a dual pH treatment of the hot water extracts, and the uses of a copolymer of trimethylolpropane trimethacrylate as an adsorbent resin to maximize the concentration and purification of the beneficial polyphenolic substances.
The present invention relates to a process for purifying dimeric to pentameric proanthocyanidin oligomers which comprises extracting the proanthocyanidin oligomers from raw materials containing the proanthocyanidin oligomers or crude purification products therefrom by solid-liquid extraction using methyl acetate as a liquid phase; a process for purifying dimeric to pentameric proanthocyanidin oligomers which comprises pretreating with an enzyme for hydrolysis raw materials containing the proanthocyanidin oligomers, crude purification products therefrom, or a solution containing one of these; and a process for purifying dimeric to pentameric proanthocyanidin oligomers with a uniform polymerization degree which comprises separating and purifying the proanthocyanidin oligomers by polymerization degree from raw materials containing the proanthocyanidin oligomers or crude purification products there from by normal phase silica gel liquid chromatography using as a mobile phase a single solvent or a mixed solvent of two or more solvents selected from the group consisting of an ester solvent, a ketone solvent, a hydrocarbon solvent, an ether solvent and an alcohol solvent.
This invention includes both a one-column process and a two-column process for the preparation of compositions enriched for anthocyanins from a crude plant extract. Both processes include a novel column purification step using a brominated polystyrene resin. This invention also includes extracts enriched for anthocyanins.
