Interactions of Starch and Other Polysaccharides with Condensed Tannins in Hot Water Extracts of Ponderosa Pine Bark

Publisher Website
Google Scholar
Abstract
Hot water extraction of Ponderosa pine bark yields condensed tannins (polymeric procyanidins, PPC's) and starch. Precipitation of the PPC's as the lead complex coprecipitates the starch, although the latter does not itself form an insoluble lead complex. Ethylene diamine tetraacetic acid (EDTA) treatment of the lead complex removes lead and yields PPC and starch which coprecipitate with ethanol from water as a starch-PPC complex, although the PPC itself is fully ethanol soluble. Chromatography of the starch-PPC complex with water on several polysaccharide media leads to elution of the starch and sorption of the PPC. Similar interactions of PPC and polysaccharides may be responsible for viscosity problems in uses of condensed tannins as tans and as adhesives. Such interactions probably occur in many plant materials.