Powdered Grewia spp. barks was extracted in water and one part of the extract was precipitated with absolute ethanol. Both the crude water extract and the ethanol precipitate was freeze dried, pulverized into powder and subjected to physicochemical analyses. Amongst others: proximate composition, morphology and metal contents by SEM-EDX, functional group by FTIR, crystallinity by XRD, thermal behavior via DSC and TGA. The molecular mass of the ethanol precipitate was appraised through viscosity measurements and the Huggins plot. Results show that both the crude extract and the ethanol precipitate were rich in polysaccharide type polymers. However, precipitation led to a reduction in the metal contents confirmed by the ash contents and the EDX analysis as well as the absence of sharp peaks on the XRD plots as was the case of crude extracts. Precipitation led to a decrease in the lipid and protein contents initially present in the crude Grewia spp. extracts. XRD and SEM analyses revealed that Grewia spp. extract and the precipitate were both amorphous with a porous microstructure. Results also showed that Grewia spp. biopolymer has functional groups which can serve as active sites for the attachment of colloidal particles

Keywords: Grewia spp. biopolymer; Extraction; Precipitate; Characterization