Water-soluble galactomannans from seeds of Mimosaceae spp.

The characterization of four galactomannans from the seeds of Mimosaceae sp p., from natural Southern Brazilian sources having similar chemical structu res with Man:Gal similar to 1, was performed. (CNMR)-C-13 spectra gave clea r information on the chemical structure of these highly branched galactoman nans. Their physico-chemical macromolecular characteristics were determined from SEC experiments, leading to the determination of parameters relating R-G and [eta] with M-w. Applying a model of worm-like chain, a persistence length of L-p similar to 100 Angstrom was determined. The specific viscosit y at zero shear rate was investigated, and demonstrated that a unique curve relates eta(sp) With the overlap parameter C[eta]; in the range of higher values of C[eta], the slope was n = 6.2; the critical concentration c*[eta] = 1.9. Considering the structure and rheological properties, galactomannan from Mimosa flocculosa and Mimosa bimucronata might be potentially applied as thickeners in food and cosmetic products, as well as galactomannan from Mimosa scabrella Benthan, previously analysed. (C) 1998 Published by Elsev ier Science Ltd. All rights reserved.