The hydration mechanism in plant polysaccharides: a physicochemical and dielectric study

Polysaccharides play a vitally important part in the lives of plants and animals, both as structural elements and in the maintenance of functional activity. In this work, we investigate the hydration mechanism of various polysaccharides of plant origin and concentrate, more particularly, in the comparison between results obtained with starches of various origin, on the one hand, and cellulose samples, on the other, using equilibrium and dynamic water sorption isotherms, thermally stimulated depolarization currents (TSDC) techniques in the temperature range 77-300 K and dielectric relaxation spectroscopy in the frequency range 10-10⁷ Hz. The dependence of the characteristics of dielectric spectra on the water content and on the nature of the polysaccharide is investigated and their origin is interpreted on the basis of the nature of the polysaccharide and of results obtained in the first part of the work.