THE STUDY OF RHEOLOGICAL AND SORPTION PROPERTIES OF PECTINESTERASE SOLUTIONS FROM THE LEAVES OF SORBARIA SORBIFOLIA

Currently, searching for new sources of raw materials of biologically active substances of plant origin is very important. Widespread distribution, relatively easy isolation and high physiological activity have made the practical use of pectins attractive. That is why nowadays an intensive study of the relationship between the structure and physico-chemical properties of pectin polysaccharides is being carried out, and the studies of the sorption and complexing pectin properties are also being expanded.The aim of the work was to study rheological properties of aqueous solutions of pectin substances obtained from the leaves of Sorbaria sorbifolia (L.).Materials and methods. Secretion of polysaccharides from the leaves of Sorbaria sorbifolia was carried out fraction by fraction on the basis of N. K. Kochetkov and M. Sinner’s method. We evaluated the adsorption capacity basing on the experimental data. From the literature data it follows that the adsorption process can be described by Freundlich’s or Langmuir’s equation. The applicability of the particular equation depends on the nature of the adsorbent and the concentration of the adsorbate.Results and discussion. In the course of the work polysaccharides were isolated from the leaves of Sorbaria sorbifolia and some of their physico-chemical properties were studied. The average molar mass of pectic substances was determined as 32923. The influence of the pH medium on the viscosity of solutions of pectin substances was studied and it was found out that a distinct minimum viscosity is observed at pH 5.2. In such an environment the molecules of pectic substances are electrically neutral and the polyelectrolyte is in the isoelectric state. The obtained data show that the maximal binding of Pb2 + ions by pectin leaves of Sorbaria sorbifolia within 50 minutes is 60.0%.Conclusion. The determination of the average molar mass and the isoelectric point makes it possible to specify the possibility of the most effective use of plant raw materials. Physical and technological properties of pectic substances depend on their molar mass. By the value of the obtained isotherms we should arrive at the conclusion that the dependence of the adsorption amount on the equilibrium concentration of lead ions is more subject to Langmuir’s equation.

leaves of Sorbaria sorbifolia, polysaccharides, average molar mass, isoelectric point, sorption