Preparation of Water-Soluble Chitosan and Aloe vera Mucilage and Their Use for Assembly of Polyelectrolyte Complexes

Abstract

In this work, the preparation and characterization of water-soluble polysaccharides from chitosan and Aloe vera was studied. The water-soluble polysaccharides were used to study polyelectrolyte complexes. The reaction time effect for chitosan hydrolysis by endo-chitosanase was studied at 40oC and pH 5.00 to produce water soluble chitosan (WSCh). The physico-chemical characteristics of chitosan hydrolysates, water-soluble A. vera polysaccharides and polyelectrolyte complexes were determined. After 3 h of chitosan processing, a viscosity reduction of 90%, while only 2.3% of reducing sugars were released. A WSCh was recover by ultrafiltration (1 kDa) from chitosan hydrolysate after 12 h and was spray-dried with a yield of 9.7%. Cold-water extraction of A. vera mucilage from pulp gives a crude polysaccharide yield of 0.81 g/kg (wet basis) based on whole leaf weight. The water isolated mucilage is composed of a mixture of protein and mannan rich-polysaccharide. The results show WSCh’s association capacity with A. vera mucilage by electrostatic interaction.