OXIDATION OF MOGHAT MUCILAGE WITH SODIUM-CHLORITE

Egyptian moghat mucilage was subjected to oxidation using sodium chlor ite under different sodium chlorite concentration. pH, reaction time a nd temperature. The products were analyzed for the acidic and reducing properties expressed as carboxyl and carbonyl contents, respectively. The rheological properties of the oxidized samples were also measured by making use of cooked pastes at a concentration of 5%. The results obtained indicate that the acidic and/or reducing properties increase as the sodium chlorite concentration. the time and/or the oxidation te mperature increase. The carboxyl and carbonyl contents exhibit the hig hest value at pH 4. Pastes of the oxidized moghat mucilage are charact erized by pseudoplastic or thixotropic behaviour depending on the degr ee of oxidation. Oxidation changes the rheological characteristics of the mucilage either from a high degree of thixotropy to a relatively l ower degree, or from thixotropic to pseudoplastic. The lowest apparent viscosity was observed with the sample oxidized at pH 4. The apparent viscosity decreases with increasing sodium chlorite concentration and /or time of oxidation. Reaction mechanisms involved in the oxidation o f moghat mucilage with sodium chlorite are also reported. (C) 1997 Pub lished by Elsevier Science Limited.