A COMPARATIVE ACCOUNT OF CONDITIONS FOR SYNTHESIS OF SODIUM CARBOXYMETHYL STARCH FROM CORN AND AMARANTH STARCH

Conditions for the preparation of carboxymethyl derivatives of corn an d amaranth starch were compared. The two starches differed considerabl y with respect to the optimum conditions such as temperature, pH, time , concentration of sodium monochloroacetate, and starch:liquor ratio. In both cases, isopropyl alcohol was the solvent of choice. Multistage carboxylation was also carried out. Amaranth starch differs from corn starch in two respects. It is waxy in nature and also has a small gra nule size of 1-2 mu m. However, comparison with rice starch, having a granule size of 1-2 mu m and potato starch, having a similar amylose c ontent as corn starch showed no correlation between any of these param eters.