Studies on preparation and functional properties of carboxymethyl starch from sorghum

Attempts were made to explore the potential of hybrid sorghum (Variety CSH-9) to prepare starch by wet milling process. Starch yield from sorghum found to be 72.5 percent. The starch so prepared was further utilized for the production of carboxymethyl starch (CMS) derivative. The reaction conditions during chemical modification of sorghum starch such as reaction time and monochloroacetic (MCA) acid concentration were optimized. Reaction time of 90 min. and 15 ml of 40 percent MCA acid (w/v) resulted in the maximum DS of CMS. The functional properties of CMS like swelling power, solubility and rheological properties were studied. The solubility and swelling power of sorghum CMS were maximum at 70°C. Apparent viscosity of sorghum CMS yielded 1172 Cps at 90°C using shear rate 4.51 per second. The viscosity of CMS was found to be less as compared to native starch.