Extraction and characterization of sorghum (Sorghum bicolor L. Moench) starch

Four local Indian varieties of sorghum (CSH-9, CSH-5, Dadar and Parbhani) were subjected for proximate analysis and characterization of extracted starch. Starch from the above varieties was extracted by steeping, wet grinding and sedimentation process. Isolated starch was then characterized for amylose and amylopectin content, gelatinization temperature, viscosity, swelling power, solubility and water absorption capacity (WAC). Maximum amylose content of 19% was found for CSH-9, while Dadar had minimum amylose content of 11%.This gives an indication of utilization of low amylose or waxy starch variety like Dadar for pie-filling and puddings and high amylose variety of CSH-9 for gelling characteristics of cooled and cooked starches. Water absorption capacity (WAC) gave maximum value for Dadar and CSH-9, and minimum for CSH-5.So these varieties can be used in soups and in thickeners for their water holding capacity. Maximum viscosity was reported for Parbhani and CSH-9, and minimum for CSH-5 and Dadar. Gelatinization temperature was varied from 64°C for CSH-9 to a maximum of 68°C for Dadar and Parbhani.