A COMPARISON OF THE MOLECULAR-PROPERTIES OF SORGHUM STARCHES OF DIFFERENT ORIGINS

The molecular properties of 3 sorghum starches and their components were compared by methods involving I-staining, enzymatic degradation and gel chromatography. The starches from the red and chalky varieties were very similar in properties and in amylose to amylopectin ratio, but differed in their MW distribution profiles. The waxy sorghum starch was fractionated by the thymol-butanol method to yield a small quantity of amylose. The 3 starch samples were all resistant to dissolution in boiling water, but when subjected to physical damage, the granules became partly soluble in cold water and almost totally soluble in boiling water.