Physicochemical properties, morphological and X-ray pattern of chemically modified white sorghum starch. (Bicolor-Moench)

Abstract

Starch isolated from white sorghum was subjected to chemical modifications like oxidation, acetylation and acid thinning. Proximate composition of these, such as crude protein, crude fat, moisture content and ash content were studied. Wide angle X-ray diffractograms showed typical 'A' pattern characteristic of cereal starches, but significant differences were observed between the X-ray pattern of native and modified starches. Scanning electron microscopy revealed round and polygonal shapes for the starch granules with heterogeneous sizes and chemical modifications altered the starch granules morphology. Swelling power and solubility increased with increasing in temperature. Swelling power increased upon acetylation but decreased during acid thinning and oxidation. Solubility increased in these three modifications compared to the native starch. © 2011 Association of Food Scientists & Technologists (India).