Starch

Pearl millet starches show significant variation in their physicochemical, thermal, morphological and rheological properties. Significant (p <0.05) variation in amylose content was observed and it varied from low amylose to high amylose starch. Pearl millet starch granules showed small to large, round, spherical and polygonal granules with some pores and indentation and size of starch granules varying from 3 µm to 23 μm. Pasting properties of starches varies with concentration of starch and the method used for analysis. For analysis of thermal properties, differential scanning calorimetry was used and gelatinization transition temperatures To (onset), Tp (peak), Tc (endset), and the enthalpy of gelatinization (ΔHgel) were analyzed. The crystalline patterns of pearl millet starches were determined by their X-ray diffractions and A-type crystalline patterns were observed, which is a characteristic of cereal starches. Steady and dynamic shear properties were studied using a rheometer. Storage modulus (G′) values for starch pastes were observed more than loss modulus (G′′) and tan δ (G′′/G′) value of starches was less than 1, indicating that their behavior is elastic rather than viscous. It is suggested that more research is needed to diversify the variations in the properties and to improve the utilization of this starch.