Structural and physicochemical characters of starch isolated from tubers of an aquatic plant Aponogeton natans using modern analytical tools

Aponogeton natans, an aquatic floating plant belonging to the family Aponogetonaceae, is endemic to India. Its tubers have been traditionally consumed by various tribal communities in India, either raw or after processing. The starch was extracted from the tubers of Aponogeton natans, and its physicochemical properties were analyzed using UV–Vis spectrophotometry, scanning electron microscopy (SEM), zeta potential analysis, X-ray diffraction (XRD), and differential scanning calorimetry (DSC). The tubers of Aponogeton natans yielded 77.4% starch, of which 87.6% was amylose. SEM analysis revealed that the starch granules were spherical with a smooth surface. The zeta potential value indicated good colloidal stability. The XRD and DSC analyses confirmed the presence of B-type starch polymorphs. Aponogeton natans could serve as an important dietary source of starch due to its high amylose content, which contributes to increased retrogradation and resistant starch formation. The study suggests potential applications of this starch in the food processing and pharmaceutical industries, owing to its unique properties.