Characterization, Functional Properties, and Resistant Starch of Freshwater Macrophytes.

Several aquatic macrophytes such as , , , , , and possessed carbohydrate mainly in their storage and reproductive parts. Starch morphology, total starch, and amylose content of these six freshwater plant species were determined. Their functional properties, i.e., starch crystallinity, thermal properties, and rheological behaviour were assessed. Large starch granules were in rhizome (>15 m), medium-sized was seed (8-18 m), while the rest of the starches were small starch granules (<8 m). Shapes of the starch granules varied from oval and irregular with centric hilum to elongated granules with the eccentric hilum. corm starch had significantly higher total starch content (90.87%), followed by corms of (82.35%) and (71.71%). seed starch had significantly higher amylose content (71.45%), followed by (36.47%). In comparison, the waxy starch was in rhizome (7.63%), seed (8.83%), corm (10.61%), and rhizome (13.51%). Higher resistant starch was observed mostly in rhizomes of (39.34%)> (37.19%) and corm parts of (37.41%)> (35.09%) compared to seed and pollen starches. The XRD profiles of macrophytes starches displayed in all the corms and seed had A-type crystallinity. The seed had C-type, whereas the rest of the starches exhibited C-type crystallinity. Waxy starches of corm had higher relative crystallinity (36.91%) and viscosity (46.2 mPa s) than regular starches. Based on thermal properties, high-amylose of seed and pollen resulted in higher gelatinization enthalpy (19.93 and 18.66 J g, respectively). Starch properties showed equally good potential as commercial starches in starch-based food production based on their starch properties and functionality.