| Cross-linked carboxymethyl rice starches (CL-CMRSs) were prepared from reactions between native rice starch and varied concentrations (0.1 to 15%w/w) of epichlorohydrin (ECH) in a simultaneous carboxymethylation-crosslinking reaction setup using methanol as solvents. The degree of carboxymethyl substitution was between 0.24 to 0.28, while amylose content decreased drastically from native starch. SEM images showed minor change on the granule surface, while XRD profiles indicated slight loss of crystallinity. In contrast, the water uptake (WU) and free swelling capacity (FSC) of CL-CMRSs increased significantly, compared to native starch, as a result of the modification. CMRSs cross-linked with 2% (M-2) and 3% (M-3) ECH yielded FSC values of 8.6 and 9.6 g/g,... |
