Structural studies on methylated starch granules

Granules of potato starch and amylopectin potato starch were methylated in aqueous alkaline suspension. Here, an overview is given of all structural a spects that have been studied with respect to the determination of the loca tion of the substituents. Methods. which are generally applicable, were dev eloped for the separation of different areas of derivatised starch granules . followed by determination of the substitution level. For methylated starc h granules it was found that methyl groups are predominantly present in bra nched regions and amorphous domains, and that amylose is higher substituted than amylopectin. No differences were found between substitution levels of granules of various sizes, nor radially across the granules.