Structural Studies on Methylated Starch Granules
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English Slovak |
| ISSN: | ISSN 0038-9056 |
| Online Access: | http://www.viks.sk/chk/star_2_3_00_40_43.doc |
| Abstract: | Summaries. Granules of potato starch and amyiopectin potato starch were methylated in aqueous alkaline suspension. Here, an overview is given of all structural aspects that have been studied with respect to the determination of the location of the substituents. Methods, which are generally applicable, were developed for the separation of different areas of de-rivatised starch granules, followed by determination of the substitution level. For methylated starch granules it was found that methyl groups are predominantly present in branched regions and amorphous domains, and that amylose is higher substituted than amyiopectin. No differences were found between substitution levels of granules of various sizes, nor radially across the granules. Conclusions. The results of the structural analysis on methylated starch granules corroborate the current view on the structure of starch. Crystalline domains are less accessible for chemical substitution than amorphous parts. These crystalline lamellae are built up from amylopectin side chains, of which the glucose residues close to the non-reducing ends and the branching points are substituted predominantly. Amylose is present in amorphous domains of the granule and is therefore highly substituted. The development of methods that are generally applicable in the structure elucidation of starch derivatives has been successful. The distribution of substituents in methylated starch granules has been described considering different regions, domains and molecules and granule sizes. These methods can now be used in the structural analysis of other kinds of starch derivatives. That would open the way to an unter-standing of the relationships between molecular structure and functional properties, like the viscosity or stability of a starch gel. |
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| ISSN: | ISSN 0038-9056 |
