Additional Information on Starch Complexation

Novamont s Mater-Bi starch-based technology implies processing conditions able to destroy the crystallinity of amylose and amylopectin, in the presence of macromolecules, such as specific polyesters, which are able to form a complex with amylose. They can be of natural or synthetic origin. The specification of the starch, that is, the ratio between amylose and amylopectin, the nature of the additives, the processing conditions and the nature of the complexing agents allow engineering of various supramolecular structures with very different properties. 

A droplet-like structure, where a core of an almost amorphous amylopectin molecule is surrounded by complexed amylose molecules, has been confirmed by transmission electron microscopy (TEM) analysis of film slices [90], The droplet size is comparable with that of the microdispersion obtained by boiling. 

This peak is attributed to starch ring vibrations [92, 120], and does not correspond to crystalline or gelatinized amylose but to a complexed one, which results when amylose assumes V-type structures conformations after destructurization. Comparable starch-based materials with an amylose content close to zero, even in presence of complexing agents, do not show any peak at 947 cm.  

V-type structure formation can be also detected, by X-ray diffraction analysis and CP-MAS solid state NMR [121-124]. 

As far as X-ray diffraction analysis is concerned (WAXD), characteristic peaks of different V-type structures can be detected on destructurized starch in presence of complexing agents 

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