Structural and thermodynamic properties of starches extracted from GBSS and GWD suppressed potato lines.

A combined DSC-SAXS approach was employed to study the effects of amylose and phosphate esters on the assembly structures of amylopectin in B-type polymorphic potato tuber starches. Amylose and phosphate levels in the starches were specifically engineered by antisense suppression of the granule bound starch synthase (GBSS) and the glucan water dikinase (GWD), respectively. Joint analysis of the SAXS and DSC data for the engineered starches revealed that the sizes of amylopectin clusters, thickness of crystalline lamellae and the polymorphous structure type remained unchanged.

Annealing of normal and mutant wheat starches. LM, SEM, DSC, and SAXS studies.

Structure and thermodynamic properties of native and annealed wheat starches with different amylose content (from 1.5% to 39.5%) have been studied by high-sensitivity differential scanning microcalorimetry (HSDSC), small-angle X-ray diffraction (SAXS), light (LM), and scanning electron microscopy (SEM).

Structural parameters of amylopectin clusters and semi-crystalline growth rings in wheat starches with different amylose content.

Small-angle X-ray scattering (SAXS) and scanning electron microscopy (SEM) were used to investigate the internal structure of wheat starch granules with different amylose content. Different approaches were used for treatment (interpretation) of SAXS data to assess the values of structural parameters of amylopectin clusters and the size of crystalline and amorphous lamella in different wheat starches. The average values of the semi-crystalline growth rings thickness in starches have been determined and the relationship between structural characteristics and thermodynamic melting parameters is discussed.