Effects of removal of surface proteins on physicochemical and structural properties of A- and B-starch isolated from normal and waxy wheat.

The effects of protein removal on the physicochemical and structural properties of normal and waxy wheat and their A- and B-type granule fractions were investigated. No evident changes were observed in the morphological, birefringence pattern and X-ray diffraction pattern after treatment, but there was evidence showing that the relative crystallinity, swelling power and percentage syneresis of all samples were significant increased. Protein removal treatment increased the peak, setback, final viscosity, breakdown viscosity of normal and waxy native wheat starch, and their A- and B-type starch granule fractions, whereas it decreased the pasting temperature, peak time and trough viscosity.

Recrystallization characteristics of high hydrostatic pressure gelatinized normal and waxy corn starch.

High hydrostatic pressure (HHP) can lead to starch gelatinization at room temperature, while the retrogradation mechanism of HHP gelatinized starch is not well known. HHP gelatinized normal and waxy corn starches were stored at room temperature for 192 h in order to investigate the retrogradation characteristics. The scanning electron microscopy (SEM), polarised light microscopy and differential scanning calorimetric (DSC) analysis showed that the pressurization of normal and waxy corn starch suspensions with concentration of 30% (w/v) at 600 MPa for 15 min resulted in a complete gelatinization.

Physicochemical characteristics of high pressure gelatinized mung bean starch during recrystallization.

The changes in physicochemical and structural properties of Ultra high pressure (UHP) gelatinized mung bean starch were investigated during 0 to 196h retrogradation process by using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). XRD analysis showed that the UHP-gelatinizated granules regenerated its original C-type crystallinity structures after retrogradation. The swelling power and solubility of native starch were increased with the increase in the assay temperatures from 50 to 90°C, while the changing trend of the retrogradated granules was more gradual over entire assay temperatures.

Physicochemical properties of A- and B-starch granules isolated from hard red and soft red winter wheat.

Large A- and small B-starch granules separated from hard red and soft red winter wheat grains were investigated for their morphological, structural, and physicochemical properties. A-granules displayed a disk or lenticular shape, and B-granules showed a spherical or polygonal shape according to SEM. XRD analysis showed that both A- and B-granules had A-type crystallinity.

Effect of nitrogen and sulfur fertilization on accumulation characteristics and physicochemical properties of A- and B-wheat starch.

The effects of nitrogen (N) fertilization at the rates of 0 and 230 kg hm(-2) combined with selected sulfur (S) fertilization rates of 0, 46, 56, 77, and 115 kg hm(-2) on A- and B-wheat starch granule accumulation, composition, and thermal and pasting properties were investigated. Scanning electron micrographs revealed that A- and B-starch granules accumulation during grain filling can be influenced significantly by N and S fertilization, and B-granules tend to be more sensitive to S fertilization than A-starch granules. The doses of nitrogen and sulfur fertilization on starch properties were not positively correlated; higher concentration of fertilizers failed to cause a higher effects.