Abstract:

The change of physicochemical properties of wheat starches was studied after microwave irradiation.Wheat starches were treated at a moisture content of 30% by microwave irradiation.The results showed that the surface was porous and a concavity could be clearly observed at the center of starches.Microwave treatment increased the X-ray intensities of the major d-spacings of starches.The swelling power,solubility, syneresis and the enthalpy of gelatinization decreased on this treatment.Microwave treatment increased the gelatinization transition temperatures and the gelatinization temperature range of starches.The rise in pasting temperature and the drop in viscosity of wheat starches were observed after microwave irradiation.However, the viscosity patterns remained unchanged.Associations involving starch chains (amylose-amylose and amylose-amylopectin) with the amorphous and crystalline regions of the granule resulted in the formation of new crystallites of different stabilities and led to more ordered crystalline array.