Characterization of starch by dual role of ~(60)Co-γ ray and microwave irradiation

Modified starch by double irradiation of 60Co-γ ray and microwave was prepared,and its pasting temperature and solubility were tested.The results indicated that when compared with corn starch and H2O2 oxidized starch,this radiation modified starch had higher pasting temperature and solubility,but lower viscosity.The content of amylose and amylopectin of the radiation modified starch were determined using butanol sedimentation process,and it was found that the content of amylose was as high as 58.9% as compared with the corn starch,the degradation rate of the amylopectin was 54.8%.This meant that the molecular chain of the starch was damaged by γ ray and microwave irradiadtion,and a considerable part of the amylopectin was broken down so that the amylose content increased and the modified starch became easier to dissolve in the hot water and form a good solution.