Abstract:
In this paper,high linear(65% linear),ordinary(28% linear),95% branched and waxy(99% branched)corn starch was studied,and the temperature was attenuated by pullulanase. The above two components of the supernatant and the precipitate were characterized by SEM,laser particle size analyzer,FTIR,DSC,XRD,thermogravimetric analyzer,and the morphology of the recrystallization supernatant and precipitate were analyzed by different branch ratio,crystal structure,thermal properties and other aspects. The results showed that the yield of recrystallization supernatant increased with the increasing of branching ratio,while the precipitation yield showed a downward trend. Scanning electron microscopy and laser particle size analyzer showed that the supernatant particle size increased and the precipitation particle size decreased with the increasing of branching ratio. FTIR,DSC and XRD showed that as the proportion of branching increased,the proportion of crystallization and crystallization of the supernatant(the crystallization zone and the amorphous zone)increased,while the precipitated crystallization zone and crystallization zone proportion of the total(crystalline and amorphous)was reduced. Thermogravimetric analysis showed that the thermal stability of the supernatant increased with the increasing of the proportion of branches,while the thermal stability of the precipitate decreased with the increasing of the proportion of branches.