Thermodynamics properties and absorbability of four modified corn starches
Corn starch was used to prepare four modified starches, porous starch, cross-linked starch,mulitiplicity-treated of enzymolysis, and cross-linked starch using enzymatic method or STPP(sodium tyipolyphosphate) as a chemical cross-linking agent. The thermodynamics properties of the raw corn starch and four modified starches were analyzed using differential scanning calorimetry(DSC). The properties of the adsorption of salad oil, methylene blue and Cu2+ of the modified starches were investigated. Endothermic enthalpy(△H) of the modified starch made by enzymatic modification was greater than that of the raw starch. The stability of the cross-linked starch increased and its endothermic enthalpy decreased. In addition, the cross-linking agent had greater influence on the endothermic enthalpy(△H) of multiplicity-treated starch compared to the enzymatic modification method. The multiplicity-treated starch via enzymatic hydrolysis had a good property of absorption, which is able to adsorb more functional matters, such as lipid, pigment, and heavy metals.