Synthesis Of Oxidized Starch And Application In The Edible Film

For overcoming disadvantage of a traditional oxidant, such as the complex operation to synthesize oxidized starch and low oxidized degree of production, as a new innocuous oxidant, ClO2 were used to synthesize oxidized starch. And then the oxidized starch-based films were synthesized and characterized.In order to produce the oxidant (ClO2), two methods were studied. HCl was an activator to activate the ClO2 from the stable form. ClO2 was synthesized by means of which NaClO3 was deoxidized by a reducing agent HCl, and the acid bath was supplied by H2SO4. Effects of amounts and ratio of reactants, reaction temperature and reaction time on the oxidizing reaction were analyzed by carboxyl groups content and viscosity of oxidized starch.The morphology and structure of the oxidized starch was characterized by scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Infrared Spectroscopy (IR) and X-ray diffraction. Physical and chemical properties of oxidized starch were analyzed. Results showed that there were carboxyl groups and carbonyl groups in oxidized starch. Oxidation did not result in any significant changes in the degree of crystallinity of starch, implying that oxidation took place mainly in the amorphous region. Compare with the native starch, oxidized starch had lower retrogration, higher clarity, lower viscosity and lower relative molecular weight. The edible oxidized starch-based film was synthesized by oxidized starch, plasticizer (glycerol), rein forcer (sodium alginate). Effects of concentration of glycerol, sodium alginate and oxidized starch, reaction temperature, reaction time on capability of the film were analyzed according to tensile strength and elongation. Results showed that primary influencing factor on Tensile Strength was concentration of oxidized starch, primary influencing factor on elongation was concentration of glycerol, and primary influencing factor on blob permeation time was concentration of glycerol.The pattern of XRD showed by the oxidized starch based-film was B-type. Compare with native starch based-film, the oxidized starch based-film had higher Tensile Strength, Water vapor permeation and water-solubility. Water vapor permeation and water-solubility became higher according to higher carboxyl groups content of oxidized starch.