Preparation Of Oxidized Starch And Application In The Production Of Multi-modified Starch

The technology to prepare oxidized starch was investigated using tapioca starch as raw material. Studies were also carried out on the difference in properties of oxidized starch using different raw starch (potato starch, tapioca starch and wax corn starch).Then the research of using oxidization technology to improve the properties of tapioca crossed-linked and esterified starch was studied. In the end, there was a design of a set of 10000 tons multi-modified (oxidized) starch producing line, from the view of technology.Firstly, the preparation of oxidized tapioca starch using sodium hypochlorite was researched. Single factorial experiments were performed to probe the effect of pH(constant and inconstant), reaction temperature, the quantity of sodium hypochlorite addition, and reaction time on carboxyl group content, whiteness, viscosity and transparency of the resulting oxidized starch. The optimum conditions was obtained as follows: amount of sodium hypochlorite addition is 2%(D.S.), pH 8.5,reaction temperature was usual temperature, not control temperature, and reaction time is 8 hours.Secondly, studies were also carried out on the difference in properties of oxidized starch using different raw material srarch(potato, tapioca and wax corn) using different usage of sodium hypochlorite. The conclusions were: wax corn starch was not very suitable as raw material starch to prepare oxidized starch as far as reaction efficiency be concerned, because of its low reaction efficiency(compare to potato and tapioca starch). The whiteness of potato starch after oxidization is not very good as compared with tapioca starch because of its high content of impurity (compare to tapioca starch).As the same time, potato starch has disadvantage in high concentration use by oxidization to low viscosity because of its high viscosity. Using tapioca starch as raw material to prepare oxidized starch is better if we need the oxidized starch with low viscosity,can be used with high concentration starch slurry, and good transparency, good whiteness, low retrogradation and syneresis.Then, the research of using oxidization technology to improve the properties of tapioca crossed-linked and esterified starch was also researched: under the conditions of 0.2%(D.S.) usage of sodium hypochlorite, pH8.5(constant),usual temperature ,prepare oxidized starch using tapioca crossed-linked and esterified starch as raw material starch, it can greatly increase the transparency and improve the application properties and remain the application properties of crossed-linked and esterified starch as the same time.