| Focused on those defects of starch structure and properties, such as unstableproperties of starch paste under the actions of acid, heat and mechanical stirring,easily aging, insoluble in cold water and unable to meet special demangds duringthe industrial production, Preparation and development of novel modified starchchanging molecular structure by adding functional groups or introducingsubstituent groups are important ways to expand application scope of starch andimprove its additional value. Combination modified starches prepared by two ormore kinds of methods are able to improve properties of original starch and obtain serial andmultiple performance productions. In this papar, preparation and application ofmodified waxy corn starch were investigated to wide use range, add its additionalvalue, and it is practically important significance and research value fordeveloping agriculture and agricultural products.“White pollution” and shortage of resources are still important problems inthe world. Research and development of degradable and recycled packagingmaterials are key ways to solve this problem. Edible packaging materials becomeone kind of important ways for "green packaging" or "environmental friendlymaterial". Although large-scale industrial production and successful applicationsfor edible paper made of bean dregs, vegetables and starched in Japan, ediblepackaging container used to potato products in Australia, edible packagingmaterials are still in the stage of laboratory research in world.Because engineering properties of edible packaging materials are not goodenough to satisfy the requirements of industrial production and commercialapplications such as barrier performance, mechanical properties and heat sealingstrength, etc, new modified starch as edible packaging materials was used toimprove its engineering performances and accelerate the process of massproduction of edible packing materials in this thesis.In this paper, cross-linked,oxidized, crosslink-oxidized, microporous, microporous cross-linked starch and microporouscrosslinked oxidized starch were prepared with waxy corn starch as raw material using biologically enzymolysis, chemically modified or combination modified methods ofbiologically enzymatic hydrolysis and chemical compound. Firstly, quadratic regressionorthogonal combination experiments design was applied, then the data were analysized byregression and ANOVA based on above-mentioned experimental results and varianceanalysis to obtain the optimum preparation conditions. At the same time, optimal regressionequations which can reflect the relationship between test indexes and influence factors wereestablished, and verification experiments were used to verify the results’ stabilities ofoptimal preparation conditions and repeatability. Using modern detection techniquessuch as Fourier transform infrared spectroscopy, X-ray diffraction (XRD) andscanning electronic microscopy (SEM), structure and particles morphology ofmodified starches were characterized analysize to provide theoretical references andexperimental basis for the research and development of modified starch in the future.Performance comparison and qualitative description of a variety of modified waxycorn starch samples had been completed. Finally, application researches ofadsorption performance of microporus starch and edible packaging film based onlipid compound modified starch were carried out in order to widen the applicationrange of modified starches.The innovation of this paper are as follows:Firstly, a novel type of composite waxy corn modified starch bymicroporous-cross-linked-oxided methods was prepared. The starch possessed betterexpansion degree, solubility, transparency; excellent stability of paste liquid, film-formingproperty and adsorption characteristcs. And it was applied to prepare edible packaging filmbased on lipids-starch and achieved desired results. Its main engineering performances weretested and compared with original starch. And results showed that the novel starchpossessed triple collaboration functions of microporous, crosslinking, oxidation. Preparededible packaging film based on lipid starch was more better than single edible packagingfilm based on lipids waxy corn starch and lipid potato starch for enginerring performance.Application of microporous modified starch has not reported in edible packaging film bynow.Secondly, quantitative test of low field nuclear magnetic resonance (NMR) technologyis firstly applied to study of adsorption of microporous starch. Experimental results showedthat it is effective，accurate，and fast as a quantitative detection method for oil adsorption rateof microporous starch, and is potential research tool. Oil adsorption quantity ofmicroporous starch is620mg/g precisely. Outcomes in this thesis enable to provide theoretical basis and experimentalfoundation for the development and industrial production of modified starch andedible packaging materials... |
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